JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
PAGES 353^391
2008
doi:10.1093/petrology/egm085
Mafic and Felsic Magma Interaction in
Granites: the Hercynian Karkonosze Pluton
(Sudetes, Bohemian Massif)
E. SABY1* AND H. MARTIN2
1
INSTITUTE OF GEOCHEMISTRY, MINERALOGY AND PETROLOGY, FACULTY OF GEOLOGY,
UNIVERSITY OF WARSAW, AL.Z_ WIRKI I WIGURY 93, 02-089 WARSZAWA, POLAND
2
LABORATOIRE MAGMAS ET VOLCANS; OPGC, CNRS, UNIVERSITE¤ BLAISE PASCAL, 5, RUE KESSLER, 63038
CLERMONT-FERRAND, FRANCE
RECEIVED JANUARY 23, 2007; ACCEPTED DECEMBER 12, 2007
ADVANCE ACCESS PUBLICATION JANUARY 18, 2008
The Hercynian, post-collisional Karkonosze pluton contains several
lithologies: equigranular and porphyritic granites, hybrid quartz
diorites and granodiorites, microgranular magmatic enclaves, and
composite and lamprophyre dykes. Field relationships, mineralogy
and major- and trace-element geochemistry show that: (1) the equigranular granite is differentiated and evolved by small degrees of
fractional crystallization and that it is free of contamination by
mafic magma; (2) all other components are affected by mixing. The
end-members of the mixing process were a porphyritic granite and a
mafic lamprophyre.The degree of mixing varied widely depending on
both place and time. All of the processes involved are assessed quantitatively with the following conclusions. Most of the pluton was
affected by mixing, implying that huge volumes (475 km3) of mafic
magma were available. This mafic magma probably supplied the
additional heat necessary to initiate crustal melting; part of this
heat could have also been released as latent heat of crystallization.
Only a very small part of the Karkonosze granite escaped interaction
with mafic magma, specifically the equigranular granite and a subordinate part of the porphyritic granite. Minerals from these facies
are compositionally homogeneous and/or normally zoned, which,
together with geochemical modelling, indicates that they evolved by
small degrees of fractional crystallization (520%). Accessory
minerals played an important role during magmatic differentiation
and, thus, the fractional crystallization history is better recorded by
trace rather than by major elements. The interactions between mafic
and felsic magmas reflect their viscosity contrast. With increasing
viscosity contrast, the magmatic relationships change from
homogeneous, hybrid quartz diorites^granodiorites, to rounded magmatic enclaves, to composite dykes and finally to dykes with chilled
margins.These relationships indicate that injection of mafic magma
into the granite took place over the whole crystallization history.
Consequently, a long-lived mafic source coexisted together with the
granite magma. Mafic magmas were derived either directly from
the mantle or via one or more crustal storage reservoirs. Compatible
element abundances (e.g. Ni) show that the mafic magmas that
interacted with the granite were progressively poorer in Ni in the
order hybrid quartz dioritesçgranodioritesçenclavesçcomposite
dykes.This indicates that the felsic and mafic magmas evolved independently, which, in the case of the Karkonosze granite, favours a
deep-seated magma chamber rather than a continuous flux from
mantle. Two magma sources (mantle and crust) coexisted, and
melted almost contemporaneously; the two reservoirs evolved independently by fractional crystallization. However, mafic magma was continuously being intruded into the crystallizing granite, with more or
less complete mixing. Several lines of evidence (e.g. magmatic flux
structures, incorporation of granite feldspars into mafic magma, feldspar zoning with fluctuating trace element patterns reflecting rapid
changes in magma composition) indicate that, during its emplacement and crystallization, the granite body was affected by strong
internal movements.These would favour more complete and efficient
mixing. The systematic spatial^temporal association of lamprophyres with crustal magmas is interpreted as indicating that their
mantle source is a fertile peridotite, possibly enriched (metasomatized) by earlier subduction processes.
*Corresponding author. Telephone: þ48 22 55400308. Fax: þ48 22
5540001. E-mail: [email protected]
ß The Author 2008. Published by Oxford University Press. All
rights reserved. For Permissions, please e-mail: journals.permissions@
oxfordjournals.org
JOURNAL OF PETROLOGY
KEY WORDS: Bohemian Massif; fractional
geochemical modelling; hybridization; Karkonosze
VOLUME 49
crystallization;
I N T RO D U C T I O N
It has long been recognized that granitic bodies result from
a complex interplay of several petrogenetic processes. The
present-day composition of any granite has been determined by processes that cannot always be easily separated,
determined and quantified. Many granite masses contain
hybrid rocks; pointing to the coexistence of two or more
compositionally contrasting magmas (Didier, 1973; Didier
& Barbarin, 1991; Bateman, 1995; Wiebe, 1996; Barbarin,
1999, 2005; Barnes et al., 2001; Wiebe et al., 2002; Bonin,
2004, 2007; Janous› ek et al., 2004; Kerim, 2006). As summarized by Barbarin (2005), these hybrid rocks provide evidence of the important role played by mafic magmas in
the generation and evolution of calc-alkaline granitoid
magmas. Thus understanding their origin is of fundamental significance in interpreting the history of granitic
batholiths.
It is now well established that hybrid rocks represent different stages of interaction between mafic and felsic
magmas (see Janous› ek et al., 2004; Barbarin, 2005, for
review). However, the conditions and detailed mechanisms
of these interactions remain hotly debated. Unfortunately,
until now, most research strategies, based on only one tool,
have seemed inadequate to resolve the problem; rather, a
multi-faceted approach is required. For instance, a wholerock geochemical approach alone does not provide an
unequivocal petrogenetic model because the linear trends
in binary diagrams can result not only from mixing but
also from small degrees of fractional crystallization.
Similarly, small, hybrid magma bodies could have chemically re-equilibrated with their host magma and consequently their composition no longer reflects their initial
magmatic chemistry (Watson, 1982; Wall et al., 1987;
Castro et al., 1990; Fourcade et al., 1992; Elburg, 1996;
Waight et al., 2000).
There are numerous processes that can make it difficult
to establish clear chronologies for magma mixing events.
For instance, many magmatic structures indicate that
granitic magmas experience dynamic flow during
emplacement and/or during internal convection (Barrie're,
1981). Similarly, as granite crystallization can span long
time periods (Annen et al., 2006), there is ample opportunity for the injection of multiple discrete pulses of mafic
magma. Some studies (Zorpi et al., 1989, 1991; Bouchet,
1992) have demonstrated that the compositions of interacting granitic and mafic magmas may both evolve over time.
Indeed, during cooling, fractional crystallization may take
place in tandem with mixing, thus increasing the ultimate
complexity of the pluton. Depending on the degree of crystallization, the mode of interaction between a cooling
NUMBER 2
FEBRUARY 2008
granite and an injected mafic magma can varyçfor example, as expressed in thorough mixing (blending), or the
presence of rounded enclaves, composite dykes and intrusive dykes (Hallot et al., 1994, 1996; Barbarin, 2005)çsuch
that it is often difficult to establish an accurate chronology
of mafic magma emplacement.
Consequently, the aim of this paper is to address the
question of magma interactions during the course of granite crystallization and to determine their effects on the
overall compositions. The work is based on field observations, petrography and geochemistry. The processes identified are modelled and their relative importance is assessed.
The well-exposed Karkonosze granite in the Hercynian
Sudetes (Bohemian Massif) has been chosen as a suitable
case study. Earlier studies (Berg, 1923; Cloos, 1925;
Borkowska, 1966; Klominsky, 1969) have documented the
abundance of rounded mafic microgranular magmatic
enclaves (MME) and dykes in the granite. A detailed
mineralogical investigation of the granite and its magmatic
enclaves, using cathodoluminescence and mineral chemistry, has already demonstrated that the minerals of the
granite reveal a complex growth history (Saby &
Galbarczyk-Ga˜ siorowska, 2002; Saby & Go«tze, 2004;
Saby et al., 2007a, 2007b). These results are used here,
together with whole-rock geochemistry data, further to
elucidate the history of mafic and felsic magma interaction
in the Karkonosze intrusion.
A N A LY T I C A L M E T H O D S
Minerals were analysed at the Inter-Institute Analytical
Complex for Minerals and Synthetic Substances, Warsaw
University, using a Cameca SX-100 electron microprobe
(10 s counting times; 15 kV acceleration voltage and 20 nA
beam current for major elements and 20 kV and 50 nA for
trace elements; beam diameter 5 mm). Applying a Monte
Carlo simulation (Robert & Casella, 2004), the interaction
depth of the electron beam with the sample was less than
5 mm. Feldspar and biotite analyses were recalculated on
the basis of eight and 22 oxygens, respectively. Amphibole
formulae were calculated following Droop’s (1987) schema
No. 6 (assuming 13 cations and excluding Ca, Na, K)
Major elements (SiO2, TiO2, Al2O3, Fe2O3t, MnO,
MgO, CaO, Na2O, K2O, P2O5) and some trace elements
(Ba, Sr, Zr) were determined at the Institute of Geological
Sciences UAM, Poznan¤, using an XRF S4 Explorer.
Glass beads were made from a mixture of lithium tetraborate and sample powder in the proportion 1:5. The accuracy
for major elements is 52%, and for trace elements 510%.
The remaining trace elements [Ni, Nb, Rb, Th, rare earth
elements (REE)] were analysed at the ACME Analytical
Laboratories, Vancouver (Canada), by inductively coupled
plasma mass spectrometry (ICP-MS) (REE and refractory
elements by lithium tetraborate fusion and base metals by
354
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
aqua regia digestion). All analyses were recalculated on
an anhydrous basis, with iron expressed as Fe2O3t ¼
Fe2O3 þ1111 FeO (see Tables 8^12).
Nd isotope analyses were performed on 100 mg powdered samples at the Institute of Geological Sciences of
the Polish Academy of Sciences, Warsaw, using a VG
Sector 54 mass spectrometer in multi-collector dynamic
mode. 143Nd/144Nd ratios were normalized to
146
Nd/144Nd ¼ 07219. Time-related calculations use values
of 143Nd/144Nd ¼ 0512638 and 147Sm/144Nd ¼ 01967 for
the present-day depleted mantle following a radiogenic
linear growth for the mantle with eNd ¼ 0 at 4568 Ga.
GEOLOGIC A L S ET T I NG
The Carboniferous Karkonosze pluton is a part of the midEuropean segment of the Hercynian orogenic belt that
reflects the convergence of Gondwana and Laurasia
during Palaeozoic times (Matte, 1986; Ziegler, 1986; Finger
& Steyrer, 1990; Matte et al., 1990; Dallmeyer et al., 1995;
Franke, 2000; Franke et al., 2005). In this orogenic belt, convergence and subsequent continent^continent collision led
to the emplacement of many granite bodies (Finger et al.,
1997). The greatest magmatic activity took place during
the Late Carboniferous and was related to transpressional^transtensional tectonics (Finger & Steyrer, 1990;
Diot et al., 1995; Mazur & Aleksandrowski, 2001). The
Karkonosze pluton (the Krkonos› e^Jizera Plutonic
Complex, the Krkonos› e^Jizera pluton, Krkonos› e^Jizera
massif in the Czech literature and the Riesengebirge in
German literature) intruded into the Saxothuringian zone
of the Hercynian belt (Fig. 1a).
The pluton is located in the Western Sudetes on the
northern extremity of the Bohemian Massif. The Sudetes
resulted from the accretion of four major terranes during
the Hercynian (Aleksandrowski & Mazur, 2002).
The pluton and its metamorphic envelope have been studied geologically for more than a century. The different
models for its genesis and emplacement have been
reviewed by Mierzejewski & Oberc (1990). Karkonosze is
surrounded by several structural units (Izera^Kowary,
South Karkonosze Metamorphic Complex) of contrasting
lithostratigraphic and metamorphic evolution. These units
are interpreted as being a Late Devonian^Early
Carboniferous nappe pile (Mazur & Aleksandrowski,
2001; Aleksandrowski & Mazur, 2002) intruded by the
late to post-collisional Karkonosze granite (Duthou et al.,
1991; Diot et al., 1995; Mazur, 1995; Wilamowski, 1998)
during the extensional collapse of the chain (Matte, 1998).
The Karkonosze pluton is an east^west elongate body
extending for c. 70 km with a minimum width of 20 km.
Following the nomenclature of Barbarin (1999), the granite
is a typical K-rich calc-alkaline granite (KCG). Pin et al.
(1987) and Duthou et al. (1991) obtained whole-rock Rb^Sr
isochron ages of 328 12 Ma and 329 17 Ma for the porphyritic granite. For the same facies Kro«ner et al. (1994)
determined an age of 304 14 Ma by Pb^Pb zircon
evaporation and Marheine et al. (2002) an age of
320 2 Ma by the 40Ar^39Ar method on biotite. The equigranular granite has been dated at 310 14 Ma by the
Rb^Sr whole-rock method (Duthou et al., 1991), whereas
40
Ar^39Ar on biotite yielded an age of 315 2 Ma
(Marheine et al., 2002).
The Karkonosze mass consists mainly of biotite-bearing
porphyritic to equigranular granite, small volumes of twomica granite and subordinate granodiorite (Berg, 1923;
Borkowska, 1966; Klominsky, 1969). The granite is cut by
lamprophyre and aplite dykes (Berg, 1923; Borkowska,
1966; Awdankiewicz et al., 2005a, 2005b). A two-mica granite occurs at the south and SW margins of the pluton. Both
its mineral and chemical composition are drastically different from the rest of the Karkonosze pluton. Klominsky
(1969) and Z›ak et al. (2006) considered this to be an independent early magma pulse. It is not discussed further in
this paper.
Recently, it has been proposed that the Karkonosze
intrusion is of mixed mantle^crustal origin (Saby &
Go«tze, 2004; Saby & Martin, 2005). Granodiorites, occurring as large irregular zones, microgranular magmatic
enclaves and ductile stretched dykes, were considered
hybrid facies by Saby & Martin (2005; see also below).
The hybrid zones vary in scale from several tens of metres
to several kilometres. Larger hybrid screens 512 km in
length delineate contacts between separate injections of
granitic magma (Z›ak & Klominsky, 2007). Magmatic
structures recognized in the porphyritic granite by Z›ak &
Klominski (2007) indicate highly localized magma flow
after chamber-wide mixing. Magma movement was
coupled with magma segregation (biotite schlieren), compaction, filter pressing, gravitational differentiation and
other processes taking place in crystal-rich mushes. The
present study is focused on the evolution of magmatic
liquids and we avoided sampling these places.
Geochemical data prove the non-cumulative character of
the collected samples.
Lamprophyre dykes ranging up to few metres in width
occur in the eastern part of the Karkonosze intrusion to
the SE of Jelenia Go¤ra and above the inferred feeder conduit of the pluton (Mierzejewski & Oberc, 1990;
Awdankiewicz et al., 2005a, 2005b). Sharp contacts with
the granite are accentuated by occasional chilled margins.
The genetic relationships with the granite are not clear;
some lamprophyres are arguably related to late porphyritic
granites, others are mafic dykes younger than the porphyritic granite (see details below). Aplite dykes are
comagmatic with the granite and in many places can be
viewed as melt expelled as a result of filter pressing.
355
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Fig. 1. Geological map of the West Sudetes adapted after Mazur & Aleksandrowski (2001). (a) Position of the Karkonosze granite within the
West Sudetes; inset shows the Bohemian Massif (grey area) and Saxothuringian (SX) and Moldanubian (MO) zone within mid-European
segment of Hercynian orogenic belt. ISF, Intra-Sudetic fault; SBF, Sudetic boundary fault; L, Lusatian granitoid massif; I-K, Izera^Kowary
unit; SKMC, South Karkonosze Metamorphic Complex; KZU, Kodzko^Zoty Stok unit; GS, Go¤ry Sowie. (b) Distribution of Karkonosze
granite facies and sampling localities. POR, porphyritic granite; EQU, equigranular granite; HYB, hybrid quartz diorite and granodiorite;
COM, composite dyke; LAM, lamprophyre.
P E T RO L O G Y
During the last 85 years, the Karkonosze pluton has been
the subject of a number of petrological studies (e.g. Berg,
1923; Cloos, 1925; Borkowska, 1966; Klominsky, 1969).
Below we give a brief summary of previously published
and new data on the most important features of the
Kakonosze rocks. Sample localities are given in Fig. 1b
and in Table 1.
356
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Granite
Equigranular granite (EQU)
This granite facies is a fine- to medium-grained, equigranular, biotite graniteçthe ‘ridge’ granite of Borkowska
(1966) and the ‘crestal’ and ‘Harrachov’ granite of Z›ak &
Klominsky (2007). It crops out in the central and eastern
parts of the pluton and as small scattered bodies in the porphyritic facies (Fig. 1b). The grain size varies from 5 to
1mm (Fig. 2a) with the progressive transition from
medium- to fine-grained rock. Pockets of biotite granite
with granophyric texture are occasionally found (Fig. 2b).
The equigranular granite contains K-feldspar (36^18 vol.
%), plagioclase (35^25 vol. %), quartz (42^30 vol. %), biotite (6^1vol. %), small amounts of muscovite (501%) and
accessory apatite, zircon, allanite, titanite, epidote, magnetite, ilmenite and monazite (Borkowska, 1966). Apart from
occasional larger quartz crystals (Fig. 2a), the granite is
very homogeneous without megacrysts, microgranular
magmatic enclaves (MME) or mafic schlieren. In a few
places it is cut by composite dykes.
Porphyritic granite (POR)
The porphyritic graniteçthe ‘central granite’ of
Borkowska (1966) and the ‘Liberec and Jizera’ granite of
Z›ak & Klominsky (2007)çis the most widespread facies
of the Karkonosze pluton (Figs 1b and 2c^f). This granite
contains anhedral^subhedral K-feldspar (13^35 vol. %),
subhedral^euhedral plagioclase (25^48 vol. %), anhedral
quartz (21^40 vol. %), biotite (4^21vol. %), occasional
subhedral amphibole (0^3 vol. %) and accessory apatite,
zircon, allanite, titanite, magnetite, ilmenite and monazite.
The medium- to coarse-grained matrix has the same texture as the equigranular granite whereas the K-feldspar
megacrysts can be 5 cm long and 3 cm wide (Fig. 2d
and e). Plagioclase megacrysts are rare. In some places,
where K-feldspar megacryst accumulations occur, the
matrix is almost absent from what appears to be a megacryst-rich mush. The porphyritic granite is rich in various
types of hybrid, mostly MME (Fig. 2f), and in small isolated bodies of hybrid quartz diorite and granodiorite. In
most places, elongated enclaves and megacrysts define a
magmatic foliation. Interactions between the hybrids and
the host granite involve the introduction of K-feldspar
megacrysts into MME and of quartz ocelli into hybrid
quartz diorites and granodiorites (Fig. 2c). Locally, biotite
schlieren are abundant (Fig. 2g).
Hybrid rocks
Hybrid quartz diorite^granodiorite (HYB)
These mesocratic^melanocratic rocks represent zones of
mafic^felsic magma mixing; Klominsky (1969) called
them the ‘Fojtka granodiorite’ whereas Borkowska (1966)
described them as ‘lamprophyre and granite porphyry’.
Hybrid quartz diorite^monzodiorite^granodiorite are
exclusive to the porphyritic granite. Their texture is porphyritic to equigranular (Fig. 2g^i) and their minerals
show growth textures compatible with magma mixing
and variable, oval to almost subhedral^euhedral habits.
The mineral assemblage is plagioclase, quartz, K-feldspar,
amphibole and biotite and subordinate amounts of apatite,
zircon, titanite, magnetite and ilmenite. Because of the
abundance of biotite and amphibole these rocks are dark
in colour. However, they often contain large pink K-feldspar crystals mantled with white plagioclase rims
(Fig. 2g). Feldspar megacrysts commonly lie across the
border between hybrid and porphyritic granite; together
with the rapakivi texture, this is indicative of the mechanical introduction of granite megacrysts into a hybrid
magma. Hornblende- and biotite-mantled quartz ocelli
are abundant (Fig. 2i).
Microgranular magmatic enclaves (MME)
Centimetre- to metre-sized MME consist mainly of a fineto medium-grained assemblage of subhedral plagioclase
and biotite, variable amounts of euhedral^subhedral hornblende and accessory titanite, apatite, ilmenite, magnetite
and zircon. Single plagioclase megacrysts or glomerophyric plagioclase clusters, commonly with syneusis texture,
occur in or adjacent to the enclaves. They display boxycellular texture and an inner spiky zone (Wnorowska,
2006; Saby et al., 2007a). All plagioclase megacrysts
show a narrow, marginal reaction rim; similarly, all
alkali-feldspar megacrysts have a narrow rapakivi rim
(Fig. 2f). Biotite and hornblende occasionally form mafic
clots. Plagioclase^hornblende intergrowths are common,
as are quartz ocelli. Enclaves are always rounded or
lobate, which, together with the mineral-growth textures,
strongly suggests the coexistence and mixing of two
magmas.
Composite dykes (COM)
Many dykes (2^3 m thick) intrude both the porphyritic
and equigranular granites. They consist of broken and
ductilely deformed mafic bodies (Fig. 2j) ranging from
monzodiorite to granodiorite in composition. They are
medium-grained (2^3 mm) and show a bimodal crystal
distribution with subhedral hornblende, biotite, plagioclase
and slightly larger anhedral quartz and alkali feldspar.
Accessory apatite, zircon, allanite and ilmenite are very
abundant. The composite dykes contain mafic clots of biotite and hornblende surrounded by quartzo-feldspathic
rims. Plagioclase crystals mantled by alkali feldspar (antirapakivi) and alkali feldspar mantled by plagioclase
(rapakivi) are common.
Lamprophyres (LAM)
Lamprophyres form dyke swarms cutting the porphyritic
granite. They are mainly fine-grained (51mm) kersantites
357
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Table 1: Sample location, classification and qualitative modal composition
Sample
Latitude (North)
Longitude (East)
QAPF classification
Mineralogical composition
Qtz
Afs
Pl
Am
Bt
Op
Acc
EQU-1
508500
158550
granite
EQU-2
0
50847
158350
granite
EQU-3
508440
158430
granite
EQU-4
508540
158500
granite
EQU-5
508470
158310
granite
EQU-6
508460
158400
granite
EQU-7
508520
158530
granite
EQU-8
508520
158550
granite
EQU-9
508530
158440
granite
EQU-10
508460
158500
granite
EQU-11
508470
158320
granite
EQU-12
508510
158520
granite
EQU-13
508550
158470
granite
EQU-14
508470
158360
granite
EQU-15
508510
158520
granite
POR-1
508500
158110
granite
POR-2
508500
158120
granodiorite
POR-3
508480
158440
granite
POR-4
508470
158430
granite
POR-5
508520
158100
granite
POR-6
508480
158460
granite
POR-7
508480
158390
granite
POR-8
508520
158490
granite
POR-9
508520
158510
granite
POR-10
508500
158380
granite
POR-11
508510
158440
granodiorite
POR-12
508500
158520
granite
POR-13
508490
158500
granite
POR-14
508470
158410
granite
POR-15
508510
158430
granite
POR-16
508490
158140
granodiorite
POR-17
508470
158100
granite
POR-18
508520
158440
granite
POR-19
508500
158490
granodiorite
POR-20
508470
158110
granite
POR-21
508520
158520
granite
POR-22
508520
158450
granite
POR-23
508530
158440
granite
POR-24
508500
158350
granite
POR-25
508490
158220
granite
POR-26
508490
158310
granite
HYB-1
508470
158060
quartz diorite
HYB-2
508470
158060
quartz diorite
HYB-3
508500
158040
quartz monzodiorite
(continued)
358
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Table 1: Continued
Sample
Latitude (North)
Longitude (East)
QAPF classification
Mineralogical composition
Qtz
Afs
Pl
Am
Bt
Op
Acc
HYB-4
508500
158000
quartz monzodiorite
HYB-5
0
50850
0
15804
quartz monzodiorite
HYB-6
508500
158040
quartz monzodiorite
HYB-7
508500
158040
quartz monzodiorite
HYB-8
508500
158040
granodiorite
HYB-9
508500
158040
granodiorite
HYB-10
0
50847
158060
granodiorite
HYB-11
508470
158060
granodiorite
HYB-12
508500
158050
granodiorite
MME-1
0
50850
158290
quartz monzodiorite
MME-2
508490
158310
granodiorite
MME-3
508490
158310
granodiorite
MME-4
508500
158370
granodiorite
MME-5
508500
158370
granodiorite
MME-6
508490
158490
granodiorite
COM-1
508490
158520
quartz monzodiorite
COM-2
508520
158520
granodiorite
COM-3
508490
158490
granodiorite
COM-4
508520
158520
granodiorite
COM-5
508490
158510
granodiorite
COM-6
508470
158340
granodiorite
LAM-1y
lamprophyre
LAM-2
508520
158520
lamprophyre
n.d.
LAM-3
508500
158510
lamprophyre
n.d.
LAM-4
508490
158460
lamprophyre
Based
y
on CIPW norm.
Sample provided by A. Wilamowski.
Qtz, quartz; Afs, alkali feldspar; Pl, plagioclase; Am, amphibole; Bt, biotite; Op, opaque minerals; Acc, accessory
minerals; , significant amount; , subordinated; n.d., not determined.
and malchites (Borkowska, 1966) containing euhedral
plagioclase (oligoclase), amphibole, biotite and magnetite
together with sporadic, interstitial quartz and alkali feldspar. Pyroxene, olivine, titanite and apatite are subordinate.
MI NER A L COMPOSITION
All the facies of the Karkonosze pluton have similar
mineral assemblages; they differ in the relative abundances
of the minerals, growth textures and compositions. The
two latter aspects are the focus of the following discussion.
Alkali feldspar
Megacrysts
Alkali megacrysts are restricted to the porphyritic granite
and hybrids. All show growth zoning that irregularly
and recurrently evolves from relatively Ab-rich cores
(Or60^65Ab40^34An0^1) to Or-rich rims (Or83^97Ab17^
3An0) (Table 2). The zones are outlined by plagioclase^biotite lath trails and frequently show dissolution^regrowth
textures. Many megacrysts reveal a complex polyphase
(plagioclase and quartz) mantled rapakivi texture. Their
trace-element patterns, in particular, indicate that the
alkali feldspar grew in a heterogeneous magma composed
of coherent and active regions in the sense of Perugini et al.
(2003). Based on Ba, light REE (LREE) and Pb isotope
characteristics, Saby et al. (2007a, 2007b) concluded that
the megacrysts formed in a magma-mixing regime involving two end-members, rich and poor respectively in large
ion lithophile elements (LILE). Cathodoluminescence studies of megacrysts in the hybrids revealed an additional
type of zoning interpreted as reflecting changes in the
359
JOURNAL OF PETROLOGY
VOLUME 49
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
NUMBER 2
FEBRUARY 2008
Fig. 2. Representative rock textures. (a) Equigranular medium-grained granite; the larger grey quartz grains should be noted (Haslerova
Chata, Czech Republic); (b) equigranular granite with granophyric zone (Szklarska Poreba Huta, Poland); (c) biotite schlieren with alkali
feldspar megacrysts in porphyritic granite (Kamien¤czyk river-bed near Piechowice, Poland); (d) porphyritic granite with alkali feldspar megacrysts (Karpacz, Poland); (e) alkali feldspar megacryst in porphyritic granite; zonal growth morphology marked by trails of biotite and plagioclase laths should be noted (Michaowice, Poland); (f) alkali feldspar megacryst in microgranular magmatic enclave; narrow marginal rim of
lighter pink colour as well as a similar zone encircling the poikilitic core (alkali feldspar þ biotite), both dotted with small plagioclase inclusions, reflect reaction between the megacryst and the surrounding commingled magma (Mrowiec Hill, Poland); (g) hybrid granodiorite; the
porphyritic texture comprises rapakivi alkali feldspar megacrysts, mafic clots and ocellar, hornblende-mantled quartz (Rudolfov, Czech
Republik); (h) hybrid granodiorite with quartz diorite enclave (Rudolfov, Czech Republik); (i) equigranular medium- to coarse-grained
hybrid granodiorite; hornblende-mantled biotite plates, mafic inclusions in a more felsic host and ocellar quartz make the rock dark (Fojtka,
Czech Republik); (j) stretched and broken composite granodiorite dyke (near Karpniki, Poland).
360
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Table 2: Representative analyses of alkali feldspars
EQU-1
EQU-12
POR-1
POR-1
POR-1
POR-23
POR-23
POR-23
HYB-5
HYB-1
MME-1
COM-1
matrix
matrix
megacryst
megacryst
matrix
megacryst
megacryst
matrix
megacryst
matrix
matrix
matrix
core
rim
core
rim
wt %
SiO2
6330
6475
6539
6446
6503
6458
6495
6433
659
6435
6589
6562
Al2O3
1948
1822
1862
1822
1851
1832
1843
1822
1871
1884
1863
1841
CaO
002
003
006
001
002
003
5001
5001
006
023
014
001
BaO
023
003
147
047
038
033
5001
5001
022
032
008
012
Na2O
089
092
414
072
058
107
026
025
53
132
161
272
K2O
P
1458
1542
992
1594
1595
1490
1629
1597
659
1460
1397
1146
985
9937
9982
10047
9923
9993
9877
9993
9966
10032
9834
996
Si
296
300
301
300
300
298
299
300
299
297
308
302
Al
107
100
101
100
101
099
100
100
100
103
102
100
Ca
000
000
000
000
000
000
000
000
000
001
001
000
Na
008
008
037
007
005
010
002
002
047
012
015
024
K
P
087
091
058
095
094
088
096
095
056
086
083
067
498
499
497
502
500
495
497
497
502
499
509
493
Ab
833
833
3865
638
516
983
234
229
4511
1192
1476
2652
An
010
010
031
004
010
014
000
000
029
111
070
006
Or
9157
9157
6104
9358
9474
9003
9766
9771
5460
8697
8454
7342
density of structural defects (Saby & Go«tze, 2004). Zones
with high structural defect densities are correlated with
growth within active (poorly mixed) magma regions.
Matrix
Alkali feldspar is present in the matrix of all the granite
facies. The feldspars in the matrices of the hybrid diorite^
granodiorite, the MME and the composite dykes are characterized by growth zoning differing in structural defect
densities (Saby & Go«tze, 2004) and in trace-element characteristics. In contrast, matrix alkali feldspars in both the
porphyritic and equigranular granites are homogeneous;
compared with the megacrysts, they are richer in Or
(Table 2) and poorer in Ba and LREE.
Plagioclase
Megacrysts
In both porphyritic granite and hybrids, plagioclase megacrysts are less common than those of alkali feldspar and
are typically strongly altered. Although some display concordant zoning, most show a complex zoning pattern with
a patchy core (An52) surrounded by discordant and truncated zones of andesine^oligoclase. Commonly, discordances are separated by simple zoning. Thin marginal
rims of almost pure albite (Ab95^97) are interpreted as due
to subsolidus reaction (Table 3). Resorption^regrowth
textures are common within the complex zoning.
Cathodoluminescence study (Saby & Go«tze, 2004;
Wnorowska, 2006) shows that during their crystallization,
the plagioclase crystals migrated between variably mixed
mafic and felsic environments.
Matrix
Plagioclase crystals in the matrices of hybrid quartz diorite^granodiorite, MME and composite dykes, or included
in alkali feldspar megacrysts, have exactly the same
growth morphologies and compositions as the plagioclase
megacrysts (Saby & Go«tze, 2004; Wnorowska, 2006).
Some crystals from hybrid quartz diorite^granodiorite
and MME unequivocally have ternary feldspar compositions (Table 3, MME-2). The plagioclase in the matrices
of the porphyritic and equigranular granites is, in contrast,
oligoclase (An27^17) occasionally showing limited, continuous and concordant zoning. Thin marginal rims of almost
pure albite match the similar megacryst rims.
Quartz
Anhedral interstitial quartz is abundant in hybrids and in
porphyritic and equigranular granites. In all hybrids, occasional quartz megacrysts have a hornblende-mantled ocellar
texture. Cathodoluminescence reveals that the hybrid
megacrysts exhibit simple and complex zoning patterns
(Saby & Go«tze, 2004), whereas quartz from the granites is
homogeneous. Myrmekite is widespread in all facies.
361
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Table 3: Representative analyses of plagioclases
EQU-1
EQU-12
POR-1
POR-1
POR-23
HYB-1
HYB-8
HYB-8
MME-1
MME-2
COM-1
LAM-1
matrix
matrix
megacryst
megacryst
matrix
matrix
megacryst
megacryst
matrix
matrix
matrix
matrix
core
rim
core
rim
wt %
SiO2
6197
6737
5415
6047
6135
5204
5772
6219
6358
6423
6255
6580
Al2O3
2313
2026
2849
2444
2432
2965
2667
2371
2165
2176
2381
2220
CaO
512
106
1101
630
536
1213
857
476
319
219
482
177
BaO
005
004
003
006
009
5001
009
003
008
5001
002
008
Na2O
851
1099
527
779
833
439
654
884
964
824
874
895
K2O
P
060
019
010
038
027
007
014
022
058
9938
9991
9905
9944
9972
9828
9973
9975
9872
Si
277
295
247
261
265
240
259
276
278
Al
122
105
153
124
124
161
141
124
111
Ca
025
005
054
029
025
060
041
023
Na
074
093
046
065
070
039
057
K
P
003
001
001
002
001
000
501
499
501
481
485
5
Ab
7254
9396
4613
6768
7270
3944
5753
An
2411
503
5327
3021
2581
6016
Or
335
101
060
211
149
040
Biotite
Biotite is the most abundant ferromagnesian mineral in all
granite and hybrid facies and in some lamprophyres. It
occurs as euhedral^anhedral, strongly pleochroic, zoned
(hybrids) or homogeneous (equigranular granite) flakes
characterized by low AlVI contents (005^031a.p.f.u.),
almost constant AlIV and variable Fe/(Mg þ Fe) of
071^058 (Table 4). They plot in the annite^phlogopite
field in the annite^siderophyllite^phlogopite^eastonite
quadrilateral. Lamprophyres contain biotites with
Fe/(Mg þ Fe) as low as 019 (Awdankiewicz et al., 2005b).
Changes in biotite Alt, Ti, Fe and Mg concentrations
record magmatic evolution. Biotite Alt (a.p.f.u.) is almost
constant in the hybrid facies and porphyritic granite, but
increases in the equigranular granite (Table 4); this could
be interpreted to be the result of an increasing contribution
from aluminous crustal material (Shabani et al., 2003).
Biotite compositions evolve from Ti-rich (065 a.p.f.u.) and
low Fe/(Fe þ Mg) (02^035 a.p.f.u.) in lamprophyres, to
Ti-poor (03 a.p.f.u.) and higher Fe/(Fe þ Mg) (07 a.p.f.u.)
in equigranular granites (Fig. 3).
Amphibole
Amphibole is present only in the more mafic rock typesç
lamprophyres, hybrid quartz diorites^granodiorites, composite dykes and some porphyritic granites. Based on the
Leake et al. (1997) classification, are all calcic amphiboles
298
022
139
10016
10019
280
276
288
112
124
114
015
010
023
008
076
082
070
075
076
001
001
003
017
001
008
499
5
489
489
499
494
7615
8163
7178
7573
8248
4166
2265
1506
1062
2305
903
081
120
331
1760
122
849
994
(CaB 415), but they differ significantly in their SiT,
(Na þ K)A and Mg/(Mg þ Fe). Amphibole in lamprophyres is a magnesio-hastingsite [silica- and iron-poor,
Mg/(Mg þ Fe) ¼ 078^087 a.p.f.u.]. Because of variable
Mg/(Mg þ Fe) values (046^053 a.p.f.u.), amphiboles in
hybrid quartz diorites^granodiorites range from magnesio- to ferro-hornblende (Table 5). Composite dykes contain hastingsite (silica-poor, and iron-rich). As for biotite,
amphibole Ti contents and Mg/(Mg þ Fe) decreased
during magma differentiation (Fig. 3).
As the Karkonosze rocks contain eight solid phases
(quartz, K-feldspar, plagioclase, biotite, amphibole, titanite,
ilmenite, magnetite) plus melt and vapour (Hammastrom &
Zen,1986; Hollisteret al.,1987), amphibole Alt canbe used as a
geobarometer. Estimated pressures using various calibrations (Hammastrom & Zen, 1986; Hollister et al., 1987;
Johnson & Rutherford, 1989; Schmidt, 1992; Anderson &
Smith, 1995) are in the range of 7^5 kbar for lamprophyres,
3^1kbar for hybrid quartz diorites^granodiorites and 6^
4 kbar for the composite dyke. However, the estimated composite-dyke pressures may be questionable as their amphiboles are iron-rich and the barometers are calibrated for
Mg/(Fe þ Mg)4035 (Anderson & Smith,1995).
Accessory minerals
Apatite, zircon, allanite, titanite, magnetite, ilmenite
and monazite are the most common accessory minerals,
362
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Table 4: Representative analyses of biotites
EQU-2
EQU-6
POR-1
POR-5
HYB-2
HYB-4
COM-4
SiO2
3548
3154
3607
3614
3595
3607
3538
TiO2
402
231
419
414
402
305
374
Al2O3
1311
1459
1318
1326
1325
1418
1316
FeO
2655
3107
2466
2373
2274
2504
2563
MnO
066
053
033
028
029
037
042
MgO
634
727
814
810
919
706
702
Na2O
004
001
012
009
005
003
007
wt %
K2O
931
520
942
941
943
960
931
9551
9252
9611
9515
9492
9540
9473
Si
564
522
563
567
563
568
564
AlIV
236
278
237
233
237
232
236
(Z)
800
800
800
800
800
800
800
AlVI
009
006
006
012
008
031
012
Ti
048
029
049
049
047
036
045
Fe
353
430
322
311
298
330
342
Mn
009
007
004
004
004
005
006
Mg
150
179
189
190
215
166
167
(Y)
569
651
57
566
572
568
572
Na
001
000
004
003
002
001
002
K
189
110
188
188
189
193
189
(X)
19
11
192
191
191
194
191
1559
1561
1562
1557
1563
1562
1563
070
071
063
062
058
067
067
(cat)
Fe/(Mg þ Fe)
and occur in all facies. The growth textures and composition of apatite, zircon and allanite shed light on the evolution of the host magmas.
Apatite
Fig. 3. Variation of Ti (a.p.f.u.) vs Fe/(Fe þ Mg) (a.p.f.u.) for biotites
and amphiboles of the Karkonosze granite.
Long prismatic^acicular apatites and stubby apatites occur
in the porphyritic granite, hybrid rocks and lamprophyres.
Equant crystals occur only in the equigranular granite. In
both cases, crystals are zoned mostly in LREE, Y and Mn
contents (Table 6) (Saby & Go«tze, 2004).
In the equigranular granite, apatite is regularly zoned
(oscillatory) with Y contents increasing from core
(7900 ppm) to rim (11540 ppm) whereas the LREE contents remain relatively low. In the hybrid quartz diorites^
granodiorites and in the porphyritic granite, the zoning is
mostly irregular and discontinuous with multiple resorptions. Zones are alternately REE-rich and REE-poor.
These apatite crystals are richer in LREE than those in
the equigranular granite, but significantly poorer in Y
(1200 ppm). In composite dykes, stubby crystals have
irregular shapes with deep dissolution embayments.
363
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Table 5: Representative analyses of amphiboles
HYB-2a
HYB-2b
HYB-4
COM-1a
COM-1b
LAM-4a
LAM-4b
SiO2
4717
4592
4717
4063
4166
4262
4281
TiO2
099
138
094
190
175
230
254
Al2O3
599
649
602
908
860
1195
1049
FeO
1969
2079
1891
2691
2647
885
1191
MnO
058
053
050
065
067
011
021
MgO
993
885
999
439
465
1577
1429
CaO
1145
1151
1174
1084
1089
1168
1190
Na2O
109
127
087
195
187
224
210
K2O
060
077
055
126
118
112
076
9749
9751
9669
9761
9774
9664
9701
wt %
Si
707
697
712
641
655
620
629
AlIV
093
103
088
159
145
180
171
(T)
800
800
800
800
800
800
800
AlVI
013
013
019
010
014
024
010
Ti
011
016
011
022
021
025
028
Fe3þ
047
032
031
052
043
058
057
Fe2þ
200
232
208
304
305
049
090
Mn
007
007
006
009
009
001
003
Mg
222
200
225
103
109
342
313
(C)
500
500
500
500
500
500
500
Ca
184
187
190
183
183
182
187
Na
016
013
010
017
017
018
013
(B)
200
200
200
200
200
200
200
Na
016
025
015
043
040
045
047
K
011
015
011
025
024
021
014
(A)
027
039
026
068
064
066
061
(cat)
1527
1539
1526
1568
1564
1566
1561
053
046
052
025
026
087
078
Mg/(Mg þ Fe)
Some crystals display sieve textures. All have high
(515 000 ppm) Y contents, and a contrasting, bimodal
LREE distribution. The apatite growth textures and zone
compositions reflect growth in a magma mixing regime
during formation of the porphyritic and hybrid rocks
(Saby & Go«tze, 2004), as well as progressive closedsystem behaviour in the equigranular granite (Przywo¤ski,
2006; Saby et al., 2007b).
Zircon
Zircon occurs as single grains in the equigranular and porphyritic granites and in the hybrids. In composite dykes,
zircon forms complex clusters of crystals with skeletal morphology. Cathodoluminescence and BSE images reveal
flame-like magmatic zoning and point to the lack of any
inherited cores, although these have been previously
reported in the Karkonosze granite (Kryza et al., 1979).
Zircons from the composite dykes and from the more silicic
equigranular granites are zoned, with strong rimward
enrichments in Y, Th and heavy REE (HREE) (Table 7).
Allanite
Zoned allanite crystals occur in the granite and composite
dykes. Zoning patterns are complex with, in some cases,
discordant sector zoning repeatedly separated by oscillatory zoning. All crystals are allanite-(Ce), with LREErich and Th-, Fe-, Ti-poor cores and with rims relatively
poor in LREE and rich in Th, Fe and Ti (Table 8). Y contents are low in both cores and rims.
W H O L E - RO C K G E O C H E M I S T RY
Whole-rock major- and trace-element compositions for the
various rock types are given in Tables 9^13.
364
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Table 6: Representative analyses of apatites
EQU-12 core
EQU-12 rim
POR-1 core
POR-5 rim
POR-14 core
HYB-5 core
HYB-5 rim
COM-3 core
COM-3 rim
wt %
SiO2
019
117
048
083
048
025
027
069
071
FeO
004
010
006
005
006
002
5001
005
003
MnO
003
006
011
022
011
041
015
011
013
MgO
001
5001
5001
5001
5001
5001
5001
001
002
CaO
5487
5355
5499
5346
5499
5393
5431
5363
5366
SrO
5001
5001
5001
5001
5001
5001
5001
5001
5001
Na2O
007
004
004
015
004
017
006
011
015
P2O5
P
4241
4023
4262
4104
4262
4223
4218
4115
4179
976
9515
983
9574
983
9702
9697
9575
9649
ppm
Y
7900
11540
928
3973
2992
1167
1126
10110
14950
Nd
2220
2745
1238
5232
3870
1496
1753
2020
2850
Pr
400
430
509
482
1619
–
1096
–
520
Ce
1910
1899
1807
5566
3643
1576
1454
2390
3080
La
580
700
579
1495
1343
728
329
270
730
Table 7: Representative analyses of zircons
EQU-12 core
EQU-12 rim
EQU-12 rim
POR-1 core
POR-1 rim
POR-1 rim
COM-1 core
COM-3 core
COM-3 rim
wt %
SiO2
3250
3267
3143
3262
3244
3214
3151
3088
3145
ZrO2
6697
6652
6243
6622
6691
6568
6451
6212
6384
HfO2
110
152
189
162
144
109
117
108
108
Sc2O3
001
001
001
001
5001
002
002
002
001
FeO
009
004
5001
010
005
008
006
035
007
P2O5
P
003
5001
026
005
002
014
013
020
017
10070
10076
9602
10062
10086
9915
9740
9465
9662
ppm
Y
1630
440
20290
980
1870
3710
5101
12043
U
450
430
7100
1120
1980
5200
5221
5583
6103
Th
270
170
3380
230
1070
2850
5612
7655
10299
Yb
670
340
4060
540
670
1080
1298
2419
2753
Er
590
630
3250
510
650
720
1032
1957
2078
Ho
–
220
340
–
180
–
241
78
430
Dy
220
120
1680
190
310
690
623
231
502
Equigranular and porphyritic granites
The very homogeneous equigranular granite is SiO2-rich
(7301^7787 wt %) with low Mg-number [atomic Mg/
(Mg þ Fe)] values of 011^038 (Table 9). In the
12421
(Na2O þ K2O) vs SiO2 diagram (Fig. 4a), it plots in the
upper part of the sub-alkaline field of Rickwood (1989).
The Na2O/K2O ratio is low (51), a result of the K2O-rich
(433^610%) character of rocks that plot in the high-K
365
JOURNAL OF PETROLOGY
VOLUME 49
Table 8: Representative analyses of allanite
COM-1 core
COM-1 rim
wt %
SiO2
3254
1838
TiO2
170
421
ThO2
135
325
Al2O3
1273
1667
Y2O3
012
007
La2O3
608
167
Ce2O3
1222
389
Pr2O3
105
036
Nd2O3
332
111
Sm2O3
029
012
Gd2O3
004
004
Tb2O3
001
5001
Dy2O3
012
007
1374
2805
MgO
044
019
CaO
1150
253
Na2O
005
032
FeO
K2O
P
5001
056
9730
8149
calc-alkaline field of the K2O vs SiO2 diagram (Fig. 4b).
The equigranular granite is mostly peraluminous, with
A/CNK [Al2O3/(CaO þ Na2O þ K2O)] ranging from
098 to 114 (Fig. 4c, Table 9). The porphyritic granite has
the same characteristics except that it ranges towards
lower SiO2 contents (6927%) and higher Mg-number
(047) (Tables 10 and 11). Some samples are significantly
poorer in K2O than the equigranular granite and plot in
the medium-K calc-alkaline field (Fig. 4b).
In the CIPW normative An^Ab^Or classification diagram, the equigranular granite plots in the granitic field,
whereas the porphyritic types may extend towards the
granodiorite field (Fig. 5a). The Q^Ab^Or triangular diagram (Fig. 5b) shows that the equigranular granite has a
composition close to the minima on the quartz^feldspar
cotectics in the ‘hydrous granitic system’ for pressures ranging between 1 and 2 kbar (Fig. 5b). This is consistent with
the pressure deduced from the amphibole compositions.
Some of the porphyritic rocks plot together with the equigranular rocks, whereas others plot below the cotectic and
do not display eutectic-like compositions.
On Harker diagrams (Fig. 6), all elements except for
K2O correlate negatively with SiO2. In most cases the
data for both equigranular and porphyritic facies plot on
more or less the same trend. However, in (Na2O þ K2O)
NUMBER 2
FEBRUARY 2008
/CaO vs Al2O3 and (MgO/Fe2O3) vs SiO2 plots (Fig. 7),
the equigranular granite follows a differentiation trend,
whereas the porphyritic granite (particularly SiO2-poor
samples) deviates markedly.
The equigranular granite REE patterns (Fig. 8a) show
variable LREE (1154LaN419), high and variable HREE
(254YbN412) and strong Eu anomalies (0384Eu/
Eu4011); Eu/Eu ¼ EuN/[(SmN þ GdN)/2)]. The porphyritic granite (Fig. 8b) shows similar REE patterns,
although the LREE (1964LaN431) are somewhat higher
than in the equigranular granite; Eu anomalies are also
strongly negative (0694Eu/Eu4018). The LaN vs SiO2
diagram (Fig. 9a) shows that these two elements are
strongly anti-correlated in the equigranular graniteçand
also in the more silicic (SiO24 71%) porphyritic granites; such a correlation is absent in the less silicic porphyritic granites. The decrease in La (and other LREE) with
progressive differentiation points to the fractionation of
mineral=liquid
mineral phase(s) with KdLa
1. In contrast, Yb
is not correlated with SiO2 (Fig. 9b), indicating that the
crystallizing phases had a bulk partition coefficient D 1
mineral=liquid
and, thus, that the mineral phase with KdLa
1
mineral=liquid
had significantly lower KdYb
.
Primitive mantle-normalized, multi-element diagrams
(Sun & McDonough, 1989; Fig. 10) show that both
equigranular and porphyritic granites are strongly
enriched in LILE. Both show negative anomalies (Ba, Nb,
Sr, P, Eu, Ti), which are clearly more pronounced in the
equigranular granite.
The significance of these anomalies can be investigated
using element ratio vs SiO2 diagrams (Fig. 11). The (Ba/
Rb)N diagram (Fig. 11a) shows that the negative Ba anomaly increases during the course of differentiationçimplying the fractionation of phases such as K-feldspar and
mineral=liquid
biotite with KdBa
1. However the fractionation
of these minerals should also deplete the melt in both K
and Rb (behaving as a compatible element in Karkonosze
alkali feldspars; E. Saby, unpublished data), which is
obviously not the case in the Karkonosze granite (Fig. 6).
Kfeldspar=liquid
It must be noted that KdRb
41 has been
reported for natural rhyolites (Nash & Crecraft, 1985) as
well as for experimental leucosomes (Bea et al., 1994).
plagioclase=matrix
Streck & Grunder (1997) obtained KdBa
ranging between 6 and 19 in high-Si rhyolites and Icenhower &
plagioclase=melt
London (1996) measured KdBa
between 11 and
18 in experimental granitic melts. These results show that
in melts such as those from which the equigranular granite
crystallized, not only K-feldspar and biotite are able to significantly fractionate Ba, but plagioclase also.
Both (Sr/Ce)N (Fig. 11c) and (Eu/Gd)N (Fig. 11f) show
that the Sr and Eu negative anomalies also increase with
differentiation, although some porphyritic granites deviate
from the trend defined by the rest of the data. On the other
hand, the strong correlation of Sr with Eu (Fig. 11h) may
366
Table 9: Major and trace element analyses of equigranular granites
EQU-1
EQU-2
EQU-3
EQU-4
EQU-5
EQU-6
EQU-7
EQU-8
EQU-9
EQU-10
EQU-11
EQU-12
EQU-13
EQU-14
EQU-15
SiO2
7301
7470
7555
7577
7594
7657
7672
7688
7700
7702
7703
7737
7763
7771
7787
TiO2
030
035
016
022
017
015
011
019
016
007
004
007
007
015
012
Al2O3
1402
1310
1336
1283
1320
1321
1273
1252
1256
1294
1296
1274
1269
1222
1195
wt %
221
117
180
128
104
119
152
134
089
026
072
079
127
100
004
005
003
004
005
003
003
003
005
002
001
002
002
004
003
MgO
044
054
023
028
027
032
015
018
020
008
002
008
005
020
014
CaO
183
062
058
103
091
055
049
068
070
048
055
067
037
062
074
Na2O
379
311
334
317
344
320
344
288
335
290
298
348
313
327
318
K2O
433
521
550
480
467
490
513
507
459
560
610
484
524
446
494
P2O5
009
010
008
006
005
003
002
005
005
001
005
001
001
004
003
A/CNK
098
110
107
104
107
114
105
109
107
110
103
104
110
108
100
Mg-no.
029
033
028
024
030
038
020
019
023
015
013
018
011
024
021
ppm
367
Rb
250
316
297
265
307
304
374
257
301
373
236
277
297
307
301
Ba
230
326
192
215
137
102
15
199
84
18
123
40
36
70
91
371
325
249
35
Th
288
204
288
294
332
285
Nb
13
17
12
Sr
85
111
Zr
156
Y
37
11
17
16
12
10
11
16
3
16
9
9
6
46
55
48
41
32
47
27
11
31
15
15
35
30
125
85
137
84
95
99
108
112
62
14
54
86
103
87
28
26
39
42
34
49
26
35
89
17
42
30
54
43
11
12
17
10
15
5
7
6
12
12
6
99
94
Ni
24
48
La
361
238
236
Ce
757
47
Nd
316
231
Sm
58
48
47
Eu
046
056
Gd
533
Dy
05
284
17
06
165
142
178
13
502
416
332
402
282
145
238
231
219
20
155
185
194
63
139
97
51
41
49
44
16
39
23
035
029
026
021
017
016
017
014
401
415
511
367
563
471
196
439
272
554
427
39
766
472
834
584
26
591
44
Er
357
268
249
492
309
506
434
195
393
316
Yb
323
296
31
486
398
512
474
26
486
347
Lu
049
04
039
069
052
085
071
033
074
054
(La/Yb)N
68
60
64
23
31
24
20
21
17
20
Eu/Eu
025
038
024
017
020
012
011
028
013
017
375
MAGMA INTERACTION, KARKONOSZE PLUTON
215
SLABY AND MARTIN
Fe2O3t
MnO
Table 10: Major and trace element analyses of porphyritic granites
POR-1
POR-2
POR-3
POR-4
POR-5
POR-6
POR-7
POR-8
POR-9
POR-10
POR-11
POR-12
POR-13
POR-14
POR-15
SiO2
6927
6927
6965
6968
6992
7011
7015
7160
7180
7182
7210
7216
7222
7234
TiO2
059
063
058
046
049
047
045
041
033
050
056
032
038
040
025
Al2O3
1503
1498
1467
1525
1507
1508
1511
1421
1490
1414
1344
1458
1409
1411
1459
Fe2O3t
352
428
379
295
298
279
278
292
228
314
392
221
284
244
200
MnO
006
010
007
005
005
005
005
006
004
006
006
003
005
005
004
MgO
125
119
107
100
090
096
097
060
070
097
108
049
062
085
033
CaO
271
250
207
190
210
224
231
160
198
204
199
138
159
193
141
Na2O
341
387
332
338
348
351
356
339
392
350
378
328
328
345
358
wt %
7241
400
291
459
520
483
464
449
511
395
367
288
545
481
431
531
P2O5
016
026
019
014
017
014
012
011
011
015
017
010
012
012
007
A/CNK
101
107
103
104
102
101
101
101
104
105
104
105
104
102
103
Mg-no.
041
035
036
040
037
041
041
029
038
038
035
030
030
041
025
JOURNAL OF PETROLOGY
K2O
ppm
260
224
224
229
207
214
238
248
199
279
252
243
234
427
302
631
892
790
887
701
449
454
407
252
608
554
422
Th
24
405
228
177
222
229
241
177
74
257
239
194
202
207
Nb
17
22
15
15
16
14
15
11
8
12
15
13
11
10
Sr
221
138
166
199
202
211
216
100
130
153
105
134
131
146
Zr
204
257
228
178
206
192
158
203
138
203
235
158
184
152
Y
43
57
37
51
48
48
48
38
21
40
32
58
53
29
26
17
69
18
11
21
10
85
68
57
La
509
618
Ce
892
Nd
356
Sm
6
364
259
489
426
35
136
463
1408
823
496
972
816
749
297
1002
535
323
221
384
326
278
24
147
34
66
49
69
55
58
086
46
Eu
103
61
078
099
107
121
091
076
072
Gd
073
542
98
64
446
543
472
537
596
554
Dy
522
973
587
482
487
504
571
622
434
Er
278
565
349
288
289
241
305
4
281
Yb
317
628
364
32
259
291
319
396
291
Lu
04
076
047
049
037
045
037
054
124
74
71
61
78
23
023
046
069
041
042
(La/Yb)N
Eu/Eu
055
11
114
059
72
120
054
24
28
25
041
111
038
FEBRUARY 2008
Ni
NUMBER 2
167
Ba
VOLUME 49
368
Rb
Table 11: Major and trace element analyses of porphyritic granites and lamprophyres
Porphyritic granite
Lamprophyre
POR-18
POR-19
POR-20
POR-21
POR-22
POR-23
POR-24
POR-25
POR-26
LAM-1
SiO2
7263
7325
7336
7373
7401
7458
7516
7562
7565
7585
7748
4965
TiO2
049
030
029
035
037
037
027
026
021
023
008
223
Al2O3
1374
1439
1392
1392
1322
1308
1281
1268
1325
1293
1266
Fe2O3t
329
197
210
244
237
249
214
209
121
139
MnO
007
005
004
004
005
003
004
004
003
005
MgO
094
068
047
076
077
072
031
033
054
CaO
187
104
136
161
140
112
123
121
Na2O
338
349
324
375
308
329
307
K2O
340
473
512
329
462
421
P2O5
020
009
010
011
010
011
A/CNK
109
113
104
110
105
Mg-no.
036
040
031
038
039
LAM-2
LAM-3
LAM-4
5135
5280
5813
201
167
092
1747
1623
1673
1705
074
1147
907
1074
667
002
016
–
015
014
052
003
601
671
483
449
071
081
073
547
593
634
457
299
282
284
327
258
394
401
390
488
470
553
531
498
386
397
234
377
007
007
006
007
001
109
078
037
036
109
102
104
111
109
105
095
075
081
091
036
022
024
047
043
007
051
059
047
057
wt %
369
ppm
Rb
231
221
250
231
226
246
243
247
222
253
190
146
137
132
Ba
541
368
405
341
362
457
286
185
246
231
9
942
806
1135
219
319
25
127
13
12
11
12
15
81
Th
287
182
208
Nb
17
13
13
8
332
15
295
9
Sr
139
129
98
127
110
115
66
57
86
63
17
1221
407
821
Zr
205
118
155
138
148
132
156
178
78
95
56
372
189
182
Y
45
49
43
19
30
19
42
38
24
22
31
41
45
26
Ni
17
5
14
7
17
11
10
8
13
9
10
1054
268
94
La
47
249
332
36
264
114
218
955
441
545
Ce
999
496
655
821
449
26
52
236
1884
775
989
Nd
381
225
315
314
201
117
198
116
804
383
407
Sm
6
42
63
61
48
29
45
324
134
71
61
Eu
084
062
074
062
084
051
043
019
279
195
15
Gd
709
386
552
495
467
306
413
320
964
681
377
Dy
703
383
663
43
4
333
375
438
602
644
345
Er
411
229
397
249
239
221
225
298
33
357
164
Yb
428
257
448
304
236
258
27
383
345
298
166
Lu
057
04
067
038
033
035
034
059
057
049
(La/Yb)N
77
74
57
98
75
35
66
22
Eu/Eu
040
047
038
034
054
052
030
018
970
196
072
79
18
84
085
115
14
022
225
090
MAGMA INTERACTION, KARKONOSZE PLUTON
POR-17
SLABY AND MARTIN
POR-16
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Table 12: Major and trace element analyses of hybrid quartz diorites and granodiorites
HYB-1
HYB-2
HYB-3
HYB-4
HYB-5
HYB-6
HYB-7
HYB-8
HYB-9
HYB-10
HYB-11
HYB-12
SiO2
5299
5858
6117
6232
6295
6319
6331
6344
6664
6924
7027
TiO2
184
155
135
125
108
113
109
106
088
060
058
046
Al2O3
1654
1552
1537
1553
1622
1511
1559
1608
1482
1458
1409
1429
Fe2O3t
wt %
7094
1153
875
707
650
577
640
611
583
513
396
369
324
MnO
020
016
011
010
008
010
010
009
009
006
007
006
MgO
435
320
322
302
220
291
253
214
213
118
112
104
CaO
561
496
494
447
413
391
392
394
343
250
243
206
Na2O
390
388
345
362
370
350
353
355
365
358
336
335
K2O
269
310
304
292
347
352
350
346
306
416
427
447
P2O5
035
030
027
027
041
022
032
042
018
013
013
011
A/CNK
085
083
086
090
093
090
093
096
095
097
097
101
Mg-no.
043
042
047
048
043
047
045
042
045
037
037
039
ppm
Rb
292
257
185
194
145
158
201
231
134
Ba
132
485
490
410
967
859
371
408
418
Th
13
115
123
177
172
21
182
251
266
Nb
24
17
10
15
13
14
16
19
14
Sr
132
137
274
234
286
273
193
150
237
Zr
196
199
199
190
305
371
225
171
177
Y
53
56
49
55
37
33
57
62
60
Ni
177
173
258
334
252
350
267
48
240
La
313
32
289
489
317
387
414
395
Ce
347
657
707
987
706
790
825
817
Nd
287
328
321
510
347
370
350
377
Sm
62
68
67
83
74
72
73
74
Eu
088
135
129
157
145
113
091
085
Gd
564
609
600
676
627
662
644
685
Dy
541
622
614
565
551
683
609
748
Er
301
326
357
284
289
368
362
422
Yb
317
289
346
271
279
36
352
419
Lu
050
045
049
040
049
055
05
064
(La/Yb)N
70
66
55
74
71
77
63
Eu/Eu
045
063
062
064
050
040
036
116
063
be interpreted as demonstrating control by a single phase.
In granitic magmas, only feldspars have both Kdmineral=melt
Sr
and Kdmineral=melt
41, but as K and Rb increase during difEu
ferentiation, this phase must have been plagioclase. The
good correlation between Ba and Sr (Fig. 11i) also favours
plagioclase fractionation controlling Sr, Eu and Ba.
The (P/Nd)N plot (Fig. 11d) reveals the role of a
P-bearing phase that could have been apatite. However, a
correlation between this ratio and SiO2 exists only for
rocks with SiO2474% (mainly equigranular granite).
Early apatite evidently attained only localized saturation
(Hoskin et al., 2000) rather than late saturation appearing
during the last stages of differentiation. Similarly, the
(Ti/Gd)N diagram (Fig. 11g) points to the fractionation of
a Ti-rich phase that could be ilmenite and/or Ti-rich magnetite or biotite.
(Zr/Sm)N behaviour (Fig. 11e) is slightly different.
(Zr/Sm)N is correlated with SiO2; in the less differentiated
rocks it is 41 (positive anomaly) whereas it is 51 (negative
anomaly) in the more differentiated rocks (Fig. 11e).
370
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Table 13: Major and trace element analyses of microgranular magmatic enclaves (MME) and composite dykes
Microgranular magmatic enclaves
Composite dykes
MME-1
MME-2
MME-3
MME-4
MME-5
MME-6
COM-1
COM-2
COM-3
COM-4
COM-5
COM-6
SiO2
6433
6824
6908
6913
6924
6977
6233
6742
6777
6847
6867
6946
TiO2
081
066
056
067
058
056
093
053
052
051
055
042
Al2O3
1686
1569
1544
1501
1563
1485
1776
1619
1586
1555
1532
1594
wt %
Fe2O3t
547
408
340
417
373
378
639
405
406
402
361
277
MnO
013
009
007
009
009
007
006
005
005
005
006
005
MgO
182
142
122
138
121
085
124
069
068
056
078
052
CaO
254
304
267
275
326
156
180
204
204
182
169
164
Na2O
584
457
418
447
459
345
491
386
388
396
349
447
K2O
198
202
324
210
153
499
412
502
499
489
571
463
P2O5
021
020
015
022
014
013
046
014
014
016
013
009
A/CNK
103
103
101
103
103
107
112
104
102
103
102
104
Mg-no.
040
041
042
040
039
031
028
025
025
022
030
027
ppm
Rb
271
241
263
247
219
337
357
282
285
270
348
281
Ba
230
220
550
226
300
465
400
911
931
831
480
774
Th
107
196
135
201
132
213
223
237
229
213
255
28
Nb
45
26
16
23
34
17
49
17
17
17
18
23
Sr
106
138
160
116
174
95
92
189
193
194
103
140
Zr
321
213
188
238
163
286
502
377
359
359
372
506
Y
80
63
54
58
50
81
149
38
39
44
103
35
Ni
133
83
53
94
47
34
38
22
13
17
25
14
La
97
387
218
269
208
126
396
664
663
657
1017
640
Ce
191
724
404
490
413
276
747
113
Nd
119
312
197
215
188
151
379
48
Sm
45
70
44
36
49
47
118
Eu
045
059
060
088
057
066
Gd
542
615
41
312
454
Dy
75
562
405
28
Er
476
318
24
Yb
626
302
Lu
09
(La/Yb)N
Eu/Eu
112
112
170
351
83
85
77
059
151
146
142
103
100
578
1277
673
692
639
1153
558
498
721
1565
643
648
685
1031
556
152
299
421
1039
353
356
416
546
346
241
151
336
400
1101
360
365
450
484
390
042
038
025
050
060
162
052
050
064
066
14
82
61
47
20
26
028
027
043
037
039
015
120
079
The rather good correlation shows that zircon fractionated, but the values 41 in less differentiated rocks show
that the parental magma already had a small positive Zr
anomaly that turned negative during fractionation.
Unlike other element ratios, (Nb/K)N (Fig. 11b) is not
correlated with SiO2 even though a pronounced Nb anomaly is evident in the primitive mantle multi-element diagrams (Fig. 10). The lack of correlation with SiO2
127
060
126
057
107
061
73
123
481
139
126
024
434
74
057
125
046
indicates that the negative Nb anomaly was inherited
from source melting and does not reflect later
differentiation.
Geochemical modelling of granite differentiation
Several lines of evidence, presented above, indicate that
fractional crystallization occurred in both porphyritic and
equigranular granites. The schlieren, and internal feldspar
371
JOURNAL OF PETROLOGY
VOLUME 49
Fig. 4. (a) (K2O þ Na2O) vs SiO2 showing the sub-alkaline character of both equigranular and porphyritic granites. The lower dashed
line is from Kuno (1966) and the upper continuous line from Irvine &
Baragar (1971); (b) K2O vs SiO2 (Rickwood, 1989) demonstrating the
high-K calc-alkaline affinity of the Karkonosze granite; (c) Al2O3/
(Na2O þ K2O) vs Al2O3/(CaO þ Na2O þ K2O) molar diagram
(Shand, 1943), showing the slightly peraluminous character of the
equigranular and porphyritic granites.
segregation, for example, could reflect fractional crystallization in a dynamic flow regime. Although crystal separation was not perfect, multiphase flow resulted in zones
enriched in cumulus phases and differentiated liquid,
respectively. Mass-balance calculations allow the total
amount of cumulate removed to be determined, irrespective of the exact physical process invoked. Initially, the
process is modelled using mass-balance calculations based
only on major elements (Sto«rmer & Nicholls, 1978) to yield
the modal and chemical compositions of the cumulate and
the degree of fractional crystallization. In the second step,
these computed values are entered into trace-element
models using the equations of Rayleigh (1896).
Both major and trace elements define linear differentiation trends for the equigranular granites and the more
NUMBER 2
FEBRUARY 2008
silicic porphyritic granites (SiO2472%). Consequently,
modelling of the fractional crystallization process was performed to try to explain the differentiation of high-Si melts
(78%) from those with lower Si contents (72%). The compositions used in the mass-balance calculations were computed from the correlation lines in the Harker diagrams
(Fig. 6); these, and the mineral compositions used in modelling, are given in Table 14, where the results are also
shown. The cumulate assemblage that best fits the data
comprises 6246% plagioclase þ 3046% biotite þ 466%
magnetite þ 23% apatite þ 012% ilmenite. The low
(007) sum of squared residuals testifies to the goodness of
fit. The amount of fractional crystallization is low (18%).
There is a very good correlation between the size of the
negative Ti anomaly and the degree of differentiation
(Fig. 11g). The amount of ilmenite in the cumulate is very
low (012%), probably because in the Karkonosze granite
both biotite and magnetite are Ti-rich (TiO2 43% and
813%, respectively); consequently, Ti fractionation was
almost totally controlled by these phases. All the computed
models preclude fractionation of significant K-feldspar
(always 52%). The best fit between model and data is
obtained with K-feldspar-free cumulates. If K-feldspars
crystallized, they were not removed from the magma.
Trace-element modelling was based on mineral/liquid
partition coefficients (Kdm/l) for rhyolites and high-silica
rhyolites; the chosen values are given in Table 15. Sample
POR-1 (SiO2 7263%) was chosen as representative of the
parental magma and sample EQU-12 (SiO2 7737%) as
representative of the daughter magma. When the cumulate
composition and the degree of fractionation calculated
from the major-element data are used in trace-element
modelling, the models do not appear to fit the analytical
data at all. This is particularly obvious for LREE where
the modelled magma has 40 ppm La whereas sample
EQU-12 has only 99 ppm La (Fig. 12a). Similarly, modelling predicts the incompatible behaviour of Zr (Fig. 13a)
whereas in the Karkonosze granite, Zr decreases from
204 ppm in POR-1 to 54 ppm in EQU-12, indicating
strongly compatible behaviour (Fig. 11e). These differences
are easily resolved. Only a small amount (012%) of zircon
is needed to explain Zr abundances in the evolved magma.
Both allanite and monazite can strongly fractionate the
LREE without significantly modifying the HREE.
As monazite also fractionates P, significantly reducing the
amount of cumulative apatite, REE and P behaviour could
reflect either monazite or allanite þ apatite fractionation.
The latter seems more likely. First, unlike monazite,
allanite is abundant in the Karkonosze granite. Second,
the slight impoverishment of middle REE (MREE) relative to LREE and HREE in the differentiated magma
is
consistent
with
apatite
fractionation with
apatite=melt
apatite=melt
apatite=melt
KdMREE
4KdLREE
KdHREE
. Also, the calculated amount of allanite is low (027%).
372
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Fig. 5. (a) CIPW normative An^Ab^Or triangle (O’Connor, 1965); with fields from Barker (1979). To, tonalite; Tdh, trondhjemite; Gd, granodiorite; Gr, granite. (b) CIPW normative Q^Ab^Or triangle, showing that the equigranular granite as well as some more evolved porphyritic
varieties plot near the minimum melt point of the ‘hydrous granitic system’ for pressures ranging between 1 and 2 kbar. Compositions of SiO2rich rocks (473%) were corrected following Blundy & Cashman (2001).
(Fig. 11b). Only Eu does not fit the analytical data. The
models predict the development of a less pronounced negative Eu anomaly than that characterizing the rocks.
Plagioclase is the main phase capable of inducing a negative Eu anomaly in melts. Low fO2 would strongly favour
plagioclase=melt
. However, ilmenite þ magnetite in
high KdEu
the mineral association in the Karkonosze granite and in
the computed cumulate would rather argue for a high fO2 .
plagioclase=melt
(9) in rhyolitic magmas has
A very high KdEu
been already reported by Nash & Crecraft (1985).
In conclusion, modelling, based on both major and trace
elements, shows that the composition of the more silicic
equigranular granites in Karkonosze can reasonably be
accounted for by about 18% fractional crystallization of a
plagioclase þ biotite þ accessories (apatite, magnetite,
ilmenite, zircon, allanite) cumulate from a parental
magma with 72% SiO2.
Hybrid rocks and lamprophyre
Hybrid quartz diorites^granodiorites and lamprophyre dykes
Fig. 6. Variation of Al2O3, MgO, Na2O, TiO2, Fe2O3t, CaO, K2O
and P2O5 vs SiO2 (wt %) for the equigranular and porphyritic
granites.
The introduction of these two accessory phases into the
modelling allows perfect agreement between the computed
composition and the composition of EQU-12 for both REE
and other trace elements (Figs 12b and 13b).
The models do not predict any significant modification
of the negative Nb anomaly in the Karkonosze rocks
The SiO2 contents of the hybrid quartz diorites^granodiorites, mostly from Fojtka and Rudolfov near Liberec,
Czech Republic (Fig. 1b), range between 53 and 71% and
Mg-number varies in the narrow range 037^048
(Table 12). They are K2O-rich (269^447%) with
Na2O/K2O ranging from 145 to 075, anti-correlated with
SiO2 content. They are metaluminous with A/CNK ranging from 083 to 101 (Fig. 14a, Table 12).
Lamprophyres occur as syn-kinematic dykes. They are
commonly weathered, which could explain the relative
scatter in their chemical composition, although the analysed samples showed no visible effects of alteration in the
field or in thin section. The least differentiated types have
SiO2 of 4965% (Table 11). Mg-number ranges from 059 to
047, K2O is 437% and Na2O/K2O 1 except for LAM-3
(K2O 234% and Na2O/K2O ¼17). A/CNK varies
in the range 075^095 as in the hybrid quartz
373
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Fig. 7. (a) (Na2O þ K2O)/CaO vs Al2O3 and (b) (MgO/Fe2O3) vs SiO2 (wt %)
Fig. 8. Chondrite-normalized REE patterns for the equigranular (a) and porphyritic (b) granites. Normalization values are from Masuda et al.
(1973) divided by 12.
Fig. 9. (a) LaN vs SiO2, showing that these two elements are negatively correlated in the equigranular granite and in the more silicic
(SiO2471%) porphyritic granites; the less silicic granites deviate from this correlation. (b) YbN vs SiO2, indicating that, unlike La, Yb is not
correlated with SiO2.
diorites^granodiorites (Fig. 14a, Table 11). The hybrid
quartz diorites^granodiorites define a linear trend linking
the equigranular granite and the lamprophyres (Fig. 14a).
The lamprophyre and hybrid fields overlap extensively
with the more mafic porphyritic granites, showing a
similar, if less pronounced, link with the lamprophyres.
The same observation can be drawn from Fig. 14b: if the
equigranular granite has a composition close to the minimum on the cotectics of the ‘hydrous granitic system’ for
pressures between 1 and 2 kbar, all hybrids and some of
the porphyritic rocks plotting far below the cotectics
define a linear trend towards the lamprophyres. This
trend cannot be accounted for by melting or crystallization
processes. Mixing is indicated.
374
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Fig. 10. Primitive mantle-normalized multi-element diagrams for both equigranular (a) and porphyritic (b) granites. Normalization constants
from Sun & McDonough (1989).
Similar correlations are seen in major element Harker
diagrams (Fig. 15). Even in the K2O vs SiO2 plot where
the granite data scatter, the hybrid quartz diorites^granodiorites define a coherent trend. The hybrid rocks, in systematically falling between the equigranular granite and
the lamprophyre compositions (Fig. 15), reinforce the
hypothesis that they resulted from mixing between
magmas with compositions similar to those of the
equigranular granite and the lamprophyres. The hybrid
quartz diorites^granodiorites define a continuous trend
indicating that end-member mixing occurred in all proportions. The low-SiO2 porphyritic granites display the
same trend towards the lamprophyre composition but, in
this case, mixed compositions are restricted to a field close
to that of the equigranular granites; the lamprophyre
volumes involved were low. At the present level of exposure, the granite is several orders of magnitude more voluminous than the lamprophyre in the dykes.
The REE patterns for hybrid quartz diorites^granodiorites (Fig.16a) are relatively homogeneous; theyare characterized by high LREE (1554LaN471) and high HREE
(244YbN413). The LREE are fractionated whereas the
HREE are almost flat. In addition, all patterns display a significant negative Eu anomaly (0644Eu/Eu4036). In contrast, the lamprophyres are richer in REE (Fig.16b); LaN can
be as high as 300; Awdankiewicz et al. (2005b) reported
LaN ¼ 230 in the Bukoviec lamprophyre near Jelenia Go¤ra.
Both LREE and HREE are similarly fractionated with no
or insignificant negative Eu anomalies (0904Eu/
Eu4072) at most. The primitive mantle-normalized
multi-element diagrams (Sun & McDonough, 1989;
Fig. 17a) corroborate the relatively restricted variability of
the hybrid quartz diorites^granodiorites. They show negative Ba, Nb, Sr, P, Eu and Ti anomalies as in the granite but
they are less marked.Two exceptional samples display significant positive Zr anomalies (Fig. 18e). The lamprophyres
375
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Fig. 11. Selected trace element ratios vs SiO2 or SrN; data are normalized to primitive mantle (Sun & McDonough, 1989).
Table 14: Major element composition for both parental and differentiated magmas
Parental
Differentiated
magma
magma
Biotite
Plagioclase
Apatite
Ilmenite
Magnetite
Cumulate
Computed
composition
differentiated
liquid
SiO2
7200
7800
3723
TiO2
04
01
433
Al2O3
1424
122
1340
Fe2O3t
28
08
2555
MgO
075
01
957
CaO
188
04
Na2O
325
34
K2O
45
50
P2O5
018
00
% of mineral phase in the cumulate:
—
008
984
5293
016
001
—
4440
7803
—
—
5067
813
176
010
3016
—
—
348
2308
1231
003
—
4918
8657
1189
081
—
—
004
182
300
026
1234
5648
010
—
901
032
447
—
—
—
282
334
007
—
—
—
304
482
4336
—
—
100
000
—
—
3046
6246
230
012
466
Mineral compositions from the Karkonosze granite were used for mass-balance modelling. The last line displays the modal
composition of the computed cumulate.
show regularly fractionated patterns (LILE-richer and
HREE-poorer) and, except for Nb, do not show any significant anomalies. The Nb anomaly characterizes only
two samples and is totally absent in the least differentiated
variety.
In all trace-element ratio vs SiO2 diagrams (Fig. 18a^i)
the hybrids plot on a trend connecting equigranular granites and lamprophyres. Comparison with the similar relationships shown by the major elements reinforces the
hypothesis of lamprophyre- and granite-magma mixing.
376
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Table 15: Partition coefficients used in fractional crystallization modelling
Kdmineral/liquid:
Plagioclase
Biotite
Ilmenite
Magnetite
Apatite
Allanite
Zircon
References:
1, 2
1, 3
1, 4
5, 6
7
3, 4
3
La
038
318
71
06
25
2595
2
Ce
0267
28
78
062
35
2278
264
Nd
0203
223
76
076
58
1620
22
Sm
0165
155
69
079
64
500
314
Eu
56
0867
25
056
30
111
Gd
0125
14
66
058
64
350
12
Dy
0112
0823
49
061
58
136
1015
Er
01
07
45
065
40
85
135
Yb
009
0537
41
069
22
245
264
Rb
0105
32
0001
0043
04
003
235
0001
01
05
0001
04
02
16
Ba
Th
Nb
Sr
10
0048
0997
006
6367
156
100
484
000001
01
012
0447
041
0093
24
078
01
013
Zr
0135
1197
5
024
Y
013
1233
031
321
40
20
314
0001
0001
221
100
0001
5900
71
Data sources: 1, Nash & Crecraft (1985); 2, Streck & Grunder (1997); 3, Mahood & Hildreth (1983); 4, Ewart & Griffin
(1994); 5, Brenan et al. (1998); 6, Bacon & Druitt (1988); 7, Pearce & Norry (1979).
Fig. 12. Chondrite-normalized REE patterns illustrating the results of fractional crystallization modelling (bold line). (a) Without allanite and
zircon; (b) when both allanite and zircon are taken into account. In both cases the degree of crystallization is 18%. The partition coefficients
used in the model are given in Table 15.
Figure 18a^g records element ratios that indicate the
importance of the anomalies observed in multi-element
plots (Fig. 17); the magnitude of Sr, P, Eu and Ti anomalies
(Fig. 18c, d, f and g) correlates with SiO2. Anomalies in Nb
and Zr remain constant. Thus, if mixing occurred, the prospective lamprophyre end-member might most probably
be lamprophyre characterized by a negative Nb anomaly
(Fig. 18b). Plotted against SiO2 (Fig. 18a), the Ba anomaly
shows no definable correlation.
Mixing in hybrid quartz diorites^granodiorites
In terms of both major- and trace-element compositions
(Figs 14 and 18), the hybrid quartz diorites^granodiorites
plot systematically between the lamprophyres and the
377
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Fig. 13. Primitive mantle-normalized trace element patterns illustrating the results of fractional crystallization modelling (bold line). (a)
Without allanite and zircon; (b) when both allanite and zircon are taken into account. In both case the degree of crystallization is 18%. The
partition coefficients used in the model are given in Table 15.
equigranular granites. For most elements, they also
define reasonable correlation lines, the only exceptions
being LILE (e.g. Rb, Sr and Ba). There is a clear
possibility that the latter elements were affected by
other processes; for example, local selective assimilation
or segregation of feldspars rich in Rb, Sr and Ba
(Saby et al., 2007a). In addition, in both hybrid quartz
diorites and granodiorites and the porphyritic granite,
mineral compositions and growth morphologies point to
crystallization coeval with magma mixing (Saby &
Go«tze, 2004; Saby et al., 2007a). Saby et al. (2007a,
2007b) used mineral^magma equilibria to calculate
magma compositions. In the Karkonosze hybrid quartz
diorites^granodiorites these compositions systematically
fall between those of lamprophyre and equigranular
granite.
A first attempt to test the hypothesis that the hybrid
quartz diorites^granodiorites resulted from the mixing of
lamprophyre and equigranular granite magmas is based
on major elements. The calculation uses an average
lamprophyre and the parental magma composition used
for the fractional crystallization modelling (Table 14).
The results for an average hybrid are given in a C(hybrid
quartz diorite^granodiorite) C(parental magma) vs C(lamprophyre) C(parental magma) diagram (Fig. 19a; Fourcade & Alle'gre,
1981), where C represents the concentration of an oxide. In
a case of mixing, all of the points on such a diagram would
plot on a straight line passing through the origin and with
a slope that represents the degree of mixing. The line
(R2 ¼ 0989) for the Karkonosze hybrid quartz diorites^
granodiorites, going exactly through the origin, supports
the mixing hypothesis and shows that an average hybrid
can be explained by the mixing of 44% lamprophyre and
56% granitic magma. For the less silicic porphyritic granite (sample POR-1), the line (R2 ¼ 0949) in Fig. 19b indicates about 15% contamination of the porphyritic granite
by lamprophyre.
The trace-element data, despite the relative scatter in
Rb, Sr and Ba, also strongly support mixing. The entire
range of compositions obtained by mixing between
378
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Fig. 14. (a) Al2O3/(Na2O þ K2O) vs Al2O3/(CaO þ Na2O þ K2O) molar diagram (Shand, 1943), showing the metaluminous character of lamprophyres and hybrid quartz diorite^granodiorite whereas the composite dykes are slightly peraluminous. (b) CIPW normative Q^Ab^Or
triangle. In both diagrams the hybrids define a trend between equigranular granite and lamprophyre. Low-SiO2 porphyritic granite samples
follow the same trend.
Fig. 15. Harker variation diagrams for the Karkonosze granite and its hybrid rocks.
379
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Fig. 16. Chondrite-normalized REE patterns for the hybrid quartz diorite^granodiorite (a) and lamprophyre dykes (b). Normalization values
are from Masuda et al. (1973) divided by 12.
Accepting that the hybrid quartz diorites^granodiorites
formed by mixing between lamprophyric and granitic
magmas, it would be interesting to know when this event
took place in the crystallization history of the granite. In
(Na2O þ K2O)/CaO vs Al2O3 and (MgO/Fe2O3) vs SiO2
plots (Fig. 21) and in all Harker diagrams, the hybrids plot
along straight lines linking equigranular granite and lamprophyre. These diagrams efficiently discriminate between
fractional crystallization (dotted line, Fig. 21) and mixing
(continuous line) trends. The mixing and crystallization
trends intersect at SiO2 contents and (Na2O þ K2O)/
CaO ratios characterizing the less differentiated equigranular granites. This indicates that mixing occurred early in
the magmatic history during the first stages of fractional
crystallization. This conclusion is reinforced by the fact
that, in the same diagrams, the less differentiated porphyritic granites are the more mixed (Fig. 21). Field relationships also favour early emplacement of the hybrid
quartz diorites^granodiorites (Z›ak & Klominsky, 2007).
Microgranular magmatic enclaves (MME)
and composite dykes
Fig. 17. Primitive mantle-normalized (Sun & McDonough, 1989)
multi-element diagrams for hybrid quartz diorite^granodiorite (a)
and lamprophyres (b).
an average lamprophyre and a slightly differentiated equigranular granite (sample EQU-5) define the grey-shaded
field in Fig. 20. That all the hybrid quartz diorites^granodiorites plot in this field is perfectly consistent with Fig. 18,
which shows the size of trace-element anomalies in hybrids
increasing from mafic to felsic compositions.
The MME and composite dykes were emplaced at a late
stage into the granite; indeed, some dykes cut the more differentiated facies of the equigranular granite. In the
MME, SiO2 contents range between 6824 and 6977%
except for one sample (MME-1, with 6433% SiO2). They
have Mg-number between 042 and 031 and are Na2Orich with Na2O/K2O typically 42 (in hybrid quartz diorites^granodiorites this ratio is 1); A/CNK is in the
range 1^11 (Table 13). The composite dykes form a rather
homogeneous group (6742%5SiO256946%, except for
COM-1 with 6233% SiO2; Table 13). Mg-number is low
(030^025) with Na2O/K2O typically 51 and A/CNK 1
380
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Fig. 18. Trace element abundances and ratios vs SiO2 (wt %); data are normalized (N) to primitive mantle values (Sun & McDonough, 1989).
Fig. 19. C(average HYB) C(parental magma) vs C(lamprophyre) C(parental magma) diagrams (Fourcade & Alle'gre, 1981) for the average hybrid quartz
diorite^granodiorite (a) and a porphyritic granite (POR-1) (b). In both cases, the major element compositions plot on a straight line that passes
through the origin, consistent with an origin of the hybrid and POR-1 by mixing between lamprophyric and equigranular granitic magmas.
as for enclaves (Fig. 14a, Table 13). The composite dyke
(Na2O þ K2O)/CaO (435^555) and MgO/Fe2O3
(014^022) values both differ from their equivalents in
the hybrid quartz diorites^granodiorites (17^38 and
030^046) and in MME (188^308 and 032^036)
(Fig. 21). Consequently, in most Harker diagrams (Fig. 15),
the composite dykes plot on different trends from the
mixing trend of the hybrid quartz diorites^granodiorites.
These trends point towards a more mafic, silica-poor endmember that is not lamprophyre in composition.
Consequently, if the dykes originated by the same process
as the hybrids, at least the mafic component was different.
A (CaO/Na2O) vs Al2O3 diagram (Fig. 22) clearly discriminates between the trends followed by the hybrid quartz
diorites^granodiorites, enclaves and dykes. Whereas all the
enclaves and dykes point towards a granite composition,
only the hybrid quartz diorites^granodiorites appear
directly related to lamprophyres.
The enclave REE patterns (Fig. 23a) differ from those of
the composite dykes (Fig. 23b). They show distinctly
381
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Fig. 20. Chondrite-normalized REE patterns (a) and primitive mantle-normalized trace element patterns (b) showing the result of mixing
modelling. The grey field corresponds to all possible mixing combinations between the average lamprophyre and an equigranular granite
(sample EQU-7).
Fig. 21. (a) (Na2O þ K2O)/CaO vs Al2O3 and (b) (MgO/Fe2O3) vs SiO2 (wt %) diagrams. Dashed line indicates fractional crystallization
trend; continuous line indicates mixing trend.
Fig. 22. (CaO/Na2O) vs Al2O3 (wt %) diagram, showing that
hybrids, mafic microgranular magmatic enclaves (MME) and composite dyke define different trends, indicating different evolutionary
histories.
different LREE contents; in the composite dykes, LaN is
4100 and typically less in the MME. In both, some samples (MME-4, COM-3, COM-4 and COM-6; black symbols in Fig. 23) have low HREE contents and small
negative Eu anomalies very similar to those of some lamprophyres (e.g. LAM-3). Others have high HREE contents
associated with pronounced negative Eu anomalies.
In primitive mantle-normalized multi-element diagrams
(Sun & McDonough, 1989; Fig. 24), negative anomalies are
generally more prominent in the composite dykes than in
the MME. Composite dykes show a slightly positive Zr
anomaly, which is more marked in the MME. However,
the main difference between these two rock types is a significant positive Yanomaly in the MME, which is not seen
in the granites, lamprophyres or hybrid quartz diorites and
granodiorites. Only two composite-dyke samples (COM-1
and COM-5) show a slight Y positive anomaly. The origin
of the Y anomaly and the contrasted geochemical behaviour of Yand HREE await explanation.
382
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Fig. 23. Chondrite-normalized REE patterns for microgranular magmatic enclaves (MME) (a) and composite dyke (b). Normalization values
are from Masuda et al. (1973) divided by 12.
Fig. 25. Log (Ni) vs SiO2 (wt %) diagram, showing that hybrid
quartz diorite^granodiorite, microgranular magmatic enclaves
(MME) and composite dykes define different trends, indicating that
they followed different evolutionary paths.
Fig. 24. Primitive mantle-normalized (Sun & McDonough, 1989)
multi-element diagrams for mafic microgranular magmatic enclaves
(a) and composite dyke (b).
Mixing in microgranular magmatic enclaves (MME)
and composite dykes
As with the hybrid quartz diorites^granodiorites, field and
petrographic evidence indicates that both the MME and
the composite dykes were hybridized. However, their
compositional range is narrower than in the hybrid
quartz diorites^granodiorites, which span the whole range
from equigranular granite to lamprophyre (Fig. 15). As
compositional trends defined by both MME and composite dykes converge on equigranular or silicic porphyritic
granite (Figs 15, 20 and 21), the latter can be considered
one end-member involved in the mixing. Unfortunately,
the other end-member has not yet been identified. The evolutionary trends defined for the composite dykes and
MME do not point towards lamprophyric compositions
(Figs 21 and 22); lamprophyre is unlikely to have been the
other end-member. However, some MME (MME-4) and
composite dykes (COM-3, COM-4 and COM-6) have
trace-element patterns similar to those of the
383
JOURNAL OF PETROLOGY
VOLUME 49
NUMBER 2
FEBRUARY 2008
Fig. 26. Log (Ni) vs SiO2 (wt %) (a) and (CaO/Na2O) vs Al2O3 (wt %) (b) diagrams synthesizing the temporal and chemical evolution of
Karkonosze granitic magma. Dashed lines indicate fractional crystallization trends (FC); continuous lines indicate mixing trend.
lamprophyres, thus a genetic link with lamprophyres is
considered possible.
For these rocks, the mafic, mixing end-member was lamprophyre and another mafic magma linked to lamprophyre. A genetic link may reflect partial melting of a
single source or fractional crystallization of a unique parental magma. As lamprophyres are generated by melting
of enriched mantle (Awdankiewicz et al., 2005a), the mafic
end-member for the MME and the composite dykes could
also have the same source. However, mantle melting would
produce magmas with relatively high Mg-number and
high Ni contents (Mg-number ¼ 047^059 and Ni
100 ppm in lamprophyres; Table 11), which is not the
case for the dykes (Mg-number ¼ 025^030 and Ni
4 ppm). The remelting of residual mantle would result in
even higher values.
Enclave and granite Ni contents (Fig. 25) may provide
some insight. Ni contents in the composite dykes are lower
than in all porphyritic and most equigranular granites;
this argues against their efficient contamination by granitic
material. Consequently, the basic end-member in mixing
was already strongly depleted in Ni. During mantle partial
melting or fractional crystallization of lamprophyric
1 and behave
magma, Ni will always have Kdsolid=melt
Ni
as a strongly compatible element. The contrasting behaviour of compatible elements during fractional crystallization and partial melting allows a distinction between
these two processes. Whereas partial melting cannot efficiently decrease the compatible element content in magmatic liquids, on the contrary fractional crystallization
strongly impoverishes magmas in these elements (i.e.
Hanson, 1980). Thus, it seems that the very low Ni contents
in the basic end-member involved in composite-dyke
mixing could have been achieved only by fractional crystallization. In addition, the pronounced negative Sr, Eu, P
and Ti anomalies (Fig. 24) characterizing both the composite dykes and the MME indicate fractionation of plagioclase-, apatite- and Ti-bearing phases. In contrast, the
positive Zr anomaly points to a lack of zircon
fractionation.
As noted above, the composite-dyke compositional
trends also point to an equigranular granite composition.
However, in contrast to the hybrid quartz diorite and
granodiorite trends, the dyke trend points towards the
most evolved and differentiated equigranular granite
(Figs 15, 20 and 24). This indicates that this mixing event
took place late in the differentiation history of the
Karkonosze granite, a conclusion supported by field and
petrographic observation.
Magmatic evolution
The above discussion shows that limited fractional crystallization (F520%) occurred in the Karkonosze granite.
Mixing also occurred between a felsic and a more mafic
lamprophyric magma. Hybrid quartz diorites^granodiorites reveal that lamprophyre interacted with granitic
magma at an early stage, before much of the crystallization took place. In contrast, the composite dykes were
emplaced into, and interacted with, an already differentiated granitic magma. MME compositions fall between
those of the hybrid quartz diorites^granodiorites and
those of the composite dykes (Figs 21 and 24), suggesting
that they could have interacted with granite after the
hybrid quartz diorites^granodiorites had formed but
before the dykes had done so. This relative chronology is
consistent with the experimental work of Hallot et al.
(1994, 1996), who showed that the shape of a mafic magma
injection into a felsic magma depends on the relative viscosity of both magmas. A small difference in viscosity
favours more complete mixing, a higher viscosity contrast
leads to spheroidal microgranular magmatic enclaves and,
where the contrast is very high, emplacement of the mafic
magma as dykes. As magma viscosity correlates with
degree of differentiation (increasing polymerization and
crystal load), continuous injection of mafic magma into a
crystallizing granitic pluton would result in mixed hybrid
granodiorites, MME and dykes in that order (see also
Barbarin, 2005). The sequence seen in the Karkonosze
pluton indicates that mafic (lamprophyric) magma was
384
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Table 16: Sm-Nd isotopic data of the Karkonosze pluton
Sample
Sm (ppm)
Nd (ppm)
143
Nd/144Nd
2s error ( 106)
147
Sm/144Nd
2s error ( 106)
e(0 Ga)
e(032 Ga)
Equigranular granite
EQU-11
16
63
0512179
33
015353
23
895
720
EQU-12
39
139
0512356
11
016963
25
550
440
EQU-13
23
97
0512307
14
014335
22
646
428
Porphyritic granite
POR-2
535
0512279
7
012430
19
700
405
POR-4
11
49
221
0512305
13
013413
20
650
394
POR-8
58
278
0512353
9
012613
19
556
268
POR-9
086
24
0512407
12
020975
31
451
504
POR-21
48
201
0512220
19
014437
22
815
602
LAM-3
71
383
0512410
5
011207
17
445
099
LAM-4
61
407
0512348
6
009070
14
566
133
Lamprophyre
Hybrid quartz diorite and granodiorite
HYB-2
617
2873
0512410
5
012983
19
445
172
HYB-5
83
51
0512312
12
009839
15
636
234
HYB-10
73
35
0512310
5
012618
19
640
352
HYB-11
74
377
0512317
5
011867
18
626
308
Microgranular magmatic enclave
MME-4
36
215
0512371
14
010126
15
521
131
MME-6
47
151
0512381
5
018817
28
501
467
Nd^Sr isotopic data
143
Fig. 27. eNd vs SiO2 (wt %) indicating mixing between mafic (lamprophyre) and felsic (equigranular granite) magmas. Symbols are as
in previous figures.
injected into the granite throughout the granite crystallization history of the granite.
The composition of the mafic end-member also became
increasingly more differentiated. Thus, the history of the
Karkonosze pluton involved the parallel evolution of two
reservoirs, one granitic, the other lamprophyric.
Interactions between these two reservoirs continued as the
differentiationof bothprogressedças summarized in Fig.26.
Nd/144Nd ratios were measured in 16 samples and eNd(T)
recalculated for an age of 320 Ma, the 40Ar^39Ar age determined for the Karkonosze granite (Marheine et al., 2002)
(Table 16). In a plot of eNd(T) vs SiO2 (Fig. 27), the negative
correlation of most of the data clearly corroborates the
magma mixing hypothesis indicated by the major- and
trace-element patterns. The higher eNd(T) of the lamprophyres could be consistent with a mantle origin. However, to
date, no positive eNd(T) values have been reported from this
massifçsuggesting that even the more primitive mafic
magmas had already reacted with crustal rocks. It is also possible that the lamprophyres originated by partial melting of
an enriched mantle with a relatively low eNd(T).
In contrast, the low eNd(T) (5 7) of the equigranular
granites is consistent with a crustal origin. Porphyritic-facies
rocks are characterizedby a slightly less negative eNd(T), indicating that they could have interacted with more primitive
magmas. Earlier studies (Mierzejewski et al.,1994) reported
eNd(T) ^35 for the porphyritic granite, which is in the same
range as those analysed in this work. Hybrid rocks have
eNd(T) intermediate between lamprophyres and granites.
385
JOURNAL OF PETROLOGY
VOLUME 49
Duthou et al. (1991) also proposed a crustal origin for the
granite, based on Sr isotope data, considering the protolith
to be mostly mafic. The conclusion that the Karkonosze
granite originated predominantly by melting of a crustal
source is supported by major element evidence for its
weakly peraluminous character (Fig. 4). It is also consistent
with the observation that the equigranular granites plot
close to the minima on the cotectics of the ‘hydrous granitic
system’ of pressures ranging between 1 and 2 kbar (Fig. 5b).
In conclusion, the Nd isotope data confirm that the
composition of the Karkonosze granite resulted from
long-term interactions between two evolving magmas, one
being of mantle (possibly enriched) origin, the other the
result of crustal melting. This also indicates that the granite
does not have a single global isotopic initial ratio, but
rather one varying from place to place that depends on
the degree of mixing between the mafic and felsic endmembers, thus making highly disputable the interpretation
of data alignment in isochron plots in terms of age.
D I S C U S S ION A N D C ONC LU S ION S
The Karkonosze pluton largely comprises equigranular
granite and porphyritic granite. The entire pluton, except
for the equigranular granite component, was affected by
mixing processes. The porphyritic granite, representing a
volume of4500 km3 (Cwojdzin‹ski et al., 1991), had its original magmatic composition totally modified by interaction
with contemporaneous mafic magmas. This implies that
huge volumes of mafic magma were available. Given a
degree of mixing of 15%, as calculated for the least silicic
porphyritic granite (Fig. 19b), the volume of mafic lamprophyric magma can be estimated at 75 km3. The role
played by mafic magma, therefore, was not negligible or
subordinate. Indeed, hot mafic magma might well have
supplied much of the heat necessary to start and maintain
crustal melting; part of this heat could have been released
by latent heat of crystallization.
Only a very small part of the Karkonosze granite
escaped mixing with mafic magmas. This includes the
equigranular granite and a subordinate part of the porphyritic granite, which represent relatively small volumes
of differentiated magmas (SiO2470 wt %). The equigranular granite does not contain enclaves or bodies of
hybrid quartz diorite or hybrid granodiorite; it is cut only
by lamprophyre dykes or some late composite dykes.
Feldspars from the equigranular granite are homogeneous
or, in some cases, show a faint continuous normal zoning.
They are devoid of mantled structures or resorption
features. The zoning, together with geochemical modelling, indicates that the evolution of this granite involved
small (520%) degrees of fractional crystallization.
The equigranular granite has a composition close to the
minima on cotectics in the Q^Ab^Or^H2O system at
water pressure of 1^2 kbar; protracted fractional
NUMBER 2
FEBRUARY 2008
crystallization was not possible. Accessory minerals, abundant in this granite type, played an important role during
magma differentiation. Small degrees of crystallization of
major minerals (biotite þ plagioclase þ magnetite) would
not have significantly modified the major-element composition of the magma. In contrast, the fractionation of small
amounts of accessory phases such as allanite, zircon and
apatite was able to significantly modify the budget of
some trace elements (Figs 11 and 12). Thus, the history of
fractional crystallization is more clearly recorded by trace
than by major elements.
Interaction between mafic and felsic magmas took different forms: (1) homogeneous hybrid quartz diorites and
granodiorites reflecting two magmas that have been
relatively intimately mixed; (2) rounded and lobate
MME^mafic magmas coexisting with large volumes of
granite melt; (3) composite ductile stretched dykes with
rare chilled margins; (4) late intrusive lamprophyre dykes
with chilled margins. As shown by several workers
(Furman & Spera, 1985; Sparks & Marshall, 1986; Frost &
Mahood, 1987; Hallot et al., 1994, 1996; Barbarin, 2005) all
of these features result from differing degrees of intermagma viscosity contrast; with increasing contrast, homogeneous hybridization gives way to rounded mafic
enclaves, composite dykes and, finally, late mafic dykes.
As a result of cooling and increasing crystal contents
during granitic magma crystallization, the felsic magma
viscosities increase strongly. Thus, it is possible to link
each type of magmatic interaction with a stage of granite
differentiation. Early injection of mafic magma into a
low-viscosity, melt-rich granitic mass allowed relatively
homogeneous mixing to produce hybrid quartz diorites^
granodiorites. Later injections into more fully crystallized
granite produced MME and, later, composite dykes.
Finally, injection into almost totally crystallized granite
resulted in dykes with sharp contacts and chilled margins.
The recognition of all of these interaction styles in
Karkonosze indicates that injections of mafic magma took
place throughout the granite crystallization history; the
mafic magma source was long-lived and the conditions for
mantle melting were realized during at least the period of
the granite crystallization. Alternatively, the mafic magma
could have been stored in a deeper magma chamber and
injected episodically into the granitic pluton.
The episodic emplacement of mafic magmas at different
stages of granite crystallization is fairly common. Very
often, two or more compositional types of magmatic
enclaves are reported; for example, in the Mont Blanc
granite, where Mg-rich and Fe-rich enclaves led Bussy
(1987, 1990) to conclude that two melts of mafic to intermediate composition had coexisted with the granite
magma. The parallel evolution of granite and mafic
magmas, and their recurring interaction throughout granite crystallization, has been described from the Bono
386
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
granodiorite in Sardinia (Zorpi et al., 1989, 1991; Bouchet,
1992). Bouchet (1992) demonstrated that these mafic and
felsic magmas interacted from the beginning until the end
of granite crystallization. In the course of time the mafic
magma also crystallized and differentiated; hence the composition of late mafic inputs is more evolved than that of
early injections. In Karkonosze, compatible elements such
as Ni reveal that the mafic magma interacting with the
granite became progressively impoverished in Ni with
time from hybrids to enclaves and finally to composite
dyke. Unlike partial melting, fractional crystallization is a
highly efficient process to impoverish the magma in compatible elements. Consequently, the Ni content decrease in
the mafic component can be logically interpreted in terms
of fractional crystallization. The data indicate that both
felsic and mafic magmas evolved independently by fractional crystallization, which, in the case of the
Karkonosze granite, argues for a deep-seated magma
chamber rather than for continuous mantle melting. In
summary, in Karkonosze, two magma sources (mantle
and crust) melted almost contemporaneously. Then the
two magma reservoirs evolved independently by fractional
crystallization. However, episodically the mafic magma
intruded into crystallizing granite, with attendant various
degrees of interaction.
In the Karkonosze granite, several lines of evidence indicate dynamic magma movement. Parallel alignments of
both megacrysts and enclaves point to magma flow. Zones
almost exclusively composed of feldspar megacrysts and
little matrix suggest, regardless of the exact process of feldspar accumulation (crystal settling, filter pressing, etc.),
relative movement of crystals and liquid. The rapakivi textures characterizing the alkali-feldspar megacrysts in the
hybrid rocks show that the feldspars were mechanically
introduced from the granite into the mafic magma (Saby
& Go«tze, 2004). Feldspar megacrysts astride contacts
between hybrid and porphyritic granite demonstrate the
capture of granite-derived feldspar by the mafic magma.
In addition, feldspar crystals show evidence of repeated
episodes of resorption and regrowth as a result of rapid
changes in magma composition (Saby & Go«tze, 2004;
Saby et al., 2007a, 2007b). This zoning is interpreted as a
result of mineral crystallization and transfer within a heterogeneous magmatic flow field caused by mafic^felsic
magma interaction. Similar feldspar migrations have
been reported in numerous magma-chamber systems
(Vernon, 1986; Cox et al., 1996; Tepley et al., 1999; Davidson
et al., 2001; Troll & Schmincke, 2002; Perini et al., 2003; Troll
et al., 2004). Obviously, a well-stirred magma would favour
more efficient mixing and mingling. Emplacement would
have been the most obvious cause of granite magma movement but convection induced by the introduction of hot
mafic magma batches may have contributed (Wiebe, 1996;
Janous› ek et al., 2004).
Since Archaean times, the association of lamprophyres
with crustal magmas has been fairly common; for example,
in the late Archaean Closepet granite (Jayananda et al.,
1995; Moyen et al., 2001, 2003a, 2003b). Most of the
Archaean sanukitoids are also spatially and genetically
associated with lamprophyre-like rocks (Shirey &
Hanson, 1984; Stern & Hanson, 1991; Halla, 2005; LobachZhuchenko et al., 2005; Samsonov et al., 2005). The association of lamprophyre with granite and/or monzodiorite is
common in Hercynian granites, e.g. in Spain (Bea et al.,
1999), Brittany (Barrie're, 1977; Albare'de et al., 1980), Mont
Blanc (Bussy, 1990), the French Central Massif (Lameyre
et al., 1980; Barbarin, 1983; Solgadi et al., 2007), Corsica
and Sardinia (Zorpi et al., 1989, 1991; Bouchet, 1992),
the Vosges (Pagel & Leterrier, 1980) and in Bohemia
(Fo«rster et al., 1999; Janous› ek et al., 2000). In all these cases
a mixed origin is invoked, implying both mantle and crust
magmatic inputs. The assumed mantle source is, in many
cases, a fertile peridotite possibly enriched by earlier subduction (Jayananda et al., 2000; Moyen et al., 2001). Most
of these granites correspond to the KCG (K-rich and
K-feldspar porphyritic calc-alkaline granitoids) as defined
by Barbarin (1999). The Karkonosze granite is not an
exception.
AC K N O W L E D G E M E N T S
We are deeply grateful to B. Bonin and V. Janous› ek for
their very constructive and thorough reviews, and to
Marjorie Wilson for efficient editorial oversight and very
helpful comments. We appreciate very much friendly assistance by R. Macdonald and P. Kennan, who substantially
improved the scientific content and who, in addition, corrected both English style and grammar. We are also
indebted to B. Bonin, B. Barbarin, M. S›temprok, J. Z›a¤k,
M. Mierzejewski and A. Wilamowski for stimulating and
fruitful discussions on the field in the Polish and Czech
part of the Karkonosze. We acknowledge R. Bachlin¤ski
for assistance in the isotope laboratory, as well as
P. Dzier_zanowski and L. Je_zak in the microprobe laboratory. The work has been funded by KBN grant 307/1766/B/
PO1/2007/33, BW 1642 and BW 1761/13.
R EF ER ENC ES
Albare'de, F., Dupuis, C. & Taylor, H. P. (1980). 18O/16O evidence for
non-cogenetic magmas associated in a 300 Ma old concentric
pluton at Ploumanac’h (Brittany, France). Journal of the Geological
Society, London 137, 641^647.
Aleksandrowski, P. & Mazur, S. (2002). Collage tectonics in the northeasternmost part of the Variscan Belt; the Sudetes, Bohemian
Massif. In: Winchester, J. A., Pharaoh, T. C. & Verniers, J. (eds)
Palaeozoic Amalgamation of Central Europe. Geological Society,
London, Special Publications 201, 237^277.
Anderson, J. L. & Smith, D. R. (1995). The effects of temperature and
fO2 on the Al-in-hornblende barometer. American Mineralogist 80,
549^559.
387
JOURNAL OF PETROLOGY
VOLUME 49
Annen, C., Scaillet, B. & Sparks, R. S. J. (2006). Thermal constraints
on the emplacement rate of a large intrusive complex: the Manaslu
leucogranite, Nepal Himalaya. Journal of Petrology 47, 71^95.
Awdankiewicz, M., Awdankiewicz, H. & Kryza, R. (2005a).
Petrology of mafic and felsic dykes from the eastern part of the
Karkonosze massif. Polish Mineralogical Society, Special Papers 26,
111^114.
Awdankiewicz, M., Awdankiewicz, H. & Kryza, R. (2005b). The richterite minette from Bukowiec (Karkonosze^Izera block):
Petrological characteristics. Polish Mineralogical Society, Special Papers
26, 115^118.
Bacon, C. R. & Druitt, T. H. (1988). Compositional evolution of
the zoned calcalkaline magma chamber of Mount Mazama,
Crater Lake, Oregon. Contributions to Mineralogy and Petrology 98,
224^256.
Barbarin, B. (1983). Les granites carbonife'res du Forez septentrional
(Massif Central franais). Typologie et relations entre diffe¤rents
massifs. Thesis, Univ. Clermont-Ferrand II, pp. 177.
Barbarin, B. (1999). A review of the relatioships between granitoid
types, their origins and their geodynamic environments. Lithos 46,
605^626.
Barbarin, B. (2005). Mafic magmatic enclaves and mafic rocks associated with some granitoids of the central Sierra Nevada batholith,
California: nature, origin, and relations with the hosts. Lithos 80,
155^177.
Barker, F. (1979). Trondhjemites: definition, environment and hypothesis of origin. In: Barker, F. (ed.) Trondhjemites, Dacites and Related
Rocks. Amsterdam: Elsevier, pp. 1^12.
Barnes, C. G., Burton, B. R., Burling, T. C., Wright, J. E. &
Karlsson, H. R. (2001). Petrology and geochemistry of the Late
Eocene Harrison Pass Pluton, Ruby Mountains Core Complex,
northeastern Nevada. Journal of Petrology 42, 901^929.
Barrie're, M. (1977). Le complexe de Ploumanac’h, massif armoricain,
Essai sur la mise en place et l’e¤volution pe¤trologique d’une association plutonique subalcaline tardi-oroge¤nique. Thesis, Univ. Brest,
pp. 290.
Barrie're, M. (1981). On curved laminae, graded layers, convection currents and dynamic crystal sorting in the Ploumanac’h (Brittany)
subalkaline granite. Contributions to Mineralogy and Petrology 77,
214^224.
Bateman, R. (1995). The interplay between crystallization, replenishment and hybridization in large felsic magma chambers. EarthScience Reviews 39, 91^106.
Bea, F., Pereira, M. D. & Stroh, A. (1994). Mineral/leucosome traceelement partitioning in a peraluminous migmatite (a laser ablation-ICP-MS study). Chemical Geology 117, 291^312.
Bea, F., Montero, P. & Molina, J. (1999). Mafic precursors, peraluminous granitoids, and late lamprophyres in the Avila batholith: a
model for the generation of Variscan batholiths in Iberia. Journal
of Geology 107, 399^419.
Berg, G. (1923). Der Granit des Riesengebirges und seine Ganggesteine (petrographische Studien). Abhandlungen der Preussischen Geologischen
Landesanstalt 94.
Blundy, J. & Cashman, K. (2001). Ascent-driven crystallisation of
dacite magmas at Mount St Helens, 1980^1986. Contributions to
Mineralogy and Petrology 140, 631^650.
Bonin, B. (2004). Do coeval mafic and felsic magmas in postcollisional to within-plate regimes necessarily imply two contrasting, mantle and crustal, sources? A review. Lithos 78, 1^24.
Bonin, B. (2007). A-type granites and related rocks: Evolution of a concept, problems and prospects. Lithos 97, 1^29.
Borkowska, M. (1966). Petrography of Karkonosze granite. Geologia
Sudetica 2, 7^119.
NUMBER 2
FEBRUARY 2008
Bouchet, G. (1992). Me¤langes magmatiques et gene'se des granito|« des
calco-alcalins: l’exemple du complexe tonalo-granodioritique de
Bono (Sardaigne septentrionale). Etude pe¤trologique et ge¤ochimique. Thesis, Univ. Saint-Etienne, pp. 310.
Brenan, J. M., Neroda, E., Lundstrom, C., Shaw, H. F., Ryerson, F. J.
& Phinney, D. L. (1998). Behaviour of boron, beryllium, and
lithium during melting and crystallization: Constraints from
mineral^melt partitioning experiments. Geochimica et Cosmochimica
Acta 62, 2129^2141.
Bussy, F. (1987). Interactions physico-chimiques entre le granite du
Mont-Blanc et ses enclaves. Schweizeriche Mineralogische und
Petrographische Mitteilungen 67, 380^384.
Bussy, F. (1990). Pe¤trogene'se des enclaves microgrenues associe¤es
aux granitoides calco-alcalins: exemple des massifs varisques
du Mont Blanc (Alpes occidentales) et mioce'ne du Monte
Capanne (Ile d’Elbe, Italie). Memoires de Geologie (Lausanne) 7, pp.
309.
Castro, A., Moreno-Ventas, I. & De la Rosa, J. D. (1990).
Microgranular enclaves as indicators of hybridisation processes
in granitoid rocks, Hercynian belt, Spain. Geological Journal 25,
391^404.
Cloos, H. (1925). Einfu«hrung in die tektonische Behandlung magmatischer
Erscheinungen (Granittektonik). I Spezial Teil. Das Riesengebirge in
Schlesien. Gebru«der Borntraeger, Berlin.
Cox, R. A., Dempster, T. J., Bell, B. R. & Rogers, G. (1996).
Crystallization of the Shap granite: evidence from zoned
K-feldspar megacrysts. Journal of the Geological Society, London 153,
625^635.
Cwojdzin‹ski, Z., Cymerman, Z., Jerzman‹ski, J., Kro¤likowski, L. &
Sawicki, L. (1991). Geologiczna interpretacja wynikow zastosowania
metody strippingu dla poznania budowy wglebnej obszaru dolnoslaskiego.
Wrocaw: Polish Geological Institute.
Dallmeyer, R. D., Franke, W. & Weber, K. E. B. (1995). Pre-Permian
Geology of Central and Eastern Europe. Springer: Berlin.
Davidson, J. P., Tepley, F. J., Palacz, Z. & Main, S. (2001). Magma
recharge, contamination and residence time revealed by in situ
laser ablation isotopic analysis of feldspar in volcanic rocks. Earth
and Planetary Science Letters 182, 427^442.
Didier, J. (1973). Granites and their Enclaves. The Bearing of Enclave on the
Origin of Granites. Amsterdam: Elsevier.
Didier, J. & Barbarin, B. (1991). Enclaves and Granite Petrology.
Amsterdam: Elsevier.
Diot, H., Masur, S. & Pin, C. (1995). Karkonosze batholith
(NE Bohemian Massif): The evidence for pluton emplacement
during transtensional^extensional collapse. Journal of the Czech
Geological Society 40, 62.
Droop, G. T. R. (1987). A general equation for estimating Fe3þ concentrations in ferromagnesian silicates and oxides using stoichiometric
criteria. Mineralogical Magazine 51, 431^435.
Duthou, J. L., Couturie¤, J. P., Mierzejewski, M. P. & Pin, C. (1991).
Rb/Sr age of the Karkonosze granite on the base of the whole
rock method. Przegla˜ d Geologiczny 2, 75^79.
Elburg, M. A. (1996). Evidence of isotopic equilibration
between microgranitoid enclaves and host granodiorite,
Warburton Granodiorite, Lachlan Fold Belt, Australia. Lithos 38,
1^22.
Ewart, A. & Griffin, W. L. (1994). Application of proton-microprobe
data to trace-element partitioning in volcanic rocks. Chemical
Geology 117, 251^284.
Finger, F. & Steyrer, H. P. (1990). I-type granitoids as indicators of a
late Paleozoic convergent ocean^continent margin along the southern flank of the central European Variscan Orogen. Geology 18,
1207^1210.
388
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Finger, F., Roberts, M. P., Haunschmid, B., Schermaier, A. &
Steyrer, H. P. (1997). Variscan granitoids of Central Europe; their
typology, potential sources and tectonothermal relations.
Mineralogy and Petrology 61, 67^96.
Fo«rster, H. J., Tischendorf, G., Trumbull, R. B. & Gottesmann, B.
(1999). Late collisional granites in the Variscan Erzgebirge,
Germany. Journal of Petrology 40, 1613^1645.
Fourcade, S. & Alle'gre, C. J. (1981). Trace element behavior in granite
genesis: a case study. The calc-alkaline plutonic association from
Querigut complex (Pyre¤ne¤es, France). Contributions to Mineralogy
and Petrology 76, 177^195.
Fourcade, S., Martin, H. & de Bremond d’Ars, J. (1992). Chemical
exchange in migmatites during cooling. Lithos 128, 43^53.
Franke, W. (2000). The mid-European segment of the Variscides:
tectonostratigraphic units, terrane boundaries and plate
tectonic evolution. In: Franke, W., Haak, V., Oncken, O. & Tanner,
D. (eds) Orogenic Processes: Quantification and Modelling in the
Variscan Belt. Geological Society, London, Special Publications 179, 35^61.
Franke, W., Matte, P. & Tait, J. (2005). Europe; Variscan Orogeny. In:
Encyclopedia of Geology;Volume 2. Elsevier: Oxford, pp. 75^86.
Frost, T. P. & Mahood, G. A. (1987). Field, chemical, and physical constraints on mafic^felsic magma interaction in the Lamarck
Granodiorite, Sierra Nevada, California. Geological Society of
America Bulletin 99, 272^291.
Furman, T. & Spera, T. (1985). Co-mingling of acid and basic magma
with implications for the origin of mafic I-type xenoliths, field and
petrochemical relations of an unusual dike complex at Eagle Peak
Lake, Sequoia National Park, California, U.S.A. Journal of
Volcanology and Geothermal Research 24, 151^178.
Halla, J. (2005). Late Archean high-Mg granitoids (sanukitoids) in the
southern Karelian domain, eastern Finland: Pb and Nd isotopic
constraints on crust^mantle interactions. Lithos 79, 161^178.
Hallot, E., Auvray, B., de Bremond d’Ars, J., Davy, P. & Martin, H.
(1994). New injection experiments in non-Newtonian fluids. Terra
Nova 6, 274^281.
Hallot, E., Davy, P., de Bremond d’Ars, J., Auvray, B., Martin, H. &
van Damme, H. (1996). Non-Newtonian effects during injection in
partially crystallised magmas. Journal of Volcanology and Geothermal
Research 71, 31^44.
Hammastrom, J. M. & Zen, E. (1986). Aluminium in hornblende: an
empirical igneous geobarometer. American Mineralogist 71,1297^1313.
Hanson, G. N. (1980). Rare earth elements in petrogenetic studies of
igneous systems. Annual Review of Earth and Planetary Sciences 8,
371^406.
Hollister, L. S., Grissom, G. C., Peters, E. K., Stowell, H. H. &
Sisson, V. B. (1987). Confirmation of the empirical correlation of
Al in hornblende with pressure of solidification of calc-alkaline
plutons. American Mineralogist 72, 231^239.
Hoskin, P., Kinny, P., Wyborn, D. & Chappell, B. (2000).
Identifying accessory mineral saturation during differentiation in
granitoid magmas: an integrated approach. Journal of Petrology 41,
1365^1396.
Icenhower, J. P. & London, D. (1996). Experimental partitioning of
Rb, Cs, Sr, and Ba between alkali feldspar and peraluminous
melt. American Mineralogist 81, 719^734.
Irvine, T. N. & Baragar, W. R. A. (1971). A guide to the chemical classification of the common volcanic rocks. Canadian Journal of Earth
Sciences 8, 523^548.
Janous› ek, V., Bowes, D. R., Braithwaite, C. J. R. & Rogers, G. (2000).
Microstructural and mineralogical evidence for limited involvement of magma mixing in the petrogenesis of Hercynian high-K
calc-alkaline intrusion; the Kozarovice Granodiorite, Central
Bohemian Pluton, Czech Republic. Transactions of the Royal Society of
Edinburgh, Earth Sciences 91, 15^26.
Janous› ek, V., Braithwaite, C. J. R., Bowes, D. R. & Gerdes, A. (2004).
Magma-mixing in the genesis of Hercynian calc-alkaline granitoids: an integrated petrographic and geochemical study of the
Sazava intrusion, Central Bohemian Pluton, Czech Republic.
Lithos 78, 67^99.
Jayananda, M., Martin, H., Peucat, J.-J. & Mahabaleswar, B. (1995).
Late Archaean crust^mantle interactions in the Closepet granite,
Southern India: evidence from Sr^Nd isotopes, major and trace
element geochemistry. Contributions to Mineralogy and Petrology 119,
314^329.
Jayananda, M., Moyen, J.-F., Martin, H., Peucat, J.-J., Auvray, B. &
Mahabaleswar, B. (2000). Late Archaean (2550^2520 Ma) juvenile
magmatism in the Eastern Dharwar craton, southern India: constraints from geochronology, Nd^Sr isotopes and whole rock geochemistry. Precambrian Research 99, 225^254.
Johnson, M. C. & Rutherford, M. (1989). Experimental calibration of
the aluminium-in-hornblende geobarometer with application to
Long Valley caldera (California) volcanic rocks. Geology 17, 837^841.
Kerim, K. (2006). Hybridization of mafic microgranular enclaves:
mineral and whole-rock chemistry evidence from the Karamadazi
Granitoid, Central Turkey. International Journal of Earth Sciences 95,
587^607.
Klominsky, J. (1969). Krkonossko-jizersky granitoid massif. Sbornik
Geologickich Ved, Geologie 15, 7^132.
Kro«ner, A., Hegner, E., Hammer, J., Haase, G., Bielicki, K. H.,
Krauss, M. & Eidam, J. (1994). Geochronology and Nd^Sr systematics of Lusatian granitoidsçsignificance for the evolution of
the Variscan orogen in East^Central Europe. Geologische Rundschau
83, 357^376.
Kryza, G., Kusnierz, A. & Majerowicz, A. (1979). Cyrkony z granitoidow Karkonoszy oraz wschodniej czesci krystaliniku izerskiego.
Acta Universitatis Wratislaviensis, Prace Geologiczno Mineralogiczn 7,
107^150.
Kuno, H. (1966). Lateral variation of basalt magma types across continental margins and island arcs. Bulletin of Volcanology 29, 195^222.
Lameyre, J., Autran, A., Barrie're, M., Bonin, B., Didier, J., Fluck, P.,
Fourcade, S., Giraud, P., Jonin, M., Orsini, J.-B. & Vivier, G.
(1980). Les granitoides de France. In: Autran, A. & Dercourt, J.
(eds) Evolutions ge¤ ologiques de la France. Me¤ moires du BRGM 107, 51^97.
Leake, B. E., Woolley, A. R., Arps, C. E. S. et al. (1997). Nomenclature
of amphiboles: report of the subcommittee on amphiboles of
the International Mineralogical Association Commission on New
Minerals and Mineral Names. Mineralogical Magazine 61, 295^321.
Lobach-Zhuchenko, S. B., Rollinson, H. R., Chekulaev, V. P.,
Arestova, N. A., Kovalenko, A. V., Ivanikov, V. V., Guseva, N. S.,
Sergeev, S. A., Matukov, D. I. & Jarvis, K. E. (2005). The
Archaean sanukitoid series of the Baltic Shield: geological setting,
geochemical characteristics and implications for their origin. Lithos
79, 107^128.
Mahood, G. A. & Hildreth, E. W. (1983). Large partition coefficients
for trace elements in high-silica rhyolites. Geochimica et Cosmochimica
Acta 47, 11^30.
Marheine, D., Kachlik, V., Maluski, H., Patocka, F. & Zelazniewicz,
A. (2002). The 40Ar/39Ar ages from the West Sudetes (NE Bohemian
Massif): constraints on the Variscan polyphase tectonothermal
development. In: Winchester, J. A., Pharaoh, T. & Verniers, J.
(eds) Palaezoic Amalgamation of Central Europe. Geological Society,
London, Special Publications 201, 133^155.
Masuda, A., Nakamura, N. & Tanaka, T. (1973). Fine structures of
mutually normalized rare-earth patterns of chondrites. Geochimica
et Cosmochimica Acta 37, 239^244.
389
JOURNAL OF PETROLOGY
VOLUME 49
Matte, P. (1986). Tectonics and plate tectonics model for the Variscan
Belt of Europe. Tectonophysics, 126, 329^374.
Matte, P. (1998). Continental subduction and exhumation of
HP rocks in Paleozoic belts; Uralides and Variscides In:
Linnemann, U., Heuse, T., Bankwitz, P. & Falka, O. (eds.) GFF,
120, 209^222.
Matte, P., Maluski, H., Rajlich, P. & Franke, W. (1990). Terrane boundaries in the Bohemian Massif; result of large-scale Variscan shearing. Tectonophysics, 177, 151^170.
Mazur, S. (1995). Structural and metamorphic evolution of the country rocks at the eastern contact of the Karkonosze granite in the
southern Rudawy Janowickie Mts and Lasocki Ridge. Geologia
Sudetica 29, 31^98.
Mazur, S. & Aleksandrowski, P. (2001). The Tepla(?)/Saxothuringian
suture in the Karkonosze^Izera Massif, western Sudetes, Central
European Variscides. International Journal of Earth Sciences 90,
341^360.
Mierzejewski, M. P. & Oberc, D. T. (1990). The
Izera^Karkonosze Block and its tectonic development (Sudetes,
Poland). Neues Jahrbuch fu«r Geologie und Pala«ontologie, Abhandlungen
179, 197^222.
Mierzejewski, M. P., Pin, C., Duthou, J. L. & Couturie¤, J. P. (1994).
Sr^Nd isotopic study of the Karkonosze granite (Western Sudetes).
In: Kryza, R. (ed.) Igneous Activity and Metamorphic Evolution of the
Sudetes Area. Wroclaw: Universytet Wroclawski, 82(1).
Moyen, J.-F., Martin, H. & Jayananda, M. (2001). Multi-element geochemical modelling of crust^mantle interactions during lateArchaean crustal growth: the Closepet granite (South India).
Precambrian Research 112, 87^105.
Moyen, J.-F., Jayananda, M., Ne¤delec, A., Martin, H.,
Mahabaleswar, B. & Auvray, B. (2003a). From the roots to the roof
of a granite: the Closepet granite of South India. Journal of the
Geological Society of India 62, 753^758.
Moyen, J.-F., Martin, H., Jayananda, M. & Auvray, B. (2003b). Late
Archaean granites: a typology based on the Dharwar Craton
(India). Precambrian Research 127, 103^123.
Nash, W. P. & Crecraft, H. R. (1985). Partition coefficients for trace
elements in silicic magmas. Geochimica et Cosmochimica Acta 49,
2309^2322.
O’Connor, J. T. (1965). A classification for quartz-rich igneous rocks
based on feldspar ratios. US Geological Survey, Professional Papers
525-B, 79^84.
Pagel, M. & Leterrier, J. (1980). The subalkaline potassic magmatism
ot the Ballons massif (Southern Vosges, France). Shoshonitic affinity. Lithos 13, 1^10.
Pearce, J. A. & Norry, M. J. (1979). Petrogenetic implications of Ti, Zr,
Yand Nb variations in the volcanic rocks. Contributions to Mineralogy
and Petrology 69, 33^47.
Perini, G., Tepley, F. J., III, Davidson, J. P. & Conticelli, S. (2003). The
origin of K-feldspar megacrysts hosted in alkaline potassic rocks
from central Italy: a track for low-pressure processes in mafic
magmas. Lithos 66, 223^240.
Perugini, D., Poli, G. & Mazzuoli, R. (2003). Chaotic advection, fractals and diffusion during mixing of magmas: evidence from lava
flows. Volcanology and Geothermal Research 124, 255^279.
Pin, C., Mierzejewski, P. M. & Duthou, J. L. (1987). Isochronous age
Rb/Sr of Karkonosze granite from the quarry Szklarska Pore“ba
Huta and significance of initial ratio 87Sr/86Sr in this granite.
Przegla˜ d Geologiczny 35, 512^516.
Przywo¤ski, L. (2006). Chemical and CL study on apatite as an indicator of Karkonosze granite petrogenesis. MSc thesis, University of
Warsaw.
NUMBER 2
FEBRUARY 2008
Rayleigh, J. (1896). Theoretical considerations respecting the separation of gases by diffusion and similar processes. Philosophical
Magazine 42, 77^107.
Rickwood, P. C. (1989). Boundary lines within petrologic diagrams
which use oxides of major and minor elements. Lithos 22, 247^263.
Robert, C. P. & Casella, G. (2004). Monte Carlo Statistical Methods.
Springer: New York.
Samsonov, A. V., Bogina, M. M., Bibikova, E. V., Petrova, A. Y. &
Shchipansky, A. A. (2005). The relationship between adakitic,
calc-alkaline volcanic rocks and TTGs: implications for the tectonic setting of the Karelian greenstone belts, Baltic Shield. Lithos
79, 83^106.
Schmidt, M. W. (1992). Amphibole composition in tonalite as a
function of pressure: an experimental calibration of the Al in hornblende barometer. Contributions to Mineralogy and Petrology 110,
304^310.
Shabani, A. A. T., Lalonde, A. E. & Whalen, J. B. (2003).
Composition of biotite from granitic rocks of the Canadian
Appalachian orogen: a potential tectonomagmatic indicator?
Canadian Mineralogist 41, 1381^1396.
Shand, S. J. (1943). Eruptive Rocks. Their Genesis, Composition,
Classification and their Relations to Ore-deposits. Hafner Publishing
Co.: New York.
Shirey, S. B. & Hanson, G. N. (1984). Mantle derived Archaean monzodiorites and trachyandesites. Nature 310, 222^224.
Saby, E. & Galbarczyk-Ga˜ siorowska, L. (2002). Barium in alkali feldspar megacrysts from Szklarska Poreba Huta porphyritic granite:
possibly indicator of magma mixing. Mineralogical Society of Poland,
Special Papers 20, 198^200.
Saby, E. & Go«tze, J. (2004). Feldspar crystallization under magmamixing conditions shown by cathodoluminescence and geochemical modellingça case study from the Karkonosze pluton
(SW Poland). Mineralogical Magazine 68, 541^557.
Saby, E. & Martin, H. (2005). Mechanisms of differentiation of the
Karkonosze granite. Polish Mineralogical Society, Special Papers 26,
264^267.
Saby, E., Galbarczyk-Gasiorowska, L., Seltmann, R. & Mu«ller, A.
(2007a). Alkali feldspar megacryst growth: geochemical modelling.
Mineralogy and Petrology 89, 1^29.
Saby, E., Seltmann, R., Kober, B., Mu«ller, A., GalbarczykGa˜ siorowska, L. & Jeffries, T. (2007b). LREE distribution patterns
in zoned alkali feldspar megacrystsçimplication for parental melt
composition. Mineralogical Magazine 71, 193^217.
Solgadi, F., Vanderhaeghe, O., Moyen, J.-F., Sawyer, E. & Reisberg, L.
(2007). Generation of synorogenic Hercynian granites in the
Livradois area, French Massif Central: The relative roles of crustal
anatexis and mantle derived magmas. Canadian Mineralogist 45,
581^606.
Sparks, R. S. J. & Marshall, L. A. (1986). Thermal and mechanical
constraints on mixing between mafic and silicic magmas. Journal
of Volcanology and Geothermal Research 29, 99^124.
Stern, R. A. & Hanson, G. N. (1991). Archaean high-Mg granodiorite:
a derivative of light rare earth enriched monzodiorite of mantle
origin. Journal of Petrology 32, 201^238.
Sto«rmer, J. C. & Nicholls, J. (1978). XLFRAC: a program for interactive testing of magmatic differentiation models. Computers and
Geosciences 87, 51^64.
Streck, M. J. & Grunder, A. L. (1997). Compositional gradients and
gaps in high-silica rhyolites of the Rattlesnake Tuff, Oregon.
Journal of Petrology 38, 133^163.
Sun, S. S. & McDonough, W. F. (1989). Chemical and isotopic systematics of oceanic basalts: implications for mantle composition
and processes. In: Saunders, A. D. & Norry, M. J. (eds)
390
SLABY AND MARTIN
MAGMA INTERACTION, KARKONOSZE PLUTON
Magmatism in the Ocean Basins. Geological Society, London, Special
Publications 42, 313^345.
Tepley, F. J., Davidson, J. P. & Clynne, M. A. (1999). Magmatic interactions as recorded in plagioclase phenocrysts of Chaos Crags,
Lassen volcanic center, California. Journal of Petrology 40, 787^806.
Troll, V. R. & Schmincke, H. U. (2002). Magma mixing and crustal
recycling recorded in Tertiary feldspar from compositionally
zoned peralkaline ignimbrite ‘A’, Gran Canaria, Canary Islands.
Journal of Petrology 43, 243^270.
Troll, V. R., Donalson, C. H. & Emeleus, H. (2004). Pre-eruptive
magma mixing in ash-flow deposits of the Tertiary Rum
igneous centre, Scotland. Contributions to Mineralogy and Petrology
147, 722^739.
Vernon, R. H. (1986). K-feldspar megacrysts in granitesçphenocrysts,
not porphyroblasts. Earth-Science Reviews 23, 1^63.
Waight, T. E., Dean, A. A., Maas, R. & Nicholls, I. A. (2000). Sr and
Nd isotopic investigations towards the origin of feldspar megacrysts
in microgranular enclaves in two I-type plutons of the Lachlan
Fold Belt, southeast Australia.. Australian Journal of Earth Science 47,
1105^1112.
Wall, V. J., Clemens, J. D. & Clarke, B. (1987). Models for granitoid
evolution and source compositions. Journal of Geology 95, 731^749.
Watson, E. B. (1982). Basalt contamination by continental crust: some
experiments and models. Contributions to Mineralogy and Petrology 80,
73^87.
Wiebe, R. A. (1996). Mafic^silicic layered intrusions: the role of basaltic injections on magmatic processes and the evolution of silicic
magma chambers. Transactions of the Royal Society of Edinburgh, Earth
Sciences 87, 233^242.
Wiebe, R. A., Blair, K. D., Hawkins, D. P. & Sabine, C. P. (2002).
Mafic injections, in situ hybridization, and crystal accumulation in
the Pyramid Peak granite, California. Geological Society of America
Bulletin 114, 909^920.
Wilamowski, A. (1998). Srodowisko geotektoniczne intruzji granitowych Tatr i Karkonoszy w swietle danych geochemicznych.
Archiwum Mineralogiczne 52, 261^271.
Wnorowska, U. (2006). Enclaves from Karkonosze granite as an
example of magma mixing processesçevidence from CL,
Nomarski DIC microscopy, combined with local chemical analyses
of feldspars. MSc thesis, TU Bergakademie, Freiberg.
Z›ak, J. & Klominsky, J. (2007). Magmatic structures in the Krkonos› e^
Jizera Plutonic Complex, Bohemian Massif: evidence for localized
multiphase flow and small-scale thermal^mechanical instabilities
in a granitic magma chamber. Journal of Volcanology and Geothermal
Research 164, 254^267.
Z›ak, J.,Vyhnalek, B. & Kabele, P. (2006). Is there a relationship between
magmatic fabrics and brittle fractures in plutons? A view based on
structural analysis, anisotropy of magnetic susceptibility and
thermo-mechanical modelling of the Tanvald pluton (Bohemian
Massif). Physics of the Earth and Planetary Interiors 157, 286^310.
Ziegler, P. (1986). Geodynamic model for the Paleozoic crustal consolidation of western and central Europe. Tectonophysics 126, 303^328.
Zorpi, M. J., Coulon, C., Orsini, J.-B. & Corcita, C. (1989). Magma
mingling, zoning and emplacement in calc-alkaline granitoid plutons. Tectonophysics 157, 315^329.
Zorpi, M. J., Coulon, C. & Orsini, J.-B. (1991). Hybridization between
felsic and mafic magmas in calc-alkaline granitoidsça case study
in Northern Sardinia, Italy. Chemical Geology 92, 45^86.
391