JOURNAL OF PETROLOGY
VOLUME 44
NUMBER 4
PAGES 603±627
2003
Constraints on the Source Components of
Lavas Forming the Hawaiian North Arch and
Honolulu Volcanics
H.-J. YANG1 *, F. A. FREY2 AND D. A. CLAGUE3
1
DEPARTMENT OF EARTH SCIENCES, NATIONAL CHENG-KUNG UNIVERSITY, TAINAN, TAIWAN 701
2
DEPARTMENT OF EARTH, ATMOSPHERIC AND PLANETARY SCIENCES, MASSACHUSETTS INSTITUTE OF
TECHNOLOGY, CAMBRIDGE, MA 02139, USA
3
MONTEREY BAY AQUARIUM, RESEARCH INSTITUTE, MOSS LANDING, CA 95039-0628, USA
RECEIVED NOVEMBER 2, 2001; ACCEPTED SEPTEMBER 30, 2002
Hawaiian volcanoes, dominantly shields of tholeiitic basalt,
form as the Pacific Plate migrates over a hotspot in the mantle.
As these shields migrate away from the hotspot, highly alkalic
lavas, forming the rejuvenated stage of volcanism, may erupt
after an interval of erosion lasting for 025±25 Myr. Alkalic
lavas with geochemical characteristics similar to rejuvenatedstage lavas erupted on the sea floor north of Oahu along the
Hawaiian Arch. The variable Tb/Yb, Sr/Ce, K/Ce, Rb/La,
Ba/La, Ti/Eu and Zr/Sm ratios in lavas forming the North
Arch and the rejuvenated-stage Honolulu Volcanics were controlled during partial melting by residual garnet, clinopyroxene,
Fe±Ti oxides and phlogopite. However, the distinctively high
Ba/Th and Sr/Nd ratios of lava forming the North Arch and
Honolulu Volcanics reflect source characteristics. These characteristics are also associated with shield tholeiitic basalt; hence
they arise from the Hawaiian hotspot, which is interpreted to be
a mantle plume. Inversion of the batch melting equation using
abundances of highly incompatible elements, such as Th and La,
requires enriched sources with 10±55% clinopyroxene and
5±25% garnet for North Arch lavas. The 87Sr/86Sr
and 143Nd/144Nd ratios in lavas forming the North Arch and
Honolulu Volcanics are consistent with mixing between the
Hawaiian plume and a depleted component related to midocean ridge basalts. Specifically, the enrichment of incompatible
elements coupled with low 87Sr/86Sr and high 143Nd/144Nd
relative to bulk Earth ratios is best explained by derivation
from depleted lithosphere recently metasomatized by incipient
melt (52% melting) from the Hawaiian plume. In this
metasomatized source, the incompatible element abundances,
as well as Sr and Nd isotopic ratios, are controlled by incipient
melts. In contrast, the large range of published 187 Os/188 Os
data (0134±0176) reflects heterogeneity caused by various
proportions of pyroxenite veins residing in a depleted peridotite
matrix.
*Corresponding author. Telephone: 011-886-6-2757575, ext. 65429.
Fax: 011-886-6-2740285. E-mail: [email protected]
Journal of Petrology 44(4) # Oxford University Press 2003; all rights
reserved.
Hawaiian plume; Honolulu Volcanics; North Arch;
plume±lithosphere interaction; rejuvenated stage; trace element
geochemistry; alkalic lavas
KEY WORDS:
INTRODUCTION
After a period of quiescence and erosion, ranging from
025 to 25 Myr, volcanism at many Hawaiian volcanoes terminates with eruption of rejuvenated-stage
lavas consisting of alkalic basalts, nephelinites and
melilitites. Rejuvenated-stage or `post-erosional' lavas
occur on the shields of Haleakala (Hana Volcanics),
Koolau (Honolulu Volcanics), Kauai (Koloa Volcanics)
and Niihau (Kiekei Basalt). The lavas erupt from vents
scattered on the tholeiitic shields.
Submarine lavas compositionally and isotopically
similar to rejuvenated-stage lavas have erupted on
the sea floor north of Oahu along the Hawaiian Arch
(Fig. 1), which is a flexural arch that resulted from the
loading of the Hawaiian Islands. This volcanic field
covers an area of 25 000 km2 at water depths of 3900±
4380 m and is referred to as the North Arch Volcanic
Field (Clague et al., 1990). The age of North Arch flows
JOURNAL OF PETROLOGY
VOLUME 44
NUMBER 4
APRIL 2003
Fig. 1. (a) Dredge locations (, with lava flow numbers labelled) on the North Arch Volcanic Field, north of Oahu. Map modified from
Clague et al. (1990). (b) Location map for samples from the Honolulu Volcanics located on eastern Oahu. Modified from Clague &
Frey (1982).
ranges from 505 to 15 Ma (Clague et al., 1990; Dixon
et al., 1997; Clague & Dixon, 2000). This age range
overlaps with the estimated age of the rejuvenatedstage Honolulu Volcanics on Koolau Volcano
(Lanphere & Dalrymple, 1980; Clague & Frey,
1982). Although rejuvenated-stage lavas account
for 51% of the mass of each volcano, alkalic lava
apparently covers large areas of the Hawaiian Ridge.
The voluminous Hawaiian shields are generally
interpreted as surface manifestations of the Hawaiian
plume. However, the origin of the alkalic rejuvenatedstage and North Arch lavas is debated (Chen & Frey,
1983, 1985; Feigenson, 1984; Clague & Dalrymple,
1988). Compared with the dominantly tholeiitic
Hawaiian shields, the rejuvenated-stage and North
Arch lavas have higher 143 Nd/144 Nd and lower 87 Sr/
86
Sr. This result is surprising in that, despite their
relatively low Sm/Nd and high Rb/Sr, these alkalic
lavas were derived from sources with higher timeaveraged Sm/Nd and lower time-averaged Rb/Sr
than the sources of the shield lavas. Two types of
mixing mechanisms have been proposed to explain
the paradox between Nd and Sr isotopic ratios and
their corresponding parent/daughter (Sm/Nd and
Rb/Sr) ratios. Chen & Frey (1983, 1985) showed that
the inverse correlations between Rb/Sr and 87 Sr/86 Sr
and Sm/Nd vs 143 Nd/144 Nd defined by the shield to
rejuvenated-stage lavas of Haleakala volcano could be
explained by mixing between incipient melts (52%)
from a depleted source related to mid-ocean ridge
basalt (MORB) and melts from the mantle plume.
The essential part of this model is that incipient melts
of the depleted source inherit the isotopic ratios of the
source, but they will have much higher Rb/Sr and
lower Sm/Nd owing to low extents of melting. A similar
mixing model was proposed for the generation of
rejuvenated-stage lavas (Koloa Volcanics) on Kauai
(Feigenson, 1984; Clague & Dalrymple, 1988).
An alternative mixing model was used to explain the
compositional range and limited isotopic variations of
the Honolulu Volcanics. Roden et al. (1984) proposed
that the source of the Honolulu Volcanics formed by
adding small amounts (25%) of melt derived from a
MORB source by 03% melting to the plume source.
Melting of this mixed source to varying extents then
generated the Honolulu Volcanics. A similar model
was proposed by Reiners & Nelson (1998) for the
Koloa Volcanics on Kauai. In both types of mixing
models garnet lherzolite is the major source for the
magmas. Based on major and trace element compositions, volatile contents and limited isotopic data, a
similar model has been proposed for the source of the
North Arch lavas (Clague et al., 1990; Dixon et al.,
1997; Frey et al., 2000). Specifically, the North Arch
lavas were generated by variable but low extents of
melting of a homogeneous garnet lherzolite.
In contrast, Lassiter et al. (2000) argued that Os
isotopic ratios in rejuvenated-stage lavas of the Koloa
604
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
and Honolulu Volcanics cannot be explained by
plume±MORB source interaction, but that they are
consistent with mixing between melts derived from
lherzolite and pyroxenite forming the oceanic lithospheric mantle. This model differs significantly from
previous models in two aspects: (1) the Hawaiian
plume makes no contribution to the generation of rejuvenated-stage lavas; (2) an important role for pyroxenite is emphasized.
Discussions of the petrogenesis of Hawaiian
rejuvenated-stage lavas, especially inversion approaches
using trace element abundance data and melting
models (i.e. Watson, 1993; Zou & Zindler, 1996; Sims
& DePaolo, 1997), have relied heavily on the trace
element compositions of the Honolulu Volcanics
(Clague & Frey, 1982). However, data for some
elements reported by Clague & Frey (1982) are not
as precise and accurate as data obtained by current
analytical techniques, and data for some elements,
such as Nb, Y, Rb, Pb and U, are unavailable for
most samples. In this paper, we present trace element
data measured by inductively coupled mass spectrometry (ICP-MS) for 14 Honolulu Volcanics lavas and
21 North Arch samples, which were previously studied
(Clague & Frey, 1982; Frey et al., 2000). Our goal is to
compare the petrogenesis of lavas forming the North
Arch and Honolulu Volcanics. In particular, we:
(1) use variations in abundance of incompatible elements to constrain mineral proportions in the source;
(2) use abundance ratios of incompatible elements with
Sr and Os isotopic data to investigate the role of a
plume component in the North Arch and rejuvenatedstage lavas; (3) evaluate the evidence for a pyroxenite
source component.
SAMPLING
A subset of previously analyzed lavas from the North
Arch [Fig. 1a; 21 of 23 samples studied by Frey et al.
(2000)] and Honolulu Volcanics [Fig. 1b; 14 of 32
samples studied by Clague & Frey (1982)] were
selected for trace element analyses. The 14 samples
from the Honolulu Volcanics comprise two alkali
basalts, three basanites, five nephelinites and four
nepheline melilitites. North Arch lavas are glassy or
fine grained. Based on SiO2 content, we classify all of
the analyzed North Arch samples as alkali basalt and
basanite.
ANALYTICAL METHODS
The sample solutions were analyzed for Rb, Ba, Sr, Y,
Nb, Ta, Zr, Hf, Pb, Th, U and 14 rare earth elements
(REE) by ICP-MS at the Massachusetts Institute of
Technology. For each sample, 100 mg of powder was
digested using 35 ml HF (24N) and 05 ml HNO3 (7N)
at 250 F in a Teflon Savillex beaker for 48 h. The
sample was then heated to dryness and fluxed with
6N HCl for 24 h. The HCl solution was then taken to
dryness and converted to nitrate form using 3 ml of 7N
HNO3 and heated to dryness. The dried sample cake
was then dissolved in 5 ml of 7N HNO3, which was
subsequently diluted to 250 ml in 2N HNO3. US
Geological Survey (USGS) standard samples BHVO-1,
BCR-1, and AGV-1 were used to establish calibration
curves. Additional details have been given by Huang
& Frey (2003). The precision and accuracy of our
analysis are addressed in the following section.
RESULTS
Abundances of 25 trace elements are listed in Tables 1
and 2 together with the mean of 11 BHVO-2 (a USGS
standard) replicates, which were analyzed during the
course of this study (Huang & Frey, 2003). The complete major and trace element dataset may be downloaded from the Journal of Petrology website at http://
www.petrology.oupjournal.org. Based on these replicates, the analytical precisions are 2% (1 SD) for
most elements (Table 1). Duplicate analyses of eight
North Arch samples agree within 3% for most elements. Relative to the previous instrumental neutron
activation (INAA) data (Frey et al., 2000), the most
significant improvement is in precision of the Th data;
2±3% for ICP-MS (Table 1) compared with 10±12%
for INAA (Frey et al., 1990; Yang et al., 1996). Except
for Th, the relative agreement of data obtained by
INAA and ICP-MS is generally good (Appendix A).
As expected, there are more significant discrepancies
between the ICP-MS data and the older data for the
Honolulu Volcanics reported by Clague & Frey (1982)
(see Appendix A). To avoid systematic differences
between data obtained by different analytical techniques, we use the new ICP-MS data to evaluate previous interpretations and to provide new constraints on
the petrogenesis of the North Arch and Honolulu
Volcanics lavas.
Incompatible element abundances in
North Arch lavas
The data show that the abundances of highly and
moderately incompatible elements, such as Th, U,
light and middle rare earth elements (LREE and
MREE), high field strength elements (HFSE), K,
Rb, Ba and Sr, are positively correlated (Fig. 2a).
Two samples from dredge 24 (24-3 and 24-6) have
relatively lower TiO2, Zr, Hf, K2O and Rb concentrations compared with other samples with similar Th
contents (Fig. 2a). The abundance of the highly
605
Table 1: Abundances of trace elements (ppm) analyzed with ICP-MS for lavas from the Hawaiian North Arch
9-1
13
15-1
16-13
17-12
17-13
18-8
21-1
21-14
35-2
36
23-2
Group:
A
A
A
A
A
A
A
A
A
A
A
B
Rb
15.2
23.2
25.9
17.6
14.7
14.8
21.4
17.3
17.2
14.7
15.4
25.1
Ba
302
399
465
342
280
286
377
324
322
265
298
505
Sr
485
519
654
547
429
442
588
494
476
460
453
769
Y
Nb
Ta
Zr
Hf
La
Ce
Nd
Sm
Eu
Gd
Dy
Ho
Er
Tm
Lu
Pb
Th
U
132
2.51
162
23.3
33.3
1.89
147
19.6
29.3
1.67
113
20.1
28.9
1.66
111
25.0
40.2
2.28
155
21.0
32.0
1.81
118
19.0
31.9
1.75
107
21.3
26.7
1.50
122
21.8
28.0
1.50
112
22.9
53.6
3.01
189
4.39
2.81
22.5
3.25
24.9
3.91
31.5
3.48
24.6
2.69
20.3
2.75
20.5
3.68
27.6
2.80
22.8
2.64
22.2
2.95
19.7
2.68
20.3
45.8
5.96
50.3
6.41
62.5
51.4
6.72
41.1
41.4
5.27
55.2
7.16
45.2
44.0
5.49
41.3
40.2
38.1
74.4
24.0
5.25
26.0
5.80
21.3
4.71
28.9
6.45
5.48
22.9
5.27
21.9
9.92
39.3
1.73
5.18
1.88
5.84
1.59
4.70
2.10
6.37
5.15
1.73
4.90
1.64
8.13
2.54
0.738
4.01
0.806
4.24
0.724
3.78
0.922
4.79
5.04
0.764
5.03
0.740
7.15
0.987
0.724
1.79
0.766
1.83
0.720
1.70
0.892
2.15
4.10
0.753
4.12
0.783
4.84
0.833
0.230
1.38
0.241
1.43
0.244
1.43
0.281
1.68
1.83
0.245
1.87
0.259
1.84
0.230
0.195
1.80
0.193
2.31
0.192
2.21
0.225
2.19
1.46
0.201
1.56
0.222
1.36
0.176
2.61
0.721
3.03
0.799
2.38
0.646
3.18
0.877
1.65
2.17
1.88
2.41
2.87
4.44
0.608
0.629
1.25
8.10
32.9
7.23
2.32
6.74
0.994
5.07
0.919
2.13
0.284
1.67
0.222
3.62
3.67
0.964
27.7
6.35
2.01
6.05
0.870
4.54
0.827
1.97
0.266
1.54
0.210
1.92
2.70
0.747
5.28
21.5
4.67
1.57
4.60
0.691
3.73
0.693
1.68
0.232
1.36
0.190
1.66
2.35
0.634
5.89
23.8
5.13
1.73
5.35
0.754
3.97
0.772
1.85
0.244
1.43
0.200
1.70
2.75
0.745
22.1
4.82
1.61
4.78
0.693
3.64
0.677
1.64
0.224
1.33
0.179
1.63
2.70
0.721
APRIL 2003
Yb
119
2.20
26.1
45.3
NUMBER 4
Tb
1.67
21.2
38.0
VOLUME 44
606
Pr
20.1
30.6
JOURNAL OF PETROLOGY
Sample:
Sample:
23-6
26-9
27-1
27-2
27-4
22-2
24-3
24-6
34-2
BHVO-2
BHVO-2
Group:
B
B
B
B
B
C
C
C
C
11 replicates
1s %
29.2
24.9
25.9
25.0
25.9
7.50
17.5
19.1
14.6
9.48
1
564
466
470
462
483
191
432
479
268
135
2
Sr
840
650
655
633
658
306
630
712
532
399
2
25
2
19.0
1.22
1
Y
Nb
Ta
Zr
Hf
La
Ce
607
Pr
Nd
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
Pb
Th
U
24.6
62.1
3.47
215
25.1
48.0
2.61
164
4.85
45.3
3.90
31.7
92.2
11.36
66.7
8.31
44.7
9.03
33.4
7.11
2.90
8.72
2.22
6.29
1.087
5.33
0.939
4.82
0.889
1.90
0.883
2.10
0.237
1.42
0.279
1.65
0.181
3.47
0.224
2.42
5.13
1.39
3.96
1.07
22.5
48.1
2.70
164
3.80
33.0
66.1
8.25
33.1
6.86
2.20
6.77
0.904
4.47
0.794
1.86
0.233
1.37
0.181
2.36
3.85
1.01
22.3
48.6
2.71
164
22.5
48.3
2.74
163
19.3
16.7
0.817
67.3
22.0
44.4
2.36
141
24.5
50.2
2.59
156
23.8
30.0
1.68
141
178
2
1
3.82
32.8
3.87
32.8
1.73
14.1
3.09
33.4
3.49
37.7
3.24
23.6
4.42
15.2
2
65.9
8.19
66.7
8.36
27.5
3.54
66.8
8.24
70.1
9.19
51.9
6.59
38.4
5.57
1
32.9
7.01
33.3
6.77
14.7
3.45
32.6
6.85
36.9
7.57
27.0
6.07
24.9
6.16
1
2.20
6.61
2.24
6.80
1.19
3.65
2.17
6.47
2.42
6.96
1.97
5.57
2.03
6.13
1
0.889
4.56
0.923
4.60
0.599
3.51
0.874
4.47
0.980
4.95
0.851
4.56
0.963
5.30
2
0.790
1.79
0.803
1.85
0.678
1.73
0.800
1.82
0.878
2.04
0.860
2.11
1.01
2.50
2
0.236
1.37
0.229
1.40
0.238
1.46
0.244
1.46
0.274
1.59
0.298
1.78
0.350
2.05
3
0.182
2.44
0.183
2.36
0.206
1.26
0.204
2.43
0.215
2.84
0.248
6.69
0.286
1.53
3
3.91
1.05
4.00
1.09
1.81
0.471
4.04
1.07
4.47
1.19
2.63
0.703
1.30
0.446
3
See text for sample groups. Major element data are given in the Electronic Appendix.
2
1
1
2
2
1
1
2
2
SOURCE COMPONENTS OF HAWAIIAN LAVAS
Ba
YANG et al.
Rb
Table 2: Abundances of trace elements (ppm) analyzed with ICP-MS for lavas from the Honolulu Volcanics, Hawaii
Sample:
66PY-1
69KAL-2
65KAL-1
68BP2
GMQ-9
FS-2
68KAV-2
68KEE-1
69WIL-1
68TSV-1
65PAL-2
68SAL-23
65KPO-1
65KAPAA-11
Rock type:
N
NM
AB
N
NM
B
NM
N
N
NM
B
B
AB
N
20.5
26.3
15.9
27.6
46.9
17.9
35.6
25.1
25.2
33.3
19.6
27.1
8.10
26.0
Ba
686
964
352
716
925
351
1084
1388
782
1291
478
925
423
811
Sr
1046
1626
577
995
1762
508
1477
689
1301
1609
717
1105
587
941
Y
Nb
Ta
Zr
Hf
La
Ce
Pr
Sm
Eu
Gd
Tb
Er
Tm
Yb
Pb
Th
U
130
3.47
97.1
186
1.59
96.8
2.50
18.6
39.9
29.1
48.8
2.86
128
2.85
62.8
126
25.8
85.9
4.38
243
5.17
71.1
144
21.0
32.5
1.87
118
2.97
20.3
42.1
37.3
67.0
3.03
182
3.89
87.1
163
26.8
63.0
3.34
190
4.29
55.5
108
32.6
46.9
2.44
121
2.67
67.1
129
36.7
66.8
2.94
177
3.86
87.2
169
26.0
45.7
2.81
155
3.63
38.7
76.0
32.1
52.9
2.36
152
3.64
68.9
127
15.9
64.9
21.4
85.9
5.18
22.4
14.6
58.7
18.0
73.8
5.39
22.9
19.1
74.5
13.1
52.0
15.4
59.7
19.7
78.0
9.13
36.5
16.3
65.2
13.1
3.79
16.4
5.00
11.6
3.59
14.9
4.61
10.8
3.37
11.6
3.66
15.2
4.74
11.8
1.49
8.82
8.29
1.36
3.01
7.51
9.59
1.31
6.52
7.87
0.986
5.15
0.753
1.83
1.05
2.40
6.37
0.939
1.79
1.20
5.88
12.4
1.64
7.34
1.24
3.04
0.773
4.15
9.36
1.27
6.31
7.75
2.48
6.89
13.1
4.14
13.4
1.74
5.33
1.82
5.27
14.2
4.44
10.9
1.51
5.37
1.82
5.05
0.756
1.85
1.28
2.93
0.954
2.13
1.16
2.71
1.31
2.87
0.928
2.21
6.96
1.15
2.57
0.454
2.70
0.395
0.396
2.15
0.290
0.257
1.49
0.203
0.325
1.84
0.245
0.212
1.08
0.141
0.256
1.45
0.198
0.389
0.283
1.56
0.213
0.375
2.11
0.306
0.380
2.15
0.294
2.07
0.277
0.302
1.67
0.226
0.340
1.89
0.263
6.94
1.41
1.94
0.43
2.86
7.50
1.92
4.14
7.80
2.10
2.53
2.24
0.68
2.61
4.42
1.13
5.36
8.56
1.94
2.49
7.44
2.03
12.0
3.05
0.794
4.20
11.8
1.56
5.09
3.30
10.49
2.60
6.63
1.79
4.69
8.20
2.07
5.08
10.8
2.81
10.7
1.46
23.0
26.8
1.50
110
2.85
20.3
43.2
27.5
54.3
3.03
155
3.61
57.7
113
5.79
24.8
13.3
52.1
5.97
10.6
3.33
2.02
5.64
0.856
4.49
0.847
2.03
0.288
1.59
0.233
1.44
2.10
0.56
8.66
1.18
5.77
0.987
2.24
0.290
1.60
0.213
3.55
6.86
1.70
For rock type, AB, B, N and NM are abbreviations for 'alkali basalt', 'basanite', 'nephelinite', and 'nepheline melilitite', respectively. Major element data are included in the
Electronic Appendix.
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Lu
2.82
64.3
2.89
159
21.2
24.2
NUMBER 4
Dy
Ho
1.97
121
38.5
61.0
VOLUME 44
608
Nd
37.5
42.2
JOURNAL OF PETROLOGY
Rb
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
Fig. 2. (a) Abundances of La, Sm, Yb, TiO2, Nb, Zr, K2O, Rb, Ba and Sr vs Th content for samples from the Hawaiian North Arch Volcanic
Field (all in ppm, except for TiO2 and K2O, which are in wt %). Two labelled samples are relatively depleted in TiO2, Zr, K2O and Rb.
(b) Abundances of La, Sm, Yb, TiO2, Nb, Zr, K2O, Rb, Ba and Sr vs Th content for samples from the Honolulu Volcanics (all in ppm, except
for TiO2 and K2O, which are in wt %). The labelled samples in the Th vs TiO2 and Nb and Zr plots are the `low-TiO2 group' identified by
Clague & Frey (1982), except for sample GMQ-9.
incompatible element Th varies by almost a factor of
three, whereas that of heavy rare earth elements
(HREE) varies over a small range (e.g. a factor of
134 for Yb in Fig. 2a). Therefore, HREE were not
highly incompatible during the petrogenesis of North
Arch lavas, if these samples were derived from a common source as indicated by the similarities in their Sr,
Nd and Pb isotopic ratios (Frey et al., 2000). On a
primitive mantle normalized diagram, all the analyzed
North Arch samples are depleted in Zr, Hf and K and
enriched in Sr and Ba relative to their neighboring
elements (Fig. 3a). Some samples also have small
negative Ti anomalies and sample 34-2 shows a large
positive Pb anomaly that is confirmed by duplicate
analyses.
Incompatible element abundances in
Honolulu Volcanics lavas
The abundance of highly incompatible elements, such
as Th, increases from alkali basalt to basanite to nephelinite to nepheline melilitite. For simplicity in the
following discussion, alkali basalt and basanite refer
to the four samples with lowest abundance of incompatible elements (55 ppm Th in Fig. 2b). As in North
Arch lavas, the abundance of Th is positively correlated with that of LREE, MREE, Ba and Sr. However,
the Honolulu Volcanics extend to higher concentrations of incompatible elements (Fig. 2a and b).
Although somewhat scattered, the abundance of Yb
also increases with increasing Th content (Fig. 2b); this
trend contrasts with the absence of a Yb±Th correlation in the North Arch lavas (Fig. 2a). Relative to
trends for the North Arch lavas, plots of Th vs HFSE
for the Honolulu Volcanics are more scattered with
poorly defined positive trends. Four of our 14 analyzed
samples have relatively lower TiO2 contents at a given
Th content. They belong to the `low-TiO2 group'
identified by Clague & Frey (1982) (Fig. 2b). The
`low-TiO2 group' samples also have relatively low
abundances of Zr and Nb at a given Th content,
although the separations are not as obvious as in the
TiO2±Th plot (Fig. 2b). Sample GMQ-9 from vent
37 is distinct from other samples in its relatively high
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Fig. 3. Incompatible element abundances normalized to primitive mantle values (Sun & McDonough, 1989) for samples from the Hawaiian
North Arch (a) and Honolulu Volcanics (b). In (a), representative samples are shown to cover the ranges for each of the three groups. In (b),
all ICP-MS data are plotted.
abundance of Sm, HFSE, Rb, K and Sr and low
abundance of HREE (Fig. 2b), confirming the conclusion of Clague & Frey (1982, p. 486) that lava erupted
from this vent has distinctive geochemical characteristics. Sample 66PY-1 is characterized by high HREE
contents and sample 68KEE-1 has high Ba and low Sr
relative to the general trends (Fig. 2b). When normalized to primitive mantle values, four samples of alkali
basalt and basanite have relative depletions in Zr and
Hf and enrichments in Ba and Sr, similar to the patterns of North Arch lavas (Fig. 3a). In addition to Zr
and Hf depletions, nine nephelinites and nepheline
melilitites also have negative Ti anomalies but their
relative Sr abundances are variable (Fig. 3b).
DISCUSSION
Compositional variations in lavas:
source or process control
In a suite of primary lavas with limited variability in
isotopic ratios and significant compositional variation,
such as North Arch (Frey et al., 2000; Kani et al., 2000)
and Honolulu Volcanics (Lassiter et al., 2000), the
effects of variable extents of melting can be inferred
by plotting abundance ratios involving incompatible
elements against the concentration of a highly incompatible element. A constant abundance ratio over a
wide range of incompatible element concentration
indicates the source ratio (Hofmann et al., 1984),
whereas a systematic increase or decrease in abundance ratio reflects the effect of the melting process,
specifically the residual minerals that control the bulksolid/melt partition coefficients (D). For the North
Arch lavas, olivine is the only phenocryst, except for
three samples, 15-1, 18-8 and 36, which also contain
augite phenocrysts (Clague et al., 1990; Clague &
Dixon, 2000). However, these three samples have
CaO/Al2O3 ratios within the range of other North
Arch lavas, indicating that their compositions were
not affected by crystallization of augite; therefore, olivine was the only significantly fractionated silicate
phase. Dixon et al. (1997) and Frey et al. (2000)
inferred the compositions of primary melts for North
610
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
Arch lavas by incrementally adding calculated equilibrium olivine [KD ˆ (Fe/Mg)ol/(Fe/Mg)melt ˆ 03,
using measured Fe2O3/FeO ratios] to the glass and
whole-rock composition, respectively, until the lava
composition is in equilibrium with Fo91. Because the
Honolulu Volcanics are also inferred to be nearprimary magmas (Clague & Frey, 1982), we used the
same approach for these lavas.
North Arch lavas
Based on the variations in abundances of major and
trace elements and near isotopic homogeneity over the
compositional range, Frey et al. (2000) proposed that
North Arch lavas were derived from garnet lherzolite;
phlogopite and amphibole were not residual minerals
except for four samples with distinctively lower K/Ce
ratios. We evaluate these inferences using the new
ICP-MS data.
Garnet control on compositional variations. North Arch
lavas, as a whole, define trends in Th vs Tb/Yb, Sr/
Ce and Sr/Nd plots (Fig. 4). The positive Tb/Yb±Th
correlation (Fig. 4a) requires that bulk solid/melt
DTb 5 DYb. Because the experimentally determined
DTb/DYb ratios for clinopyroxene/melt, amphibole/melt
and phlogopite/melt partitioning are near unity (e.g.
Hart & Dunn, 1993; Hauri et al., 1994; LaTourrette
et al., 1995; Blundy et al., 1998; Lundstrom et al., 1998;
Dalpe & Baker, 2000), these phases cannot effectively
fractionate Tb from Yb. In contrast, it is well established the DTb/DYb ratios for garnet/melt partitioning
are 51 (Philpotts et al., 1972; Shimizu & Kushiro,
1975; Johnson, 1998; van Westrenen et al., 2000). For
example, the recent garnet/melt partitioning experiments of van Westrenen et al. (2000) show DTb/DYb
gt=melt
ratios as low as 02. Although DTb
was not measured in the experiments of Johnson (1998), it is
gt=melt
gt=melt
inferred to be 18 based on their DDy
and DEu
gt=melt
gt=melt
values, resulting in a DTb /DYb
of 024,
consistent with the results of van Westrenen et al.
(2000). Therefore, Tb is more incompatible than Yb
in garnet and the positive Tb/Yb±Th correlation
reflects the control of residual garnet.
In contrast to the positive Tb/Yb±Th correlation,
Sr/Ce and Sr/Nd ratios are inversely correlated with
Th contents (Fig. 4a) indicating that DSr 4 DCe and
DNd. These trends do not reflect the effects of residual
garnet which has DSr 5 DCe and DNd (e.g. Hauri et al.,
1994; Johnson, 1998; van Westrenen et al., 2000) or
residual clinopyroxene which has DSr DCe 5 DNd
(e.g. Blundy et al., 1998, fig. 3). The inverse Sr/Ce and
Sr/Nd vs Th trends are primarily defined by the
relatively low Sr/Ce and Sr/Nd ratios of samples with
Fig. 4. (a) Abundance ratios of incompatible elements vs the concentrations of Th and Ce adjusted to be in equilibrium with Fo91 for
North Arch lavas. North Arch samples are classified into three groups
(see discussion in text). The continuous lines indicate mixing between
most enriched Group B and least enriched Group A samples. Each
tick on the mixing lines indicates a 20% interval. PM indicates
primitive mantle value. The error bars indicate 1s uncertainty. For
panels with no error bars, the uncertainty is smaller than symbol size.
(b) Abundance ratios of Ti/Eu, Zr/Sm, Zr/Hf and Zr/Tb vs the Th
content adjusted to be in equilibrium with Fo91 for North Arch lavas.
The symbols are as in (a).
Th contents >3 ppm (Fig. 4a). The high compatibility
of Sr relative to Ce and Nd is a characteristic of
phlogopite and amphibole (LaTourrette et al., 1995;
Dalpe & Baker, 2000). The role of phlogopite and
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amphibole is evaluated in the next section using abundance ratios involving K, Rb and Ba.
The effects of residual K-bearing minerals on K, Rb and Ba.
Residual amphibole and phlogopite are major hosts for
K, Rb and Ba, which can result in low K/Ce, Rb/La
and Ba/La ratios in equilibrium melts (e.g. Class &
Goldstein, 1997). In contrast to the trends in the Th±
Tb/Yb and Th±Sr/Ce plots (Fig. 4), Frey et al. (2000)
noted the absence of a systematic variation in K/Ce vs
Ce plot for the North Arch lavas and suggested that a
K-bearing phase is not a residual phase, except for four
samples with distinctively lower K/Ce ratios. After the
effect of olivine fractionation is removed, 11 low-Ce
samples (referred to as Group A) range to lower K/
Ce than the six high-Ce samples (referred to as
Group B) (Fig. 4a). Moreover, Group A and B lavas
define positive and negative slopes, respectively, in Th
vs Rb/La, Nb/La and Ba/La plots (Fig. 4a). The other
four samples, 22-2, 24-3, 24-6 and 34-2 (referred to as
Group C), have distinctively lower K/Ce, Rb/La and
Nb/La ratios at a given Ce or Th content (Fig. 4a).
In Group B lavas, the increases in K/Ce, Rb/La and
Ba/La ratios with increasing extent of melting, as indicated by decreasing Th content (Fig. 4a), are consistent with control by residual K-bearing minerals such
as phlogopite or amphibole (Francis & Ludden, 1995;
Class & Goldstein, 1997). This inference is consistent
with their relatively lower Sr/Nd and Sr/Ce ratios
(Fig. 4a). In contrast, these ratios decrease in Group
A lavas with increasing extent of melting (Fig. 4a),
thereby indicating that K, Rb and Ba were more
incompatible than LREE during partial melting.
Therefore, K-bearing minerals were not residual
phases during generation of these lavas and the relative
K depletion and high Ba/Th ratios (>110) of Group A
lavas are source characteristics (Fig. 3a). The opposite
slopes defined by Group A and B lavas in Th vs Rb/La,
Ba/La and Nb/La plots suggest that these two groups
are not related by magma mixing (Fig. 4a). However,
the two groups could be explained by variable extents
of partial melting of a common source with K-bearing
residual minerals. That is, Group B lavas were derived
from relatively low extents of melting with residual
K-bearing minerals and Group A lavas were generated
by relatively higher extents of melting that exhausted
K-bearing minerals. This inference is consistent with
the limited Sr, Nd, and Pb isotopic variations in these
lavas (Fig. 5 and Frey et al., 2000; Kani et al. 2000).
Compared with Group A and B samples, the four
Group C samples have lower abundances of alkali
metals relative to LREE and Th (Fig. 4a). Three of
the four have relatively lower Ti/Eu, Zr/Sm and Zr/Tb
ratios at a given Th content (Fig. 4b). Moreover, two
Group C samples, 24-3 and 24-6, deviate from the
Fig. 5. 206 Pb/204 Pb vs 87 Sr/86 Sr plot for North Arch lavas. *, * and
circle with a cross are dredged samples analyzed by Frey et al. (2000),
which are classified into Group A, B and C, respectively, in this
study. ~ and & are samples collected by Dive 6K502 and 6K503
of Shinkai 6500 submersible in 1999 (Kani et al., 2000). The error
bars are indicated as 2s (Frey et al., 2000; Kani et al., 2000). Dive
6K502 samples overlap with Group A, B and C samples within
uncertainties. However, Dive 6K503 samples extend to lower 87 Sr/
86
Sr and 206 Pb/204 Pb values.
general Th±X correlations (Fig. 2a). Consequently,
Group C samples are distinct from other samples in
their relative depletions of alkali metals, Ti, Zr and Hf.
These complexities are likely to reflect source characteristics, although the only Group C sample analyzed
for isotopes has 87 Sr/86 Sr, 143 Nd/144 Nd and 206 Pb/204 Pb
ratios that overlap with those of Group A samples
(Fig. 5).
Source mineralogy constrained by the compatibility of Zr.
Group A and B lavas also differ in the compatibility
of Zr. Specifically, Group A lavas define a negative
Zr/Sm±Th trend (Fig. 4b) and have relatively constant
Zr/Tb ratios, implying DSm 5 DZr DTb. In contrast,
Group B lavas define a positive Zr/Tb±Th correlation
and have rather uniform Zr/Sm ratios, suggesting
DSm DZr 5 DTb (Fig. 4b). Therefore, the relative
compatibility of Zr and Sm is very different in Group A
and Group B lavas; hence the Zr depletion in the
primitive mantle normalized plot is probably caused
by the melting process (Fig. 3a). However, DSm 5 DZr
is not a characteristic of either residual clinopyroxene
(e.g. Hart & Dunn, 1993; Hauri et al., 1994; Blundy
et al., 1998; Lundstorm et al., 1998) or amphibole
(LaTourrette et al., 1995; Dalpe & Baker, 2000).
Fe±Ti oxides, such as ilmenite and rutile, have high
ilmenite=melt
DZr/DSm; i.e. DZr
is 03 (McCallum &
Charette, 1978; Pearce & Norry, 1979; McKay et al.,
ilmenite=melt
1986), significantly higher than DSm
(5001
based on McKay et al., 1986; Nielsen et al., 1992) and
612
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
Fig. 6. (a) Abundance ratios of incompatible elements vs the concentration of Th adjusted to be in equilibrium with Fo91 for samples from the
Honolulu Volcanics. Alkalic basalt and basanite have adjusted Th contents 55 ppm, whereas nephelinite and nepheline melilitite have
adjusted Th contents 45 ppm. The shaded fields indicate Group A and B North Arch lavas. The circle with a cross indicates North Arch
Group C lavas. The error bars indicate 1s uncertainty. For panels with no error bars, the uncertainty is smaller than symbol size. (b) Ti/Eu,
Zr/Sm, Nb/La, Nb/U and Zr/Hf ratios vs Th content adjusted to be in equilibrium with Fo91 for samples from the Honolulu Volcanics.
Symbols are as in (a). The labelled samples, except for GMQ-9, are the low-Ti samples identified by Clague & Frey (1982). The curve
represents mixing between samples with highest and lowest Th contents. The ticks on the mixing line indicate 20% interval.
rutile=melt
rutile=melt
DZr
/DSm
is 300 (Foley et al., 2000, fig. 1).
Also, in contrast to the typically chondritic Ti/Eu in
MORB and ocean island basalt (OIB) (e.g. Garcia
et al., 1996; Rhodes & Hart, 1996; Yang et al., 1996;
Niu et al., 1999), North Arch lavas have Ti/Eu ratios
slightly lower than the primitive mantle ratio of 7738
(Fig. 4b). In addition to Fe±Ti oxides, experimentally
produced garnet with grossularite content >20% have
DSm 5 DZr (Hauri et al., 1994; van Westrenen et al.,
1999). Compared with Group B lavas, Group A lava
could be explained by derivation from a source with
more Fe±Ti oxides or Ca-rich garnet. If Group A and B
lavas were derived from a common source, this inference requires that the amounts of residual garnet or
Fe±Ti oxides increase as extent of melting increases.
This is inconsistent with the experimentally determined melting stoichiometry showing that garnet
preferentially enters melts (Walter et al., 1995; Walter,
1998). The behavior of Fe±Ti oxides during partial
melting is not well constrained; however, spinel, a
ubiquitous oxide phase in the shallow mantle,
decreases in abundance as melting extent increases
(Kinzler, 1997). If both garnet and Fe±Ti oxides preferentially enter the melt, the greater compatibility of
Zr in Group A lavas which were derived by larger
extents of melting than Group B lavas is inconsistent
with derivation of Group A and B lavas from a common source. Despite the isotopic similarity of these
groups, we infer that the sources for these lavas differed
in their mineral proportions.
Honolulu Volcanics
Clague & Frey (1982) concluded that lavas forming
the Honolulu Volcanics were derived from a garnet
lherzolite mantle source. They also inferred that
K-bearing minerals and Ti oxides were important
residual minerals whose proportions varied in the
source. Here we use our new trace element abundance
data to evaluate and augment these conclusions.
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JOURNAL OF PETROLOGY
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Evidence for residual garnet. We find a positive correlation
between the abundance of Th and Tb/Yb ratio
(Fig. 6a) confirming the control of residual garnet,
consistent with the conclusion of Clague & Frey
(1982). Compared with North Arch lavas the
Honolulu Volcanics define a lower slope in Tb/Yb vs
Th plot (Fig. 6a), thereby reflecting a smaller proportion of garnet in the source of the Honolulu
Volcanics. This inference can also be readily derived
from the Th±Yb variation; the concentration of Yb
in the Honolulu Volcanics is positively correlated
with Th content (Fig. 2b), whereas Yb abundance
in North Arch lavas is buffered to within 30%
(Fig. 2a).
Evaluating the role of phlogopite. Both K and Rb are
mobile during subaerial alteration of Hawaiian lavas,
with Rb being more mobile than K, thereby leading to
unusually high K/Rb (e.g. Feigenson et al., 1984).
However, among the Honolulu Volcanics the strong
correlation between K and Rb, with a nearly constant
ratio of 317 26 for 12 of 14 analyzed samples, suggests
that K and Rb contents in these lavas were not
significantly affected by alteration. Alkali basalt
65KPO-1 has an unusually high K/Rb ratio of 543
and a relatively low Rb/La and K/Ce ratio compared
with samples with similar Th contents (Fig. 6a),
possibly reflecting Rb and K loss during alteration.
Basanite 65PAL-2 has a low K/Rb ratio of 229,
which might also reflect alkali mobility.
The broad negative correlations in plots of Th vs Sr/
Ce, Sr/Nd, K/Ce, Rb/La, Ba/La and Ba/Th ratios
(Fig. 6a) are consistent with control by residual phlogopite and/or amphibole (LaTourrette et al., 1995;
Dalpe & Baker, 2000). If the Honolulu Volcanics
were derived from a common source as indicated by
their homogeneous Sr and Nd isotopic ratios (Roden
et al., 1984; Lassiter et al., 2000), the large variation in
K/Ce, Rb/La and Ba/La ratios, by factors of 2±3, can
be explained by residual phlogopite which has
DK,Rb,Ba/DLREE,Th ratios 485 (LaTourrette et al.,
1995). Although amphibole also has DK,Rb,Ba >
DLREE,Th, its DK,Rb,Ba/DLREE,Th ratios (510) are not
large enough to compensate the effect of clinopyroxene
which has DK,Rb,Ba/DLREE,Th 501 (e.g. Hart &
Dunn, 1993; Lundstrom et al., 1998) and is more abundant than K-bearing minerals. The low abundances of
incompatible elements and high K/Ce, Rb/La, Ba/La
and Ba/Th ratios in alkali basalt and basanite (Th 5
4 ppm) indicate that these lavas were derived from
relatively larger extents of melting with no residual
phlogopite. Therefore, like Group A North Arch
lavas, the relative depletion in K and enrichment in
Ba of these lavas (Fig. 3b) reflect source characteristics.
Although some alkali basalts and basanites of
NUMBER 4
APRIL 2003
the Honolulu Volcanics overlap with North Arch
lavas in Th vs K/Ce, Rb/La and Rb/Ce plots, they
are distinct from North Arch lavas in their higher
Ba/La, Ba/Th and Sr/Th ratios at a given [Th]Fo91
(Fig. 6a).
Variations of HFSE: implications on source characteristics.
The Ti/Eu, Zr/Sm, Nb/La and Nb/U ratios in the
Honolulu Volcanics are inversely correlated with
Th content and vary much more than in the North
Arch lavas; e.g. Zr/Sm, which is similar to the
primitive mantle ratio in most oceanic basalts (Sun &
McDonough, 1989), varies by a factor of 23 in the
Honolulu Volcanics (Fig. 6b). At a given Th content
the low-TiO2 group has particularly low ratios of
Ti/Eu, Zr/Sm and Nb/U (Fig. 6b). The high-Th
melts, inferred to have formed by the lowest extents of
melting, also have prominent negative Ti anomalies
in a primitive mantle normalized diagram (Fig. 3b)
consistent with control by residual Fe±Ti oxides. With
high DTi/DEu, DZr/DSm, DNb/DU and DNb/DLa
(McCallum & Charette, 1978; Pearce & Norry, 1979;
McKay et al., 1986; Nielsen et al., 1992), residual Fe±Ti
oxides also result in decreasing Ti/Eu, Zr/Sm, Nb/La
and Nb/U ratios with decreasing melting extent
(Fig. 6b) and relative depletion in Zr and Hf (Fig. 3b).
The Zr/Hf ratio and Th content are positively correlated. The samples derived from largest extent of melting have Zr/Hf ratios approaching the chondritic value
(Fig. 6b), supporting the interpretation that high
Zr/Hf ratios in OIB reflect the melting process
(David et al., 2000). The high Zr/Hf ratio at low
extents of melting may be a consequence of equilibrating with Fe±Ti oxides. Clinopyroxene, however, has
DZr 5 DHf (e.g. Hart & Dunn, 1993; Hauri et al., 1994;
Blundy et al., 1998; Lundstrom et al., 1998; Salters &
Longhi, 1999); therefore at low extents of melting
magmas in equilibrium with clinopyroxene will have
relatively high Zr/Hf.
Alkali basalt and basanite, however, also show prominent Zr and Hf depletions in a primitive mantle
normalized diagram (Fig. 3b). Although they do not
have negative Ti anomalies, three of the four have
Ti/Eu 56500, lower than the primitive mantle value
(7738). These lavas, like North Arch Group A lavas,
may be derived from a source containing small
amounts of Ti oxides or Ca-rich garnet. However, the
alkali basalt and basanites of the Honolulu Volcanics
have Nb/U ratio 50, overlapping with the field for
North Arch lavas (Fig. 6b). Such values are typical for
OIB and MORB (Hofmann et al., 1986). Hence both
Nb/U and Zr/Hf in the source of the North Arch and
Honolulu Volcanics are similar to the sources of other
OIB, and the variable ratios in the lavas were caused
by the melting process.
614
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
The unusual composition of sample GMQ-9. Sample GMQ-9
collected from vent 37 is compositionally similar to
another sample from vent 37, 65MOIL-2, studied by
Clague & Frey (1982). Compared with other Honolulu
Volcanics lavas, these two samples have lower HREE
and Sc contents and higher HFSE, Sr and Rb contents
(Table 2, Fig. 4; Clague & Frey, 1982). Given the similarity in Sr and Nd isotopic ratios between samples
from vent 37 and from other vents of Honolulu Volcanics
(Roden et al., 1984), a different residual mineralogy is
required for vent 37 lavas (Clague & Frey, 1982).
Summary
Variations in abundance ratios of incompatible elements in lavas forming the North Arch and Honolulu
Volcanics (Figs 4 and 5) were primarily controlled
by residual phases such as garnet (causing variable
Tb/Yb), clinopyroxene (causing variable Zr/Hf ), Ti
oxides (causing variable Zr/Sm, Nb/La, Ti/Eu and
Nb/U) and phlogopite (causing variable K/Ce,
Rb/La, Sr/Ce, Sr/Nd and Ba/La). In contrast, some
distinctive features of these lavas, such as very high
Ba/Th (Figs 3 and 6a), the small positive Sr anomalies
in primitive mantle normalized diagrams (Fig. 3)
and the negative K anomalies in North Arch Group A
(Fig. 3a) reflect source characteristics.
Source characteristics inferred from
batch melting inversion
Assessment of inversions of batch melting equation
Batch melting is an end-member model that may be
appropriate for alkalic lavas formed by relatively small
extents of melting. Clague & Frey (1982) used the
inversion of the batch melting equation to constrain
bulk-solid/melt partition coefficients of element i (D0i )
by plotting the concentration of an incompatible element (i.e. Th) vs ratios of element abundances (i.e.
Th/La) (see Appendix B for the derivation of equations).
Based on the calculated D0i , they further inferred that
the source of Honolulu Volcanics is garnet peridotite.
However, Sims & DePaolo (1997) pointed out that this
approach has statistical limitations as a result of (1) the
small variation in the abundance ratio x/y relative to
the large range of concentration x and (2) both axes
depending upon x. To overcome these limitations,
Sims & DePaolo (1997) proposed to constrain D0i by
performing linear regression using two statistically
independent variables; 1/x vs 1/y (Appendix B).
Another model for partial melting is fractional melting. When fractional melts are pooled to form an accumulated fractional melt, the resulting melt composition
is similar to a batch melt (e.g. Langmuir et al., 1992).
Figure 7 shows model 1/Th vs 1/La and 1/Sm trends
Fig. 7. (a) Modelled 1/Th vs 1/Sm, and (b) modelled 1/Th vs 1/La
plots. The abundances of Th, La and Sm in melts are calculated from
non-modal batch melting (*) and non-modal fractional melting
(&; accumulated melts) with melting extents varying from 2 to
22%. The model parameters are from Clague & Frey (1982, table
5). The initial concentrations for Th, La and Sm are 02, 267 and
071 ppm, respectively. The D for Th, La and Sm are 00025, 0008
and 0047, respectively. The P values for Th, La and Sm are 0038,
0012 and 0071, respectively. Each symbol indicates an increment of
2% melting.
for batch and accumulated fractional melts for the
range of 1±22% melting. Over this range the trends
for both melting models are very similar for 1/La vs
1/Th whereas for 1/Sm vs 1/Th, they differ significantly
at higher extents of melting. Therefore, for inversion
calculations we emphasize highly incompatible elements because they are insensitive to melting models.
However, using this approach to constrain residual
phases requires robust information on the partition
coefficients (D) of these elements. At this time, the
experimentally determined D values for highly incompatible elements in mantle phases vary by large factors,
more than a factor of 10 [e.g. the difference in D0LREE
between Blundy et al. (1998) and Salters & Longhi
(1999)]. The effect of this uncertainty on the estimated
mineral proportions is addressed.
Estimating the proportions of clinopyroxene and
garnet in sources
An important objective is to evaluate the role of clinopyroxene and garnet in the sources of lavas forming the
North Arch and Honolulu Volcanics. Garnet lherzolite
has been proposed as the source for the Honolulu
Volcanics (Clague & Frey, 1982) and North Arch
(Frey et al., 2000), but recent Os isotopic data have
been used to argue that pyroxenite forms an important
part of the source of Honolulu Volcanics (Lassiter et al.,
2000). During melting of anhydrous garnet lherzolite
and pyroxenite the abundances of incompatible
elements are dominantly controlled by residual clinopyroxene and garnet, which are more abundant in
pyroxenite than in peridotite. Here, we use the
inversion of batch melting equation [equation (6) in
Appendix B] to determine the bulk partition coefficients of LREE (D0LREE ), which are then used to infer
proportions of clinopyroxene and garnet in the source.
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JOURNAL OF PETROLOGY
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For this approach to be valid, there are several
requirements. First, primary melt compositions must
be estimated; second, the isotopic and major element
characteristics of the lavas must be consistent with
derivation from a common source; third, the mineral
assemblage in the source must remain essentially
unchanged during melting so that Px and Py in equation (5) of Appendix B are constant or much less than
unity; fourth, the samples must be evenly distributed
over a range of 1/x to ensure that the regression analysis
is statistically meaningful. Based on their variations in
trace element abundance ratios, Group A North Arch
lavas and the seven lavas from the Honolulu Volcanics
with Th content >5 ppm meet these requirements.
Their systematic 1/Th±1/La variations are used for
the inverse calculation.
In addition to the slope (S) and intercept (I) in a 1/x±
1/y plot, four more variables are required to quantify
bulk D0LREE [equation (6) in Appendix B]. For mantle
lithology, PTh and PLREE (see Appendix B for notations) are 1; therefore, they can be ignored. Consequently, the major sources of uncertainties are
D0Th and C0Th . Bulk D0Th is dominated by clinopyroxene
cpx=melt
and garnet. The experimentally determined DTh
varies from 00013 to 0036, with most data within a
range of 001±0014 (LaTourrette & Burnett, 1992;
Beattie, 1993a, 1993b; Hauri et al., 1994; Lundstrom
et al., 1998; van Westrenen et al., 2000; Landwehr et al.,
2001). For melts that equilibrated with both clinopyrgt=melt
cpx=melt
oxene and garnet, DTh
is lower than DTh
and
ranges from 00013 to 00033 (LaTourrette & Burnett,
1992; Beattie, 1993a, 1993b; LaTourrette et al., 1993;
Hauri et al., 1994). In contrast, Salters & Longhi
(1999) used their experimental data to derive a lower
cpx=melt
gt=melt
DTh
of 0006 and a higher DTh
of 0008 for lowdegree melting of garnet peridotite. They argued, on
the basis of major element composition of the bulk
system, that the partition coefficients determined from
their experiments are suitable for peridotite and those
from previous experiments are most applicable to
garnet pyroxenite and eclogite. Consequently, we
infer that the range of bulk DTh
0 varies from 0009 for
pyroxenite (70% clinopyroxene ‡ 30% garnet) to
0002 for peridotite (25% clinopyroxene ‡ 10%
garnet). This value for garnet peridotite is very similar
to those calculated (00022) by Landwehr et al.
(2001, table 4). With this range of DTh
0 , the Th contents
in the primary North Arch Group A lavas can be
derived by 4% melting from primitive mantle (PM)
or 8±14% melting from enriched mantle with a Th
concentration three times PM value. Higher Th
content in the source, for example four times PM,
requires 12±18% melting, which is unlikely for these
highly alkalic lavas. With constraints of DTh
0
(0002±0009) and CTh
(1±3 times PM value), we
0
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Fig. 8. Plot of 1/Th vs 1/La for North Arch Group A lavas and the
nephelinite and nepheline melilitites from the Honolulu Volcanics.
The abundances of Th, La and Ce are corrected for olivine fractionation. Also indicated are regression lines through the two groups of
lavas with the linear equations and R2 labelled.
then calculated bulk DLa
using the slopes and
0
intercepts in the 1/Th±1/La plot.
In a 1/Th±1/La plot, Group A North Arch lavas
form a trend with intercept/slope ratio (I/S) of 0093
(Fig. 8). If the source of these lavas has a C0Th of
0085±026 ppm (1±3 times the PM value) and a DTh
0
of 0002±0009 as we inferred above, the bulk DLa
0 in
this source can vary from 0011 to 0034 based on
equation (6) in Appendix B (stippled area in Fig. 9a).
cpx=melt
Using a DLa
of 008 (Blundy et al., 1998) and a
gt=melt
DLa
of 00164 (Hauri et al., 1994), this range of
bulk DLa
corresponds to 10±35% clinopyroxene in
0
the source if the clinopyroxene/garnet ratio is two
cpx=melt
(Fig. 9b). A lower DLa
of 0054 from Hart &
Dunn (1993) increases the clinopyroxene proportion
to 15±55% depending on the clinopyroxene/garnet
ratios (Fig. 9b). Because the bulk D0La is dominated
gt=melt
by Dcpx=melt
, variation in DLa
causes only 55%
La
difference in clinopyroxene proportion estimates. The
cpx=melt
DLa
and Dgt=melt
from Salters & Longhi (1999) are
La
50012, which are too low to account for the bulk D0La
(0011±0034). These estimated clinopyroxene and
garnet modes extend to higher than those in typical
garnet peridotite, but not as high as those in garnet
pyroxenite. Therefore, the source of Group A North
Arch lavas is inferred to be a mixture of peridotite and
garnet pyroxenite.
Compared with Group A North Arch lavas, the
seven Honolulu samples with Th contents 45 ppm
define a much lower I/S ratio in a 1/Th±1/La plot
(Fig. 8; 0093 vs 00081). Because of the low I/S ratio,
the bulk D0La is insensitive to the C0Th term and is
dominated by only the D0Th term [equation (6) in
Appendix B]. Because a D0Th ranging from 0002 to
0009 leads to a bulk D0La of 0004±0012 (Fig. 9c), the
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YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
La
Fig. 9. (a) Bulk DTh
0 vs bulk D0 calculated for the source of North Arch lavas using inversion of batch melting [Appendix B, equation (6)].
The Th content in the source is considered to be 1±3 times the primitive mantle value (0085) and the range of bulk DTh
0 is estimated to be
La
within 0002±0009 (see text for derivation of these ranges). The stippled area indicates the range of bulk DTh
0 and corresponding bulk D0
(0011±0034) estimated for the source of North Arch lavas. (b) Calculated bulk DLa
for
the
source
of
North
Arch
lavas
vs
clinopyroxene
%
0
Th
La
(cpx%) estimated from the published DLa
0 for cpx and garnet (gt) using various cpx/gt ratios. (c) Bulk D0 vs bulk D0 calculated for the
source of the Honolulu Volcanic field using inversion of batch melting [Appendix B, equation (6)]. The stippled area indicates the range of
La
La
bulk DTh
0 and corresponding bulk D0 estimated for the source of the Honolulu Volcanics. (d) Calculated bulk D0 (0004±0012) for the
and
cpx/gt
ratios
used
to
calculate
the
lower
dash
and dot lines are as
source of the Honolulu Volcanic field vs required cpx%. The DLa
0
indicated in (b).
source of Honolulu lavas contains 5±20% of clinopyrcpx=melt
oxene based on a DLa
of 005±008 (Fig. 9d).
Varying clinopyroxene/garnet ratio from one to three
causes only 52% difference in the estimates for
cpx=melt
clinopyroxene proportion (Fig. 9d). The low DLa
gt=melt
and DLa
from Salters & Longhi (1999) require
30±90% clinopyroxene. Although the literature data
cpx=melt
gt=melt
for DLa
and DLa
result in a large variation in
the proportion of clinopyroxene (Fig. 9c and d), most
cpx=melt
gt=melt
of the data for DLa
and DLa
indicate that the
source of North Arch lavas contains 10±55% clinopyroxene and 5±25% garnet whereas that of
Honolulu lavas has only 5±20% clinopyroxene and
5±8% garnet. This result is consistent with the inference from the Tb/Yb vs Th trend (Fig. 6a) that garnet
was a more significant phase in the residue for North
Arch lavas, and supports the conclusions of Clague &
Frey (1982) and Frey et al. (2000) that another residual
phase, such as olivine, is required for the source of
Honolulu Volcanics and North Arch lavas.
Isotopic and compositional constraints
on the sources of lavas forming
North Arch and Honolulu Volcanics
Evaluating previous models
The low 87 Sr/86 Sr and high 143 Nd/144 Nd ratios in the
Hawaiian North Arch and rejuvenated-stage lavas
require derivation from a long-term depleted source.
However, these lavas are relatively enriched in
incompatible elements; i.e. they have high Rb/Sr and
low Sm/Nd ratios compared with the tholeiitic
basalts that form the Hawaiian shields. This apparent
contradiction can be explained by three alternative
models: (1) mixing between melts derived from
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JOURNAL OF PETROLOGY
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enriched and depleted sources (Chen & Frey, 1985;
Reiners, 2002); (2) extremely small extents of melting
from depleted mantle sources (Frey & Roden, 1987;
Sims et al., 1995); (3) larger extents of melting from a
recently enriched source (Roden et al., 1984; Chen &
Frey, 1985; Clague & Dalrymple, 1988; Class et al.,
1998; Reiners & Nelson, 1998; Sims et al., 1999; Frey
et al., 2000).
The observed linear correlations between abundances of incompatible elements (Fig. 2) could be
explained by mixing between high-degree and lowdegree melts from depleted mantle or mixing between
melts derived from enriched and depleted sources
(Reiners & Nelson, 1998; Lassiter et al., 2000). In
North Arch lavas, however, the trends defined by mixing the extreme end-members of Groups A and B are
nearly linear in K/Ce±Ce, Ba/La±Th and Nb/La±Th
plots; these linear trends do not explain the different
trends defined by Group A and B North Arch lavas
(Fig. 4a). The absence of linear trends in Th vs Ti, Zr
and Nb plots for the Honolulu Volcanics also argues
against melt mixing (Fig. 2b). In addition, mixing
between alkali basalt and nepheline melilitite from the
Honolulu Volcanics forms a curve in the Th±Ti/Eu
plot that is inconsistent with the linear array defined
by lavas (Fig. 6b).
The major difference between the models (2) and (3)
is source composition, depleted or enriched in incompatible elements. Using the inversion approach based
on the batch melting model, we infer an enriched
source. Equation (3) in Appendix B indicates that the
abundance ratio of two highly incompatible elements
in the source, x/y, is approximated as the slope in the
1/x±1/y plot using lava compositions. This approach
results in a La/Ce ratio of 047 for the sources of
North Arch and Honolulu Volcanics. Clague & Frey
(1982) reached a similar conclusion for the source of
the Honolulu Volcanics using x±x/y plots. The inferred
La/Ce ratio of 047 is significantly higher than the
primitive mantle value (0387) and is consistent with
an enriched source. Watson (1993) and Zou & Zindler
(1996) applied different inversion approaches using all
REE and they concluded that an enriched source was
required for the source of the Honolulu Volcanics.
Moreover, extremely low extents of melting
[model (2)] result in non-linear variations between
abundances of two incompatible elements rather than
the observed linear trends (Reiners & Nelson, 1998;
Frey et al., 2000). Consequently, neither melting trajectories in x±y plots nor inferred source compositions
favor model (2), derivation from a depleted source by
small extents of melting. As a result, model (3), variable extent of melting from an enriched source, is the
best model for generation of rejuvenated-stage and
North Arch lavas.
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Characteristics of the enriched source: constraints
from the relationship between 87 Sr/86 Sr ratios and
abundance ratios of incompatible elements
Two types of enriched mantle have been proposed for
Hawaiian rejuvenated-stage lavas: (1) addition of lowdegree melts from depleted mantle into an enriched
source; (2) addition of low-degree melts from an
enriched source into depleted mantle. Distinguishing
between these two models is important. Is the major
melting regime in the depleted mantle or the enriched
mantle plume (Class & Goldstein, 1997)? If melting
occurred in depleted mantle, what was the enriched
componentÐmantle plume, E-MORB or non-plume
metasomatic agent? If a mantle plume, most probably
the Hawaiian plume, is the main source, why do these
lavas have near-MORB isotopic signatures? To investigate these two types of enriched sources, we first
identify the mixing end-members based on lava
compositions, and then model the two types of metasomatized sources using mixing calculations. An
appropriate source is determined by comparison
between calculated and observed 87 Sr/86 Sr ratios and
abundance ratios of incompatible elements.
In a 87 Sr/86 Sr vs 143 Nd/144 Nd plot, North Arch and
rejuvenated-stage lavas plot between the fields for East
Pacific Rise MORB and Hawaiian shield lavas, consistent with mixing between depleted mantle and a
more enriched component (e.g. Lassiter et al., 2000,
Fig. 1). We assume that the depleted component is
similar to the source of MORB, but we note that
Kani et al. (2000) inferred from Sr±Pb isotopic correlations that the depleted component in North Arch lavas
differs from the source of Pacific MORB. The
geochemical characteristics of MORB sources are relatively well constrained. In contrast, the composition of
the enriched component is an issue of debate. The
Hawaiian plume, a Cretaceous mantle plume, primitive mantle, enriched lithospheric mantle and carbonatitic melts have been proposed (Chen & Frey, 1985;
Clague & Dalrymple, 1988; Salters & Zindler, 1995;
Class & Goldstein, 1997; Reiners & Nelson, 1998; Frey
et al., 2000; Lassiter et al., 2000). For example, Salters
& Zindler (1995) speculated that carbonatite metasomatism may occur in the Hawaiian lithosphere, based
on relative Zr and Ti depletion in clinopyroxenes from
mantle xenoliths from Salt Lake Crater, a vent of the
Honolulu Volcanics. Although some carbonatitic melts
have Ba/Th 4150, they are also characterized by
depletion in Nb relative to La (i.e. Nelson et al., 1988;
Hauri et al., 1993; Ionov et al., 1993; Toyoda et al.,
1994). The high Nb/La ratios of North Arch lavas
(Fig. 4a) are inconsistent with control by carbonatite.
Incompatible element abundance ratios of North
Arch and rejuvenated-stage lavas, in particular, the
618
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
Fig. 10. (a) Ba/Th vs Sr/Nd for Hawaiian and other OIB lavas. The data sources are indicated in the legend. The field encloses Hawaiian
lavas, except for one Honolulu Volcanics sample, which has an unusually high Ba content. PM indicates the value for primitive mantle. The
stars are averages of N-MORB and E-MORB from the compilation of Sun & McDonough (1989). All Hawaiian lavas have Ba/Th 4110,
except for some North Arch and Honolulu Volcanics lavas, which equilibrated with phlogopite and/or amphibole (see discussion in text).
(b) A Nb/Y vs Zr/Y discrimination plot proposed by Fitton et al. (1997) to distinguish MORB from lavas derived from the Icelandic plume
(the shaded area). The Hawaii data lead to two important observations: (1) Hawaiian shields straddle the lower boundary line, perhaps
because the source of geochemically extreme shields, such as Koolau, contained a sedimentary component; (2) lavas from the North Arch and
Honolulu Volcanics straddle the upper boundary overlapping with Icelandic lavas and are distant from the MORB field.
unusually high Ba/Th (110±200 compared with 822
for primitive mantle; see Fig. 10) enable us to identify
the enriched source component. The systematic
decrease in Ba/Th with increasing Th content reflects
the control of phlogopite at low extents of melting and
suggests that the high Ba/Th ratios at high extents
of melting (low Th content) are source characteristics
(Fig. 6a). Most OIB have Ba/Th 5100, but most
Hawaiian and Icelandic lavas have Ba/Th 4100
(Fig. 10a). Normal MORB typically have Ba/Th
ratio lower than the chondritic value (i.e. Hofmann,
1988; Niu et al., 1999; Meurer et al., 2001). Also, the
E-MORB average of Sun & McDonough (1989) has a
Ba/Th of 95. More recent analyses of E-MORB and
near ridge seamounts (M
uhe et al., 1997; Niu & Batiza,
1997) also yield Ba/Th ratios (5100), consistent with
this average. Although six of the 24 E-MORB samples
from the East Pacific Rise analyzed by Niu et al. (1999)
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Table 3: Source compositions (in ppm) and partition coefficients for the modeling compositions
of incipient melts from the depleted mantle (DM) lithosphere and Hawaiian mantle plume
DM lithosphere1
Hawaiian plume2
Dcpx=melt
gt=melt
D
La
Ce
Sr
Nd
0.110
1.37
0.337
3.37
0.49
2.17
0.0493
0.00163
0.0703
0.0053
6.95
35.9
0.0953
0.0025
3
0.1783
0.0523
Ba
0.262
12.4
0.00074
0.0003
Th
0.005
0.106
0.0085
0.0025
1
The compositions of the depleted mantle lithosphere are equivalent to a residue after extraction of 3% MORB melt. This
composition is chosen to represent the chemical characteristics of the bottom of the lithosphere, where plume±lithosphere
interaction is most likely to occur.
2
Based on the LREE-enriched REE patterns in the Hawaiian shield lavas, the La, Ce, Sr and Nd contents in the Hawaiian
plume are inferred to be 2.0, 1.9, 1.7 and 1.6 the primitive mantle values (Sun & McDonough, 1989), respectively. The
Ba and Th contents are inferred from the average Ba/La and La/Th ratios in shield lavas. Melting 10±15% of such a source
will generate Hawaiian shield lavas (Feigenson et al., 1996).
3
Partition coefficients from Johnson (1998).
4
Partition coefficients from Hart & Dunn (1993).
5
See text for the discussion on the partition coefficient of Th.
have Ba/Th ratios 4110, they suggested that these
samples contain a Hawaiian plume component. The
rarity of high Ba/Th ratios (>100) in OIB and MORB
suggests that high Ba/Th is a unique characteristic of
the Hawaiian and Icelandic plumes. Consequently, the
high Ba/Th ratios in North Arch and rejuvenatedstage lavas indicate that the enriched component in
the sources of these lavas was the Hawaiian plume. A
Nb/Y vs Zr/Y plot, which has been used to distinguish
plume and MORB lavas (Fitton et al., 1997), also
indicates that North Arch and rejuvenated-stage
lavas contain a plume component (Fig. 10b).
The relationships between 87 Sr/86 Sr and Ba/Th,
Sr/Nd and La/Ce ratios can further constrain the role
of the Hawaiian plume and depleted mantle in formation of the metasomatized source. Two possible mixing
processes are evaluated: (1) addition of incipient melt
(52%) of depleted mantle to the Hawaiian plume;
(2) addition of incipient melt (52%) of the Hawaiian
plume to depleted mantle. For modeling these processes we assume that: (1) the depleted component is
lithospheric mantle with a 87 Sr/86 Sr ratio of 07025,
whose incompatible element contents are those of a
residue formed after extraction of a 3% MORB melt;
(2) the enriched plume component has a 87 Sr/86 Sr ratio
of 07036, a value typical of Hawaiian shield lavas
(i.e. Stille et al., 1983, 1986; Tatsumoto et al., 1987;
Chen et al., 1991; Garcia et al., 1993; Lassiter et al.,
1996; Pietruszka & Garcia, 1999) with abundances of
La, Ce, Sr and Nd in the enriched (plume) source of
20, 19, 17 and 16 times primitive mantle, respectively. The Ba (124 ppm) and Th (0106 ppm) contents are inferred from the average Ba/La and Th/La
ratios in Hawaiian shield lavas. Melting, 10±15%, of
a peridotite source with these abundances will generate
Hawaiian shield lavas (e.g. Feigenson et al., 1996).
Partition coefficients from Johnson (1998), which are
similar to those of many other workers (e.g. Hart &
Dunn, 1993; Hauri et al., 1994; Lundstrom et al., 1998),
were used to calculate the compositions of the incipient
melts (Table 3).
We first evaluate mixing models involving addition
of incipient melts derived from depleted mantle lithosphere to the Hawaiian plume. This model was examined by Chen & Frey (1985) using a La/Ce vs 87 Sr/86 Sr
plot and was favored for the generation of Koloa
Volcanics on Kauai volcano (Clague & Dalrymple,
1988; Reiners & Nelson, 1998). Compared with the
results of Chen & Frey (1985), our calculation shows
lower La/Ce ratios in the mixed source [037±044 in
Fig. 11 compared with 036±055 as given by Chen &
Frey (1985)]. This discrepancy results from the difference in the DLa/DCe ratio between these two models.
Chen & Frey (1985) used a low DLa/DCe of 05 to
obtain higher La/Ce ratios in the incipient melts
(52%) from a MORB source. However, most recent
experimental data result in higher DLa/DCe ranging
from 058 to 070 (e.g. Hart & Dunn, 1993; Hauri
et al., 1994; Lundstrom et al., 1998). Our modeling
shows that a mixed source with 87 Sr/86 Sr ˆ 07031
can explain the Th content inferred for the sources of
North Arch and Honolulu Volcanics lavas, but it cannot explain the high La/Ce, Sr/Nd and Ba/Th ratios
(Fig. 11). Very low extents of melting, 501%, of
depleted mantle lithosphere are required to generate
the high La/Ce, Sr/Nd and Ba/Th ratios in the source
of lavas forming the North Arch and Honolulu
Volcanics.
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YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
Fig. 11. Evaluation of mixing models involving addition of incipient melts of a depleted mantle source (DM) to the plume using 87 Sr/86 Sr vs
La/Ce, Sr/Nd and Ba/Th and Th concentration. The sources of lavas forming the North Arch (NA) and Honolulu Volcanic (HV) are the
labelled filled rectangles (ratios) and the stippled fields for Th. These sources were calculated from inversion of the batch melting equation.
The vertical dotted line emanating from the DM source indicates the trajectory of melts formed by variable amounts of partial melting. The
continuous lines are mixing lines between partial melts derived from DM and the plume source. These lines define a range of possible source
compositions for NA and HV lavas that are created by mixing of incipient melts of a DM source with the plume. Labelled dotted lines
connecting continuous lines indicate mixing proportions. In general, these model sources cannot explain the La/Ce, Sr/Nd and Ba/Th ratios
inferred for NA and HV sources. The partition coefficients and the compositions of plume source and depleted mantle are listed in Table 3.
The olivine:orthopyroxene:clinopyroxene:garnet proportions in source and melt are 055:025:015:005 and ±01:03:04:04, respectively. The
87
Sr/86 Sr ratios are from Roden et al. (1984), Frey et al. (2000) and Lassiter et al. (2000). The Ba/Th ratio for the source of the Honolulu
Volcanics is not plotted because the 1/Th vs 1/Ba plot results in a relatively low correlation coefficient.
In contrast, a mixed source containing 995±98%
depleted mantle lithosphere and 05±2% melt derived
from 2% partial melting of plume source has
87
Sr/86 Sr, Ba/Th, Sr/Nd and La/Ce ratios consistent
with those inferred for the sources of the North Arch
and Honolulu Volcanics lavas (Fig. 12). These lowdegree melts of the plume source might be generated
with residual K-bearing phases, thereby resulting in
depletion of K2O in the mixed source. Residual phlogopite is not expected for melting of high-temperature
plumes (Class & Goldstein, 1997); however, it may
persist during incipient melting of a plume at the
water-saturated solidus (Sato et al., 1997; Wallace,
1998). Therefore, the K2O depletion in Group A
North Arch lavas, which do not have K/Ce and
Rb/Ce variations consistent with residual K-bearing
minerals (Fig. 4a), may reflect K depletion in the
mixed source. This model also gives Th contents ranging from 008 to 020 in the metasomatized source,
which overlaps with our estimate based on the batch
melting equation. Consequently, we favor this model
for generation of North Arch and Honolulu Volcanics
lavas.
The small amount of plume-derived melt, however,
does not explain the relatively high proportion of clinopyroxene (10±55%) and garnet (5±25%) inferred to be
in the source of North Arch lavas. As discussed by
Lassiter et al. (2000), the mantle lithosphere created
at the ridge axis must locally contain pyroxenite, if
extraction of MORB melts is incomplete.
Constraints from Os and Sr isotopic ratios
In contrast to the small variation of 87 Sr/86 Sr ratio
(07030±07034), the 187 Os/188 Os ratio in Hawaiian
rejuvenated-stage lavas varies over a large range of
0134±0175 (Lassiter et al., 2000). Unlike Hawaiian
shield lavas, rejuvenated-stage lavas do not define a
positive 187 Os/188 Os±87 Sr/86 Sr correlation (Hauri et al.,
1996; Lassiter & Hauri, 1998; Lassiter et al., 2000).
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Fig. 12. Evaluation of mixing models involving addition of incipient melts of the plume source to DM using 87 Sr/86 Sr vs La/Ce, Sr/Nd and
Ba/Th and Th concentrations. The approach is similar to that for Fig. 11 except that the continuous mixing lines represent mixing between
DM and incipient melts of the plume. In general, the sources for NA and HV lavas can be created by adding 05±2% of plume-derived melts
(2% melting) to DM.
Eight of 20 rejuvenated-stage samples analyzed by
Lassiter et al. (2000) have higher 187 Os/188 Os ratios
than shield lavas, thereby implying that the Hawaiian
plume alone is not an appropriate source for
rejuvenated-stage lavas. Lassiter et al. (2000) argued
against the involvement of a Hawaiian plume component in the generation of rejuvenated-stage lavas
because these lavas do not fall on calculated mixing
curves between shield lavas and depleted mantle in a
187
Os/188 Os vs 87 Sr/86 Sr plot (see Lassiter et al., 2000,
fig. 5). They proposed that rejuvenated-stage lavas
were derived from a marble-cake lithospheric mantle
with variable proportions of pyroxenite veins in a
lherzolite matrix. With this interpretation the high
187
Os/188 Os ratios in rejuvenated-stage lavas reflect
the contribution from pyroxenite veins, which can
have high 187 Os/188 Os ratio ranging up to six (Reisberg
et al., 1991; Roy-Barman et al., 1996). Lassiter et al.
(2000) suggested that the pyroxenite component
formed near the mid-ocean ridge from E-MORB
melts generated at the limbs of the MORB melting
region. A difficulty with this model is that many
E-MORB do not have sufficiently high 87 Sr/86 Sr ratios
(rejuvenated-stage lavas have ratios of 07030±07034)
even after 100 Myr residence in the oceanic lithosphere. For example, E-MORB from the East Pacific
Rise (Niu et al., 1999) increase their 87 Sr/86 Sr ratios
from 07028 to 07029 after 100 Myr; therefore, a component with a higher 87 Sr/86 Sr ratio is required for the
rejuvenated-stage lavas.
Because of the similarly high Ba/Th and Sr/Nd ratios
in shield and rejuvenated-stage lavas, we have suggested that Hawaiian plume is a suitable component.
We have also demonstrated that the 87 Sr/86 Sr, Ba/Th,
Sr/Nd and La/Ce ratios and Th content in the source of
rejuvenated-stage lavas can be modeled by lithospheric
mantle metasomatized by low-degree melts from the
Hawaiian plume. In our model, the incompatible
element abundances of the metasomatized sources
are dominated by metasomatic agents. In contrast,
we suggest that Os isotopic ratios are controlled by
the marble-cake lithosphere that is heterogeneous in
187
Os/188 Os ratio because of heterogeneous pyroxenite
distribution (Reisberg et al., 1991; Roy-Barman et al.,
1996; Lassiter et al., 2000). The calculated mixing
curves in the 187 Os/188 Os±87 Sr/86 Sr plot (Fig. 13)
show that mixing lithospheric mantle with small
amounts (55%) of plume-derived melt does not
change the 187 Os/188 Os but does increase the 87 Sr/86 Sr
of the lithospheric mantle (Fig. 13). When the proportion of plume-derived component exceeds 5%, the
metasomatized mantle has the 87 Sr/86 Sr ratio of
622
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
(2)
Fig. 13. 187 Os/188 Os vs 87 Sr/86 Sr. The dotted field encloses the data
of Lassiter et al. (2000) for the Honolulu Volcanics. The strong
hyperbolic curves represent mixing between a plume-derived melt
with homogeneous 187 Os/188 Os and 87 Sr/86 Sr ratios (1% melting)
and depleted mantle lithosphere with heterogeneous 187 Os/188 Os
ratio caused by various proportions of pyroxenite. The dashed lines
indicate mixing proportions. The melt has 1240 ppm Sr and 025 ppb
Os. The depleted lithospheric mantle has 9 ppm Sr and 2 ppb Os.
plume-derived melt and its 187 Os/188 Os ratio starts to
approach the value of plume-derived melt (Fig. 13).
The 187 Os/188 Os and 87 Sr/86 Sr ratios of rejuvenatedstage lavas are consistent with derivation from a source
containing 98% depleted lithospheric mantle and 2%
plume-derived melt (Fig. 13). This mixing ratio is
within the range of mixing proportions required to
create the incompatible element abundance ratios
in the source of North Arch lavas and the Honolulu
Volcanics (e.g. La/Ce, Ba/Th and Sr/Nd in Fig. 12).
In these sources formed by mixing, the incompatible
element contents and Sr and Nd isotopic ratios
are dominated by the metasomatic melt, whereas
the 187 Os/188 Os ratio reflects the heterogeneity of the
depleted source caused by varying proportions of
lherzolite and pyroxenite.
CONCLUSIONS
In addition to their alkalic composition, lavas forming
the Hawaiian North Arch and rejuvenated-stage
Honolulu Volcanics are distinct from tholeiitic
Hawaiian shield lavas in their high abundance of
incompatible elements, relatively low 87 Sr/86 Sr and
high 143 Nd/144 Nd ratios, and a large variation in
187
Os/188 Os ratio, which is not correlated with 87 Sr/
86
Sr. The compositional and isotopic variations in
these two alkalic suites of lavas provide important
geochemical constraints on their sources.
(1) The positive Tb/Yb±Th correlation is consistent
with the control of residual garnet. Variations in
(3)
(4)
(5)
Sr/Nd, K/Ce, Ba/La and Ba/Th indicate that
lavas formed by the lowest extents of melting, i.e.
highest Th content, formed in equilibrium with
phlogopite. Also, variations in Ti/Eu, Zr/Sm, Nb/
La and Nb/U indicate that Fe±Ti oxides were
important residual phases, especially for the
Honolulu Volcanics with 45 ppm Th.
Based on inversion of the batch melting equation,
the North Arch lavas with Th contents 53 ppm
were derived from a source with 10±55% clinopyroxene and 5±25% garnet. Compared with that
of North Arch lavas, the source of lavas for the
Honolulu Volcanics with Th contents 45 ppm
contains lower proportions of clinopyroxene
(5±20%) and garnet (5±8%).
The high Nb/Y ratio at a given Zr/Y and the high
Ba/Th ratio (significantly greater than the chondritic value) in lavas from the North Arch and
Honolulu Volcanics indicate that their sources
contain a component derived from the Hawaiian
plume.
Model calculations show that the 87 Sr/86 Sr ratio,
abundance ratios of incompatible elements, such
as La/Ce, Sr/Nd and Ba/Th, and Th contents in
these two suites of lavas can be explained by
derivation from a long-term depleted source
recently enriched by incipient melts (52%)
derived from the Hawaiian plume.
The abundances of incompatible elements in such
a metasomatized mantle are dominated by the
incipient melts. In contrast, the variable isotopic
ratios of Os, an element that is compatible during
mantle melting, reflect heterogeneity, varying
proportions of pyroxenite, in the long-term
depleted source.
ACKNOWLEDGEMENTS
We thank S. Huang, M. Schmitz and B. Grant for their
assistance in ICP-MS analysis. We also gratefully
appreciate reviews by K. Rubin, M. Feigenson,
C. Class and D. Geist, as well as discussions with
J. Lassiter and S. Parmann. This project was supported
by NSF Grant EAR 0105557 to F.A.F. and NSC
Grant 91-2116-M-006-005 to H.-J.Y.
SUPPLEMENTARY DATA
Supplementary data for this paper are available on
Journal of Petrology online.
REFERENCES
Barth, M. G., McDonough, W. F. & Rudnick, R. L. (2000).
Tracking the budget of Nb and Ta in the continental crust.
Chemical Geology 165, 197±213.
623
JOURNAL OF PETROLOGY
VOLUME 44
Beattie, P. (1993a). The generation of uranium series disequilibria
by partial melting of spinel peridotite: constraints from the
partitioning studies. Earth and Planetary Science Letters 117, 379±391.
Beattie, P. (1993b). Uranium±thorium disequilibria and partitioning on melting of garnet peridotite. Nature 363, 63±65.
Blundy, J. D., Robinson, J. A. C. & Wood, B. J. (1998). Heavy REE
are compatible in clinopyroxene on the spinel lherzolite solidus.
Earth and Planetary Science Letters 160, 493±504.
Caroff, M., Maury, R. C., Guille, G. & Cotton, J. (1997). Partial
melting below Tubuai (Austral Islands, French Polynesia).
Contributions to Mineralogy and Petrology 127, 369±382.
Chauvel, C. & Hemond, C. (2000). Melting of a complete section
of recycled oceanic crust: trace element and Pb isotopic
evidence from Iceland. Geochemistry, Geophysics, Geosystems 1,
1999GC000003.
Chen, C.-Y. & Frey, F. A. (1983). Origin of Hawaiian tholeiite and
alkalic basalt. Nature 302, 785±789.
Chen, C.-Y. & Frey, F. A. (1985). Trace element and isotopic
geochemistry of lavas from Haleakala volcano, East Maui,
Hawaii: implications for the origin of Hawaiian lavas. Journal of
Geophysical Research 90, 8743±8768.
Chen, C.-Y., Frey, F. A. & Garcia, M. O. (1990). Evolution of
alkalic lavas at Haleakala Volcano, east Maui, Hawaii. Contributions to Mineralogy and Petrology 105, 197±218.
Chen, C.-Y., Frey, F. A., Garcia, M. O., Dalrymple, G. B. &
Hart, S. R. (1991). The tholeiite to alkalic basalt transition at
Haleakala Volcano, Maui, Hawaii. Contributions to Mineralogy and
Petrology 106, 183±200.
Clague, D. A. & Dalrymple, G. B. (1988). Age and petrology of
alkalic postshield and rejuvenated-state lava from Kauai, Hawaii.
Contributions to Mineralogy and Petrology 99, 202±218.
Clague, D. A. & Dixon, J. E. (2000). Extrinsic controls on the
evolution of Hawaiian ocean island volcanoes. Geochemistry,
Geophysics, Geosystems 1, 1999GC000023.
Clague, D. A. & Frey, F. A. (1982). Petrology and trace element
geochemistry of the Honolulu Volcanics, Oahu: implications for
the oceanic mantle below Hawaii. Journal of Petrology 23, 447±504.
Clague, D. A., Holcomb, R. T., Sinton, J. M., Detrick, R. S. &
Torresan, M. E. (1990). Pliocene and Pleistocene alkalic flood
basalts on the seafloor north of the Hawaiian islands. Earth and
Planetary Science Letters 98, 175±191.
Class, C. & Goldstein, S. L. (1997). Plume±lithosphere interactions
in the ocean basins: constraints from the source mineralogy. Earth
and Planetary Science Letters 150, 245±260.
Class, C., Goldstein, S. L., Altherr, R. & Bachelery, P. (1998). The
process of plume±lithosphere interactions in the ocean basinsÐthe
case of Grande Comore. Journal of Petrology 39, 881±903.
Dalpe, C. & Baker, D. R. (2000). Experimental investigation of
large ion lithophile element, high field strength element and rare
earth element partitioning between calcic amphibole and basaltic
melt: the effects of pressure and oxygen fugacity. Contributions to
Mineralogy and Petrology 140, 233±250.
David, K., Schiano, P. & Allegre, C. J. (2000). Assessment of the Zr/
Hf fractionation in oceanic basalts and continental materials
during petrogenetic processes. Earth and Planetary Science Letters
178, 285±301.
Dixon, J. E., Clague, D. A., Wallace, P. & Poreda, R. (1997).
Volatiles in alkalic basalts from the North Arch volcanic field,
Hawaii: extensive degassing of deep submarine-erupted alkalic
series lavas. Journal of Petrology 38, 911±939.
Feigenson, M. D. (1984). Geochemistry of Kauai volcanics and a
mixing model for the origin of Hawaiian alkalic basalts.
Contributions to Mineralogy and Petrology 87, 109±119.
NUMBER 4
APRIL 2003
Feigenson, M. D., Patino, L. C. & Carr, M. J. (1996). Constraints
on partial melting imposed by rare earth element variations in
Mauna Kea basalts. Journal of Geophysical Research 101, 11815±
11829.
Fitton, J. G., Saunders, A. D., Norry, M. J., Hardarson, B. S. &
Taylor, R. N. (1997). Thermal and chemical structure of the
Iceland plume. Earth and Planetary Science Letters 153, 197±208.
Foley, S. F., Barth, M. G. & Jenner, G. A. (2000). Rutile/melt
partition coefficients for trace elements and an assessment of the
influence of rutile on the trace element characteristics of subduction zone magmas. Geochimica et Cosmochimica Acta 64, 933±938.
Francis, D. & Ludden, J. (1995). The signature of amphibole in
mafic alkaline lavas, a study in the Northern Canadian
Cordillera. Journal of Petrology 36, 1171±1191.
Frey, F. A. & Roden, M. F. (1987). The mantle source for the
Hawaiian islands: constraints from the lavas and ultramafic
inclusions. In: Menzies, M. A. & Hawkesworth, C. J. (eds) Mantle
Metasomatism. London: Academic Press, pp. 423±463.
Frey, F. A., Wise, W. S., Garcia, M. O., West, H., Kwon, S.-T. &
Kennedy, A. (1990). Evolution of Mauna Kea Volcano, Hawaii:
petrologic and geochemical constraints on postshield volcanism.
Journal of Geophysical Research 95, 1271±1300.
Frey, F. A., Garcia, G. A. & Roden, M. F. (1994). Geochemical
characteristics of Koolau Volcano: Implications of intershield
geochemical differences among Hawaiian volcanoes. Geochimica et
Cosmochimica Acta 58, 1441±1462.
Frey, F. A., Clague, D. A., Mahoney, J. J. & Sinton, J. M. (2000).
Volcanism at the edge of Hawaiian plume: petrogenesis of
submarine alkalic lavas from the North Arch volcanic field.
Journal of Petrology 41, 667±691.
Garcia, M. O., Rhodes, J. M., Wolfe, E. W., Ulrich, G. E. &
Ho, R. A. (1992). Petrology of lavas from episodes 2±47 of the
Puu Oo eruption of Kilauea volcano: evaluation of magmatic
processes. Bulletin of Volcanology 55, 1±16.
Garcia, M. O., Jorgenson, B. A., Mahoney, J. J., Ito, E. &
Irving, A. J. (1993). An evaluation of temporal geochemical
evolution of Loihi summit lavas: results from Alvin submersible
dives. Journal of Geophysical Research 98, 537±550.
Garcia, M. O., Foss, D. J. P., West, H. B. & Mahoney, J. J. (1995).
Geochemical and isotopic evolution of Loihi volcano, Hawaii.
Journal of Petrology 36, 1647±1674.
Garcia, M. O., Rhodes, J. M., Trusdell, F. A. & Pietruszka, A. J.
(1996). Petrology of lavas from the Puu Oo eruption of Kilauea
Volcano: III. The Kupaianaha episode (1986±1992). Bulletin of
Volcanology 58, 359±379.
Hart, S. R. & Dunn, T. (1993). Experimental cpx/melt partitioning
of 24 trace elements. Contributions to Mineralogy and Petrology 113, 1±8.
Hauri, E. H., Shimizu, N., Dieu, J. J. & Hart, S. R. (1993).
Evidence for hotspot-related carbonatite metasomatism in the
oceanic upper mantle. Nature 365, 221±227.
Hauri, E. H., Wagner, T. P. & Grove, T. L. (1994). Experimental
and natural partitioning of Th, U, Pb and other trace elements
between garnet, clinopyroxene and basaltic melts. Chemical Geology
117, 149±166.
Hauri, E. H., Lassiter, J. C. & DePaolo, D. J. (1996). Osmium
isotope systematics of drilled lavas from Mauna Loa, Hawaii.
Journal of Geophysical Research 101, 11793±11806.
Hofmann, A. W. (1988). Chemical differentiation of the Earth: the
relationship between mantle, continental crust, and oceanic crust.
Earth and Planetary Science Letters 90, 297±314.
Hofmann, A. W. & Feigenson, M. D. (1983). Case studies on the
origin of basalt. I. Theory and reassessment of Grenada basalts.
Contributions to Mineralogy and Petrology 84, 382±389.
624
YANG et al.
SOURCE COMPONENTS OF HAWAIIAN LAVAS
Hofmann, A. W., Feigenson, M. D. & Raczek, I. (1984). Case
studies on the origin of basalt. III. Petrogenesis of the Mauna Ulu
eruption Kilauea, 1969±1971. Contributions to Mineralogy and
Petrology 88, 24±35.
Hofmann, A. W., Jochum, K. P., Seufert, M. & White, W. M.
(1986). Nb and Pb in oceanic basalts: new constraints on mantle
evolution. Earth and Planetary Science Letters 79, 33±45.
Huang, S. & Frey, F. A. (2003). The trace element abundances of
Mauna Kea basalt from phase 2 of the Hawaii Scientific Drilling
Project: petrogenetic implications of correlations with major
element content and isotopic ratios. Geochemistry, Geophysics,
Geosystems (in press).
Ionov, D. A., Dupuy, C., O'Reilly, S. Y., Kopylova, M. G. &
Genshaft, Y. S. (1993). Carbonated peridotite xenoliths from
Spitsbergen: implications for trace element signature of mantle
carbonate metasomatism. Earth and Planetary Science Letters 119,
283±297.
Johnson, K. T. M. (1998). Experimental determination of partition
coefficients for rare earth and high-field-strength elements
between clinopyroxene, garnet, and basaltic melt at high
pressures. Contributions to Mineralogy and Petrology 133, 60±68.
Kani, T., Uto, K., Clague, D. A., & Naka, J. (2000). Isotopic study
for alkalic lavas from the North Arch Volcanic Field, Hawaii.
EOS Transactions, American Geophysical Union, Western Geophysics
Meeting 81, 256.
Kinzler, R. J. (1997). Melting of mantle peridotite at pressures
approaching the spinel to garnet transition: application to midocean ridge basalt petrogenesis. Journal of Geophysical Research 102,
853±874.
Landwehr, D., Blundy, J., Chamorro-Perez, E. M., Hill, E. &
Wood, B. (2001). U-series disequilibria generated by partial melting
of spinel lherzolite. Earth and Planetary Science Letters 188, 329±348.
Langmuir, C. H., Klein, E. M. & Plank, T. (1992). Petrological
systematics of mid-ocean ridge basalts: constraints on melt
generation beneath ocean ridges. In: Phipps Morgan, J.,
Blackman, D. K. & Sinton, J. M. (eds) Mantle Flow and Melt
Generation at Mid-Ocean Ridges. Geophysical Monograph, American
Geophysical Union 71, 183±280.
Lanphere, M. A. & Dalrymple, G. B. (1980). Age and strontium
isotopic composition of the Honolulu Volcanic Series, Oahu,
Hawaii. American Journal of Sciences 280-A, 736±751.
Lassiter, J. C. & Hauri, E. H. (1998). Osmium-isotope variations
in Hawaiian lavas: evidence for recycled oceanic lithosphere in
the Hawaiian plume. Earth and Planetary Science Letters 164,
483±496.
Lassiter, J. C., Depaolo, D. J. & Tatsumoto, M. (1996). Isotopic
evolution of Mauna Kea volcano: results from the initial phase of
the Hawaii Scientific Drilling Project. Journal of Geophysical
Research 101, 11769±11780.
Lassiter, J. C., Hauri, E. H., Reiners, P. W. & Garcia, M. O. (2000).
Generation of Hawaiian post-erosional lavas by melting of a
mixed lherzolite/pyroxenite source. Earth and Planetary Science
Letters 178, 269±284.
LaTourrette, T. Z. & Burnett, D. S. (1992). Experimental
determination of U partitioning and Th partitioning between
clinopyroxene and natural and synthetic basaltic liquid. Earth and
Planetary Science Letters 110, 227±244.
LaTourrette, T. Z., Kennedy, A. K. & Wasserburg, G. J. (1993).
Thorium±uranium fractionation by garnet: evidence for a deep
source and rapid rise of oceanic basalts. Science 261, 739±742.
LaTourrette, T. Z., Hervig, R. L. & Holloway, J. R. (1995). Trace
element partitioning between amphibole, phlogopite, and basanite melt. Earth and Planetary Science Letters 135, 13±30.
Lundstrom, C. C., Shaw, H. F., Ryerson, F. J., Williams, Q. &
Gill, J. (1998). Crystal chemical control of clinopyroxene±melt
partitioning in the Di±Ab±An system: implications for elemental
fractionations in the depleted mantle. Geochimica et Cosmochimica
Acta 62, 2849±2862.
McCallum, I. S. & Charette, M. P. (1978). Zr and Nb partition
coefficients: implications for the genesis of mare basalts,
KREEP, and sea floor basalts. Geochimica et Cosmochimica Acta 42,
859±869.
McKay, G. A., Wagstaff, J. & Yang, S.-R. (1986). Zirconium,
halfnium, and rare earth element partition coefficients for ilmenite
and other minerals in high-Ti lunar mare basalts: an experimental
study. Proceeding 16th Lunar and Planetary Science Conference. Journal of
Geophysical Research 91, Supplement, D229±D237.
Meurer, W. P., Sturm, M. A., Klein, E. M. & Karson, J. A. (2001).
Basalt compositions from the Mid-Atlantic Ridge at SMARK
area (23 300 N to 22 500 N)Ðimplications for parental liquid
variability at isotopically homogeneous spreading centers. Earth
and Planetary Science Letters 186, 451±469.
Minster, J. F. & Allegre, C. J. (1978). Systematic use of trace
elements in igneous processes. Part III: Inverse problem of batch
melting in volcanic suites. Contributions to Mineralogy and Petrology
68, 37±52.
M
uhe, R., Bohrmann, H., Garbe-Sch
onberg, D. & Kassens, H.
(1997). E-MORB glasses from the Gakkel Ridge (Arctic Ocean)
at 87 N: evidence for the Earth's most northerly volcanic activity.
Earth and Planetary Science Letters 152, 1±9.
Nelson, D. R., Chivas, A. R., Chappell, B. W. & McCulloch, M. T.
(1988). Geochemical and isotopic systematics in carbonatites and
implications for the evolution of ocean-island sources. Geochimica et
Cosmochimica Acta 52, 1±17.
Nielsen, R. L., Gallahan, W. E. & Newberger, F. (1992). The
partitioning of Sc, Y, and the REE between olivine, low-Ca
pyroxene, ilmenite, magnetite and natural silicate magmas.
Contributions to Mineralogy and Petrology 110, 488±499.
Niu, Y. & Batiza, R. (1997). Trace element evidence from
seamounts for recycled oceanic crust in the Eastern Pacific
mantle. Earth and Planetary Science Letters 148, 471±483.
Niu, Y., Collerson, K. D., Batiza, R., Wendt, J. I. & Regelous, M.
(1999). Origin of enriched-type mid-ocean ridge basalt at
ridges far from mantle plume. Journal of Geophysical Research 104,
7067±7087.
Pearce, J. A. & Norry, M. J. (1979). Petrogenetic implications of Ti,
Zr, Y, and Nb variations in volcanic rocks. Contributions to
Mineralogy and Petrology 69, 33±47.
Philpotts, J. A., Schnetzler, C. C. & Thomas, H. M. (1972).
Petrogenetic implications of some new geochemical data on
eclogitic and ultrabasic inclusions. Contributions to Mineralogy and
Petrology 36, 1131±1166.
Pietruszka, A. J. & Garcia, M. O. (1999). A rapid fluctuation in the
mantle source and melting history of Kilauea volcano inferred
from the geochemistry of its historical summit lavas. Journal of
Petrology 40, 1321±1342.
Reiners, P. W. (2002). Temporal±compositional trends in intraplate
basalt eruptions: implications for mantle heterogeneity and
melting processes. Geochemistry, Geophysics, Geosystems 3, U1±U30.
Reiners, P. W. & Nelson, B. K. (1998). Temporal±compositional±
isotopic trends in rejuvenated-stage magmas of Kauai, Hawaii,
and implications for mantle melting process. Geochimica et
Cosmochimica Acta 62, 2347±2368.
Reisberg, L. C., Allegre, C. J. & Luck, J.-M. (1991). The Re±Os
systematics of the Ronda ultramafic complex of southern Spain.
Earth and Planetary Science Letters 105, 196±213.
625
JOURNAL OF PETROLOGY
VOLUME 44
Reynolds, R. W. & Geist, D. J. (1995). Petrology of lavas from
Sierra Negra volcano, Isabela Island, Gal
apagos archipelago.
Journal of Geophysical Research 100, 24537±24553.
Rhodes, J. M. (1996). Geochemical stratigraphy of lava flows
sampled by the Hawaii Scientific Drilling Project. Journal of
Geophysical Research 101, 11729±11746.
Rhodes, J. M. & Hart, S. R. (1996). Episodic trace element and
isotopic variations in historical Mauna Loa lavas: implications for
magma and plume dynamics. In: Rhodes, J. M. & Lockwood, J. P.
(eds) Mauna Loa Revealed. Geophysical Monograph, American
Geophysical Union 92, 263±288.
Roden, M. F., Frey, F. A. & Clague, D. A. (1984). Geochemistry of
tholeiitic and alkalic lavas from the Koolau Range, Oahu,
Hawaii: implications for Hawaiian volcanism. Earth and Planetary
Science Letters 69, 141±158.
Roy-Barman, M., Luck, J.-M. & Allegre, C. J. (1996). Os isotopes
in orogenic lherzolite massifs and mantle heterogeneities. Chemical
Geology 130, 55±64.
Rudnick, R. L. & Fountain, D. M. (1995). Nature and composition
of the continental crustÐa lower crustal perspective. Reviews of
Geophysics 33, 267±309.
Salters, V. J. M. & Longhi, J. (1999). Trace element partitioning
during the initial stages of melting beneath mid-ocean ridges.
Earth and Planetary Science Letters 166, 15±30.
Salters, V. J. M. & Zindler, A. (1995). Extreme 176 Hf/177 Hf in the
sub-oceanic mantle. Earth and Planetary Science Letters 129, 13±30.
Sato, K., Katsura, T. & Ito, E. (1997). Phase relations of natural
phlogopite with and without enstatite up to 8 GPa: implication
for mantle metasomatism. Earth and Planetary Science Letters 146,
511±526.
Shimizu, N. & Kushiro, I. (1975). The partitioning of rare earth
elements between garnet and liquid at high pressures: preliminary
experiments. Geophysical Research Letters 2, 413±416.
Sims, K. W. W. & DePaolo, D. J. (1997). Inferences about mantle
magma sources from incompatible element concentration ratios in
oceanic basalts. Geochimica et Cosmochimica Acta 61, 765±784.
Sims, K. W. W., DePaolo, D. J., Murrell, M. T., Baldridge, W. S.,
Goldstein, S. J. & Clague, D. A. (1995). Mechanism of magma
generation beneath Hawaii and mid-ocean ridges: uranium±
thorium and samarium/neodymium isotopic evidence. Science 267,
508±512.
Sims, K. W. W., DePaolo, D. J., Murrell, M. T., Baldridge, W. S.,
Goldstein, S. J., Clague, D. A. & Jull, M. (1999). Porosity of the
melting zone and variations in the solid mantle upwelling rate
beneath Hawaii: inferences from 238 U±230 Th±226 Ra and 235 U±
231
Pa disequilibria. Geochimica et Cosmochimica Acta 63, 4119±4138.
Spath, A., le Roex, A. P. & Duncan, R. A. (1996). The
geochemistry of lavas from the Comores archipelago, western
Indian Ocean: petrogenesis and mantle source region characteristics. Journal of Petrology 37, 961±991.
Stille, P., Unruh, D. M. & Tatsumoto, M. (1983). Pb, Sr, Nd and
Hf isotopic evidence of multiple sources for Oahu, Hawaii basalts.
Nature 304, 25±29.
NUMBER 4
APRIL 2003
Stille, P., Unruh, D. M. & Tatsumoto, M. (1986). Pb, Sr, Nd and
Hf isotopic constraints on the origin of Hawaiian basalts and
evidence for a unique source. Geochimica et Cosmochimica Acta 50,
2303±2319.
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)
Magmatism in the Ocean Basins. Geological Society, London, Special
Publications 42, 313±345.
Tatsumoto, M., Hegner, E. & Unruh, D. M. (1987). Origin of the
West Maui volcanic rocks inferred from Pb, Sr and Nd isotopes
and a multicomponent model for oceanic basalt. US Geological
Survey Professional Paper 1350, 723±744.
Toyoda, K., Horiuchi, H. & Tokonami, M. (1994). Dupal anomaly
of Brazilian carbonatites: geochemical correlations with hotspots
in the South Atlantic and implications for the mantle source.
Earth and Planetary Science Letters 126, 315±331.
Treuil, M. & Joron, J.-L. (1975). Utilisation des elements hygromagmatophiles pour la simplification de la modelisation quantitative des processus magmatiques. Exemples de L'Afar et de la Dorsale
Medioatlantique. Societa Italiana Mineralogia e Petrologia 31, 125±174.
van Westrenen, W., Blundy, J. D. & Wood, B. J. (1999). Crystalchemical controls on trace element partitioning between
garnet and anhydrous silicate melt. American Mineralogist 84,
838±847.
van Westrenen, W., Blundy, J. D. & Wood, B. J. (2000). Effect of
Fe2 ‡ on garnet±melt trace element partitioning: experiments in
FCMAS and quantification of crystal-chemical controls in
natural systems. Lithos 53, 189±201.
Wallace, P. J. (1998). Water and partial melting in mantle
plumes: inferences from the dissolved H2O concentrations of
Hawaiian basaltic magmas. Geophysical Research Letters 25, 3639±
3642.
Walter, M. J. (1998). Melting of garnet peridotite and the origin of
komatiite and depleted lithosphere. Journal of Petrology 39, 29±60.
Walter, M. J., Sisson, T. W. & Presnall, D. C. (1995). A mass
proportion method for calculating melting reactions and application to melting of model upper mantle lherzolite. Earth and
Planetary Science Letters 135, 77±90.
Watson, S. (1993). Rare earth element inversions and percolation
models for Hawaii. Journal of Petrology 34, 763±783.
White, W. M. & Duncan, R. A. (1996). Geochemistry and
geochronology of the Society Island: new evidence for deep
mantle recycling. In: Basu, A. & Hart, S. R. (eds) Earth Processes:
Reading the Isotopic Code. Geophysical Monograph, American Geophysical
Union 95, 183±206.
Yang, H. J., Frey, F. A., Rhodes, J. M. & Garcia, M. O. (1996).
Evolution of Mauna Kea volcano: inferences from lava compositions recovered in the Hawaii Scientific Drilling Project. Journal of
Geophysical Research 101, 11747±11767.
Zou, H. & Zindler, A. (1996). Constraints on the degree of dynamic
partial melting and source composition using concentration ratios
in magmas. Geochimica et Cosmochimica Acta 60, 711±717.
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SOURCE COMPONENTS OF HAWAIIAN LAVAS
APPENDIX A: COMPARISONS
BETWEEN NEW ICP-MS DATA AND
PREVIOUS ANALYSES BY X-RAY
FLUORESCENCE (XRF) AND INAA
For North Arch samples, with few exceptions our ICPMS data agree with the INAA and XRF analyses of
Frey et al. (2000) within 5% for abundances of Sr, Zr,
La, Nd, Sm, Eu and Hf, and within 10% for Ba and
Lu (Appendix Fig. 1a). Data for other elements in
these two datasets show systematic differences. Compared with the ICP-MS data, the analyses of Frey et al.
(2000) are, in general, higher in Ce and Rb by 1±10%,
lower in Y, Nb, Tb, Yb and Lu by 1±15%, and lower
in Th by 15±25% (Appendix Fig. 1a). As expected,
there are more significant discrepancies between the
ICP-MS data and the older data for the Honolulu
Volcanics reported by Clague & Frey (1982). Specifically, the abundances of Rb, Sr, Zr, Ba, La, Ce, Nd,
Sm, Eu, Tb, Yb, Hf and Ta differ by 10%, with
some exceptions having larger differences of 20%
(Appendix Fig. 1b). In general, the data of Clague &
Frey (1982) are 10±25% lower in Y and Nb and
5±15% lower in Th (Appendix Fig. 1b).
APPENDIX B: DERIVATION FOR
INVERSION OF BATCH MELTING
EQUATION
The equation for non-modal batch melting is
1
CLi
ˆ i
i
D
‡
F…1
ÿ Pi†
C0
0
Appendix Fig. 1.
in x/y vs x plots can be used to infer source characteristics (C0x /C0y ) and partition coefficient (D0y ) provided
that C0x , D0x , Px and Py are constant. This requirement
can be approximated if element x is a highly
incompatible element, such as Th (Clague & Frey,
1982; Hofmann & Feigenson, 1983). Equation (2)
can be rearranged to the form of a 1/xÿ1/y linear
correlation (Sims & DePaolo, 1997):
…1†
where CLi and C0i are concentrations of trace element, i,
in melt and initial source, respectively, D0i is the bulksolid/liquid partition coefficient, F is the extent of melting and P is a bulk-solid/melt partition coefficient
determined by the proportion of phases contributing
to the melt. Treuil & Joron (1975) and Minster &
Allegre (1978) pointed out that the abundance ratio
of two elements x and y can be obtained from (1) by
dividing to eliminate F so that
y
CLx
D0 ÿ Dx0 ……1 ÿ P y †=…1 ÿ P x †† x
C x 1 ÿ Py
CL ‡ 0y
y ˆ
y
CL
C0
C0 1 ÿ P x :
…2†
If D and P for element x and y are constant, CLx /CLy is a
linear function of CLx . Therefore, the linear data array
y
1
D0 ÿ Dx0 ……1 ÿ P y †=…1 ÿ P x ††
C x 1 ÿ Py 1
‡ 0y
:
y ˆ
y
CL
C0
C0 1 ÿ P x CLx
…3†
The intercept (I) and slope (S) are given by
I ˆ
y
D0 ÿDx0 ……1 ÿ P y †=…1 ÿ P x ††
y
C0
…4†
C0x 1 ÿ P y
:
y
C0 1 ÿ P x
…5†
and
Sˆ
Equations (4) and (5) can be combined to eliminate C0y
and obtain
y
1
1 ÿ Py
y
x 1 ÿ P
‡
D
:
…6†
D0 ˆ C0x
0
1 ÿ Px
1 ÿ Px
S
627