EAGE
Basin Research (2014) 26, 621–640, doi: 10.1111/bre.12054
LinkingTarim Basin sea retreat (west China) and
Asian aridification in the late Eocene
R. Bosboom,* G. Dupont-Nivet,*,†,‡ A. Grothe,§ H. Brinkhuis,§,¶ G. Villa,** O. Mandic,††
M. Stoica,‡‡ W. Huang,*,† W. Yang,†,‡ Z. Guo† and W. Krijgsman*
*Paleomagnetic Laboratory Fort Hoofddijk, Faculty of Geosciences, Utrecht University, Utrecht, The
Netherlands
†Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education (Peking University), Beijing,
China
‡Geosciences
Rennes, UMR 6118, Universite de Rennes1, Rennes Cedex, France
§Marine Palynology and Paleoceanography, Laboratory for Palaeobotany and Palynology, Faculty of
Geosciences, Utrecht University, Utrecht, The Netherlands
¶Royal Netherlands Institute for Sea Research, Texel, The Netherlands
**Dipartimento di Scienze della Terra, University of Parma, Parma, Italy
††Geological-Palaeontological Department, Natural History Museum Vienna, Wien, Austria
‡‡Department of Geology and Paleontology,Faculty of Geology and Geophysics, Bucharest University,
Bǎlcescu, Romania
ABSTRACT
The Tarim Basin in western China formed the easternmost margin of a shallow epicontinental sea
that extended across Eurasia and was well connected to the western Tethys during the Paleogene.
Climate modelling studies suggest that the westward retreat of this sea from Central Asia may have
been as important as the Tibetan Plateau uplift in forcing aridification and monsoon intensification
in the Asian continental interior due to the redistribution of the land-sea thermal contrast. However,
testing of this hypothesis is hindered by poor constraints on the timing and precise palaeogeographic
dynamics of the retreat. Here, we present an improved integrated bio- and magnetostratigraphic
chronological framework of the previously studied marine to continental transition in the southwest
Tarim Basin along the Pamir and West Kunlun Shan, allowing us to better constrain its timing,
cause and palaeoenvironmental impact. The sea retreat is assigned a latest Lutetian–earliest Bartonian age (ca. 41 Ma; correlation of the last marine sediments to calcareous nannofossil Zone CP14
and correlation of the first continental red beds to the base of magnetochron C18r). Higher up in the
continental deposits, a major hiatus includes the Eocene–Oligocene transition (ca. 34 Ma). This suggests the Tarim Basin was hydrologically connected to the Tethyan marine Realm until at least the
earliest Oligocene and had not yet been closed by uplift of the Pamir–Kunlun orogenic system. The
westward sea retreat at ca. 41 Ma and the disconformity at the Eocene–Oligocene transition are both
time-equivalent with reported Asian aridification steps, suggesting that, consistent with climate
modelling results, the sea acted as an important moisture source for the Asian continental interior.
INTRODUCTION
During the Cretaceous and Paleogene, a shallow epicontinental sea extended across Eurasia from the Mediterranean Tethys to the Tarim Basin in western China. This
sea is often referred to as the Tarim Sea, Tajik Sea or
Turan Sea (Tang et al., 1992; Burtman & Molnar, 1993;
Burtman, 2000; Bosboom et al., 2011), before it ultimately separated as the Paratethys Sea during the latest
Eocene or early Oligocene (Baldi, 1984; Rusu, 1985; DerCorrespondence: R. Bosboom, Paleomagnetic Laboratory
Fort Hoofddijk, Faculty of Geosciences, Utrecht University,
Budapestlaan 17, 3584 CD Utrecht, The Netherlands.
E-mail: [email protected]
court, 1993; Robinson et al., 1996; R€ogl, 1999; Popov
et al., 2004; Schulz et al., 2005; Vincent et al., 2005;
Allen & Armstrong, 2008). Paleoenvironmental change in
the vast Asian interior has conventionally been attributed
to Tibetan Plateau uplift, as the formation of this geographic barrier likely caused intensification of continentality and the Asian monsoon system (Graham, 1987;
Kutzbach et al., 1989; Ruddiman & Kutzbach, 1989; Prell
& Kutzback, 1992; Sun & Wang, 2005; Kent-Corson
et al., 2009; Boos & Kuang, 2010; Gradstein et al., 2012).
However, recent climate modelling studies show that the
retreat of the proto-Paratethys Sea from Central Asia
would on its own have led to significant aridification and
intensification of the Asian monsoon system by redistribution of land-sea thermal contrasts, providing less
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
621
R. Bosboom et al.
moisture to the Asian interior in the east (Ramstein et al.,
1997; Zhang et al., 2007, 2012). To test these climate
model results, Asian palaeoenvironmental studies provide
evidence for gradual Cenozoic aridification tentatively
linked to Tibetan Plateau uplift, sea retreat or global climate (Garzione et al., 2005; Graham et al., 2005; Sun &
Wang, 2005; Kent-Corson et al., 2009; Bershaw et al.,
2012; Wang et al., 2012). In particular, lacustrine sediments in the Xining Basin along the northeastern margin
of the Tibetan Plateau (Fig. 1) have remarkably accurately recorded the deterioration of global climate during
the Eocene, expressed by stepwise aridification culminating at the ca. 34 Ma Eocene–Oligocene Transition
(EOT; Dupont-Nivet et al., 2007; Abels et al., 2011; R.E.
Bosboom, H.A. Abels, C. Hoorn, B.C.J. van den Berg,
Z. Guo, & G. Dupont-Nivet, unpublished data).
Although these studies clearly indicate global climate was
a forcing factor for Asian aridification, the precise linking
mechanism remains to be determined. As previously proposed by Dupont-Nivet et al. (2007), one of the links may
be provided by global sea-level lowering forcing the
retreat of the sea from Central Asia. However, poor age
constraint on the sea retreat has yet precluded definitive
confirmation of the role of the proto-Paratethys Sea as a
moisture source for the Asian continental interior.
To better constrain the age of the sea retreat, we studied
the Paleogene sedimentary records of the easternmost
extent of this sea close to the palaeodepocenter of the
southwest Tarim Basin along the West Kunlun Shan
7 0 °E
k
Eqa
G uator 60°
Islamabad
90°
3 8°N
Ce
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Darvaz fault
So
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Tibet
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Tarim Basin
3 5 °N
ar
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Ka
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AFRICA
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30°N
Yarkand
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30°
an
ASIA
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Maza Tagh
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lm
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fa
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Main
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80°E
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PaEUROPE
Herat fault
The Tarim Basin is part of a relatively undeformed crustal block within the Indo-Asia collision system (Yin &
Thru
Pamir
iss
Gh
SW
Afghan-Tajik
Basin
GEOLOGICAL SETTING
7 5 °E
ey
Alai vall
Tian Shan
100 km
(Fig. 1). Bosboom et al. (2011) recovered age-diagnostic
marker fossils from the last marine sediments indicative of
a late Lutetian–early Priabonian age range (ca. 42–36 Ma),
showing that the youngest major sea retreat from the palaeodepocenter predates both the Oligocene–Miocene regional uplift of the Pamir Mountains and Kunlun Shan as well
as the major eustatic sea-level falls associated with the
EOT (ca. 34 Ma) and the mid-Oligocene (ca. 30 Ma),
which were often considered as controlling mechanisms
underlying the sea retreat (Sobel & Dumitru, 1997;
Dupont-Nivet et al., 2007). To enhance understanding of
the mechanisms and palaeoenvironmental impacts of the
sea retreat from the southwest Tarim Basin, we aim to significantly improve the resolution of the previous age
framework by providing new bio- and magnetostratigraphic age constraints and by refining previous biostratigraphic
results of Bosboom et al. (2011). This improved integrated
stratigraphic framework of the last major marine to continental transition in the Tarim Basin will allow for a discussion on the interplay between Tibetan Plateau uplift,
global climate, palaeoenvironmental changes in the Asian
interior and the palaeogeographic changes that are associated with the proto-Paratethys Sea in the Tarim Basin.
Lha
sa t
erra
ne
Fig. 1. Locations of the lithostratigraphic sections (KZ, Kezi; AT, Aertashi; KY, Keliyang) are displayed on the schematic geological
map of the Pamir displaying major tectonic features (modified from Cowgill, 2010). The inset shows the locations of the Tarim and
Xining Basins on a large-scale map of Eurasia (present-day coastal outline obtained from GPlates 0.9.7.1).
622
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
Harrison, 2000). The sedimentary infill is primarily
composed of Paleozoic and Mesozoic clastic sediments,
which were folded by successive accretion of continental
terranes from the late Triassic until the Eocene Indo-Asia
collision at ca. 50 Ma (Tian et al., 1989; Hendrix et al.,
1992; Yin & Harrison, 2000; Robinson et al., 2003; Jia
et al., 2004; van Hinsbergen et al., 2012). Marginal tectonic overthrusting of the Tian Shan, the Pamir Mountains and the Kunlun Shan by the northward movement
of India towards Eurasia during the Cenozoic, probably
reactivated two major distal foreland basins, the Kuche
depression along the southern margin of the Tian Shan
and the southwest depression along the West Kunlun
Shan (Burtman & Molnar, 1993; Jia, 1997; Yin & Harrison, 2000; Yang & Liu, 2002; Cowgill, 2010). The latter
has its depocenter near Yarkand and is the focus of this
study (Fig. 1; Yang & Liu, 2002).
Marine deposition in the southwest depression supposedly initiated during Cenomanian times (Tang et al.,
1992; Burtman & Molnar, 1993; Burtman, 2000), though
marine fossil traces have been described from older sediments of Barremian to Albian age (Guo, 1991; Lan &
Wei, 1995). The sea entered the Tarim Basin from neighbouring basins in the west through the present-day Alai
Valley. Its deposits are typical of a shallow, proximal marine environment and yield distinct fossil assemblages of
bivalves, ostracods, dinoflagellate cysts and calcareous
nannofossils that allow inter- and intra-basin stratigraphic
correlations (e.g. Mao & Norris, 1988; Tang et al., 1989;
Lan & Wei, 1995; Yang et al., 1995; Bosboom et al.,
2011). Strong similarities between the fossil assemblages
from the Tarim Basin with Central Asia and Europe show
that the sea interconnected various Eurasian basins and
belonged to the Tethyan Realm (Mao & Norris, 1988;
Dercourt, 1993; R€ogl, 1999; Popov et al., 2004; Bosboom
et al., 2011). A total of five major marine incursions into
the Tarim Basin have been recognized from the Late Cretaceous–Paleogene sedimentary record, of which the third
is considered as the largest as it extended into the central
Maza Tagh range and the northern Kuche Depression
(Figs 1 and 2; Tang et al., 1989; Lan & Wei, 1995; Burtman et al., 1996; Burtman, 2000). The focus of this study
is on the fourth transgression representing the last major
incursion, as the fifth transgression has only been recognized along the westernmost margin of the basin, west of
Kashgar (Fig. 1; Lan & Wei, 1995; Lan, 1997). After this
fifth transgression, the connection of the Tarim Basin to
the retreating sea remains elusive. Brackish-marine conditions may have occasionally reoccurred through the Oligocene and Miocene as indicated by foram and ostracod
findings and negative oxygen isotope shifts (Zheng et al.,
1999; Gao et al., 2000; Jia et al., 2004; Graham et al.,
2005; Ritts et al., 2008; Kent-Corson et al., 2009),
but this younger re-entrance of the Paratethys Sea in the
Tarim Basin remains to be confirmed and continental
deposition was prevalent.
Thrusting and exhumation of the Pamir and West Kunlun Shan may have initiated as early as middle Eocene and
clearly intensified in the early Miocene according to various data from sedimentology (Burtman, 2000; Yin et al.,
2002), stable isotope and provenance (Bershaw et al.,
2012), thermochronology (Sobel & Dumitru, 1997; Amidon & Hynek, 2010), palaeomagnetism (Thomas et al.,
1994; Yin et al., 2002) and backstripping analyses (Yang &
Liu, 2002). However, rapid uplift and topographic expression of the Pamir–Kunlun system is prominently indicated for Oligocene–early Miocene times, evidence for an
earlier uplift is sparse and not well constrained (Yin et al.,
2002; Cowgill, 2010). The southwest Tarim Basin consequently developed into a proximal foreland depression experiencing rapid accumulation of coarse-grained
clastics. These sediments have been weakly deformed by
basinward thrusting and overloading of the Kunlun Shan,
which is ongoing until today in response to the continuous
northward movement of India into Eurasia.
LITHOSTRATIGRAPHY OF SAMPLED
SECTIONS
In this study, we apply the nomenclature used in Bosboom et al. (2011); Fig. 2). The marine sequence of
Paleogene age is referred to as the Kashi Group, which
comprises in chronological order the Aertashi, Qimugen,
Kalatar, Wulagen and Bashibulake Formations. The overlying continental Wuqia Group consists of the Kezilouyi,
Anjuan and Pakabulake Formations. Here, we focus on
the fourth marine incursion associated with the marine
Kalatar and Wulagen Formations, which are found across
the entire southwest depression of the Tarim Basin (Bosboom et al., 2011).
To improve the chronological stratigraphic framework
of the sea retreat we provide new magnetostratigraphic
age control on the Aertashi (37°58′N, 76°33′E) and Kezi
(38°26′N, 76°24′E) sections to aid previous biostratigraphic assessments (Fig. 3a, b; Bosboom et al., 2011).
Moreover, new samples for biostratigraphic analysis were
collected from the Wulagen, Kalatar and Upper Qimugen
Formations at Kezi and Aertashi. In addition, the new
Keliyang section (37°27′N, 77°86′E) in the east of the
southwest depression (Figs 1 and 3c), that has been earlier described by Jin et al. (2003), has been sampled as
well for biostratigraphic analyses.
The lithostratigraphic correlations between the three
studied sections are based upon previous lithostratigraphic descriptions (Mao & Norris, 1988; Tang et al., 1989;
Dequan et al., 1996; Jia et al., 2004; Yang et al., 2012)
and our earlier study of the Kezi and Aertashi sections
(Figs 4 and 8; Bosboom et al., 2011). The stratigraphic
thicknesses of the recognized lithostratigraphic units were
measured to decimetric precision. The sections are
aligned at the zero metre level that is defined by the last
shell bed. A detailed lithostratigraphic description of the
studied sections and a preliminary interpretation of the
depositional environment of the analysed sections are
given in Table 1.
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
623
R. Bosboom et al.
20
25
30
35
40
AGE (Ma)
45
50
55
60
Middle Late Early Late Early M L
Miocene
Eocene
Oligocene
15
FORMATION THICKNESS
E M L Early
Paleocene
10
Pakabulake
350 – 2200 m
Anjuan
70 – 1000 m
Kezilouyi
200 – 500 m
Bashibulake
(5 members)
0 – 380 m
LITHOLOGY
Brownish-red to grayish-white mudstones and siltstones
Brownish-red mudstones interbedded with grayish-green mudstones,
siltstones and sandstones
?
Red-beds including mudstones, siltstones, sandstones and gypsum
interbeds
Brownish-red mudstones with interbeds of siltstones, laminated gypsum
and grayish-green sandy shell beds
Fine-grained cross-bedded sandstones in 5th member
Wulagen
10 – 200 m
Grayish-green mudstones intercalated with shell beds, shelly limestones
and muddy siltstones (occasionally overlain by massive gypsum beds)
Kalatar
20 – 180 m
Grey massive limestones, marls and grayish-green mudstones with
interbeds of shelly limestones, oolitic limestones, shell beds and gypsum
EOT
5?
4
Brownish-red (gypsiferous) mudstones intercalated with grayish-green
mudstones (occasionally overlain by brown gypsiferous mudstones and
massive gypsum beds)
Upper Qimugen
3?
10 – 150 m
Grayish green mudstones, siltstones and fine-grained sandstones intercalated
with shelly limestones
Lower Qimugen
Massive gypsum beds intercalated with gypsiferous mudstones and
dolomitic limestones
Aertashi
20 – 300 m
Tuyiluoke
0 – 60 m
Red (gypsiferous) mudstones intercalated with some gypsum beds (only
present along Tian Shan)
Yigeziya
0 – 130 m
Purplish-red and gray limestones intercalated with marls, dolomites and
gypsiferous mudstones
90
Wuyitake
10 – 120 m
95
Kukebai
70 – 210 m
65
SEA-LEVEL
70
80
85
Late
Cretaceous
75
Brownish-red gypsiferous mudstones intercalated with gypsum beds and
siltstones
Grayish-green and dark gray mudstones intercalated with marls and shelly
limestones at top
Brown mudstones intercalated with siltstones and fine-grained sandstones
at base
2?
1?
100
Fig. 2. Simplified regional lithostratigraphic framework of the marine incursions recognized in the southwest Tarim Basin based on a
review of existing Chinese literature. The lithostratigraphy and corresponding thicknesses are summarized from Jia et al. (2004), Mao
& Norris (1988) and Tang et al. (1989), whereas the preliminary age estimates are based upon calcareous nannofossils (Zhong, 1992),
bivalves (Lan & Wei, 1995), ostracods (Yang et al., 1995), dinoflagellate cysts (Mao & Norris, 1988) and benthic foraminifera (Hao &
Zeng, 1984). The shaded area highlights the Wulagen and Kalatar Formations corresponding to the fourth and last major sea retreat
from the basin palaeodepocenter, accurately dated by bio-magnetostratigraphy in this study. The approximate relative changes in sealevel of each transgression are shown by the thick-dotted line and are simply based upon the reported eastward extent of each incursion
into the basin. The thin-dotted line shows the Eocene–Oligocene Transition (EOT), which as shown by this study led to a long period
of nondeposition in the southwest Tarim Basin. Up into the Miocene minor brackish-marine incursions reoccurred (Zheng et al., 1999;
Gao et al., 2000; Jia et al., 2004; Graham et al., 2005; Ritts et al., 2008; Kent-Corson et al., 2009), but their timing and connection to
the Paratethys remain to be confirmed. Note that the synthetic log reflects the approximate induration of the regional lithostratigraphy
and that the thicknesses of the formations are not to scale. See Fig. 8 for explanatory legend of lithostratigraphic patterns used.
In summary, facies analyses indicate that the lithostratigraphy constitutes a shallowing-upward cycle (or cyclothem) typical for shallow epicontinental seas (Aigner
et al., 1990; Reading, 2006). The marine deposits are
ascribed to the Kalatar and Wulagen Formations of the
fourth marine incursion, of which the associated regression marks the permanent shift from a marine to continental depositional environment in this part of the Tarim
Basin. The gradual character of this shift observed in the
field indicates no evidence for the presence of a major
unconformity associated with the sea retreat. The frequent
alternation of siliciclastics and carbonates suggests that
superimposed on the overall shallowing-upward trend,
high-frequency fluctuations in relative sea-level, local
624
climate and sediment supply result in lowstand/wet siliciclastic shedding and highstand/dry carbonate build-up
(Budd & Harris, 1990; Reading, 2006). At Keliyang clastic
sediments, gypsum beds and oxidization are overall more
frequent, whereas fosilliferous carbonate beds are less
numerous, indicating shallower, more restricted depositional conditions. Nonetheless, the overall similarity
between the sections in terms of lithostratigraphy shows
that the fourth shallowing-upward cycle occurred basinwide (Fig. 8). At Aertashi, our stratigraphic coverage
extends upward into the siliciclastic continental deposits
of the Wuqia Group, typical of delta to alluvial plain settings
(Yin et al., 2002). An abrupt lithologic change is expressed
near the 740 m level by the disconformable transition from
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
(a)
ene
Eoc
dis
con
form
ity
Olig
oce
ne
(b)
Kezilouyi
Kalatar
Qimugen
(d)
ashi
Aert
n
uge
tar
Qim
Kala
ilouy
gen
Kez
Wula
(c)
i
(e)
(f)
Fig. 3. Field photographs of formations and sedimentological features. (a) Significant change in lithology at the Eocene–Oligocene
boundary in the Aertashi section. (b) Overview of the Qimugen, Kalatar and Kezilouyi Formations at the Aertashi section. The Wulagen Formation is not visible. (c) Overview of the Paleogene formations at the Keliyang section. (d) Dense oyster shell accumulation in
sandy packstone matrix of the Kalatar Formation at the Aertashi section. (e) Strongly bioturbated calcareous-rich mudstone bed at the
marine-continental transition in the Aertashi section. f. Cross-bedded red sandstone of the continental Wuqia Group at the Aertashi
section.
floodplain mudstones to a more dynamic depositional
environment with dominantly massive decameter-scale
cross-bedded sandstone channel beds (Fig. 4).
but our qualitative analyses provide reliable biostratigraphic constraints.
Ostracods
BIOSTRATIGRAPHY
The samples for foraminifer, ostracod, bivalve, calcareous
nannofossil and organic-walled dinoflagellate cyst (dinocyst) analyses were collected from representative marine
beds throughout the Kalatar and Wulagen Formations of
the three sections (Fig. 8). The previously studied Kezi
section (Bosboom et al., 2011) was extended downward
for biostratigraphic sampling. Age correlations are based
upon the standard macro- and microfossil zonations of
the geologic time scale by Gradstein et al. (2012). Preservation and abundance of the newly collected samples are
generally not sufficient to perform quantitative analyses,
The preparation followed standardized techniques. Samples from Keliyang were almost barren, but the few preserved specimens are indicative of an Eocene age. Newly
collected samples from Aertashi are generally very poor in
ostracods. Ostracods are badly preserved as most of the
ornamentation has been dissolved, making precise discrimination at species level very difficult and therefore
only few specimens have been recognized. The main taxa
are represented by small-sized specimens of Cytheridea
ex. gr. perforata perforata (Roemer) and Monsmirabilia
triebeli (Keij). They are associated with rare individuals of
Cyterella compressa (Von M€
unster), Eucytheropteron plicatoreticulatum Margerie, Rugierria semireticulata Haskins,
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
625
R. Bosboom et al.
Kezi section
GTS2012
(b) Mass susceptibility (10E-6 m3 kg–1) (c) VGP latitude (°)
Gradstein et al. (2012)
(d) Polarity
200
200
200
200
100
100
100
100
0
0
0
0
Remagnetized
–100
–200
–200
–100
0
0.4
0.8
–100
–200
–90S
1.2
0
90N
Chrons
–200
C8
Aertashi section
(a) Lithostratigraphy
(b) Mass susceptibility (10E-6 m3 kg–1) (c) VGP latitude (°)
(d) Polarity
1600
1600
1600
1600
1500
1500
1500
1500
1400
1400
1400
1400
1300
1300
1300
1300
28
N12
C10
R12
1100
1200
1100
1200
1100
1100
27
N11
R11
N10
C11
N9
29
30
Rupelian
1200
26
C9
R10
1200
Age (Ma)
Chattian
e
ton
es arse
Limry co
Ve diume
Mery fin
Vet
Siul d
M
–100
Oligocene
Wuqia Group
Wulagen Fm
Stratigraphic level (m)
(a) Lithostratigraphy
31
N8
R8
C12
32
N7
1000
1000
1000
1000
900
900
900
900
33
R7
EOT
800
800
800
800
700
700
700
700
35
N6
R6
? C15
N5
600
600
600
600
C16
N4
500
500
500
34
C13
Priabonian
Stratigraphic level (m)
?
36
37
500
R4
400
400
N3
300
300
300
300
N2
C17
Wuqia group
N1
200
200
100
200
100
200
100
100
?
C18
38
Eocene
400
Bartonian
400
39
40
R1
41
0
0
C19
Remagnetized
–100
–100
–200
–200
–100
–100
C20
e
ton
es arse
Limry co
Ve diume
Mery fin
Veilt
S d
Mu
626
0
–200
0
0.4
0.8
1.2
1.6
Lutetian
Wulagen Fm
0
?
42
43
–200
–90S
0
90N
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
Fig. 4. Lithostratigraphy (a), susceptibility (b), VGP latitude (c) and the corresponding magnetic polarity zones (d) correlated with
the geological time scale (GTS2012; Gradstein et al., 2012) for the Aertashi and Kezi sections. Zero level is defined by the last greencoloured shell bed. Positive VGP latitudes reflect normal polarity and negative latitudes reflect reversed polarity, indicated, respectively, by black and white polarity chrons. Polarity zones shaded in grey have indeterminable polarity. VGP latitudes rejected by 45°
cut-off and isolated VGP latitudes in an interval of opposing polarity are both neglected and indicated with open white symbols. The
preferred correlation with the time scale is dark-shaded, whereas the rejected correlation is light-shaded. See Fig. 8 for explanatory
legend of lithostratigraphic patterns and symbols used.
Table 1. Lithologic description and interpretation of the depositional environment of analysed stratigraphic sections correlated with
the existing chronostratigraphic framework of the southwest Tarim Basin.
Chronostratigraphic
correlation
Stratigraphic level
Lithostratigraphic description and deposition environment interpretation
Aertashi: 20 m level to top
Kezi: 15 m level to top
Keliyang: 15 m level to top
The green siltstones and sandstones from the underlying Wulagen
Formation are gradually replaced by the red continental deposits of the
Wuqia Group, characterized by laminated mudstones interbedded by
siltstones and fine sandstones with planar cross laminations (Fig. 3f).
Upwards the grain-size increases, fine to medium slightly incised
metre-scale channel sandstone beds become more common, whereas red
mudstone beds become less frequent. A significant change in lithology
occurring at 737 m level is expressed by the abrupt disappearance of
floodplain mudstone deposits and appearance of massive decameter-scale
cross-bedded middle red sandstone channel beds, which remain
dominant until 1200 m level (Figs 3a and 4). The contact itself is
characterized by the presence of gypsum nodules. Occasionally levels
characterized by red (gypsiferous) mudstones (with mudcracks), red
muddy gypsum beds and green fine sandstone beds are present
The general continental sequence is interpreted as representing
dominantly alluvial floodplain deposits with occasional (brackish)
lacustrine intervals and correlates to the Wuqia Group. Few measured
palaeocurrent directions point to a predominant northward flow
direction (Fig. 4)
Wuqia group
Aertashi: 105 to 20 m level
Kezi: 70 to 15 m level
Keliyang: 75 to 15 m level
The lower part of the unit is similar to the underlying Kalatar Formation
and comprises green mudstones interbedded with greyish-green coloured
siltstones, fine sandstones and shelly limestones rich in oysters, other
bivalves, miliolids and echinoids. Red (laminated) mudstones intercalated
with thin shell beds constitute the upper part. Upward the shell beds are
gradually substituted by irregularly bedded green calcareous
(bioturbated) siltstones and fine sandstones (Fig. 3e)
At Aertashi and Kezi these deposits have previously been interpreted as
sub- to intertidal mudflat deposits and have been correlated with the
Wulagen Formation based upon the characteristic fossil assemblages
(Bosboom et al., 2011)
Wulagen Fm
Aertashi: 195 to 105 m level
Kezi: 130 to 70 m level
Keliyang: 130 to 75 m level
This unit is a distinct resistant interval of massive fine to middle green
(bioturbated) sandstones and grey (oolithic) grainstones interbedded by
green mudstones. It is exceptionally rich in bivalves, but also contains
traces of bryozoa
These characteristics are typical of intertidal sandy shoals, carbonate
ramps and mudflats (Fig. 3d)
Kalatar Fm
Aertashi: base to 195 m level
Kezi: base to 130 m level
Keliyang: base to 130 m level
Red (gypsiferous) mudstones and interbeds of red- and green-coloured
laminated (muddy) gypsum constitute the basal unit
These deposits are interpreted as supratidal (salt) mudflat deposits,
recording the regression phase of the third incursion into the Tarim
Basin
Upper Qimugen Fm
Cytheretta vulgaris Ducasse and Hermanites trigemmus
Tambareau. This studied ostracod assemblage suggests
correlation with the Wulagen Formation (Dequan et al.,
1996), which is in excellent agreement with the previous
correlation of corresponding stratigraphic levels at Kezi
(Bosboom et al., 2011). The stratigraphic range of the
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
627
R. Bosboom et al.
identified species is somewhat larger, but most of them
were encountered in high numbers in European basin
sediments of middle to late Eocene age (e.g. Keij, 1957;
Pietrzeniuk, 1969; Szczechura, 1977; Keen, 1978; Ducasse et al., 1985; Lord et al., 2009; Yesßilyurt et al., 2009;
Pirkenseer & Berger, 2011).
Bivalves
As all aragonite mollusk representatives were secondarily
leached, this study focuses on oysters (Ostreidae), a group
of epifaunal pteriomorph bivalves producing calcite shells
(Stenzel, 1971). Taxonomic identification largely follows
Lan & Wei (1995), representing the most recent revision
of regional systematic literature (Table S1).
Consistent with previous results (Bosboom et al.,
2011), the samples collected from both the Aertashi and
Kezi sections include representatives of Sokolowia,
Kokanostrea and Flemingostrea. Keliyang samples solely
included Sokolowia bushii specimens. This SokolowiaKokonostrea assemblage confirms the previous correlation
with the Wulagen Formation (Lan & Wei, 1995; Lan,
1997). The Sokolowia bushii species were widely distributed in the proto-Paratethys and have been recognized in
the Ferghana Basin (Vyalov, 1937), Alay Valley (B€ohm,
1903), Syr Darya Basin (Gorizdro, 1913) and AfghanTajik Basin (Desio & Martina, 1975) of Central Asia and
in the Transylvanian Basin of Romania (Rusu et al.,
2004), pointing to well-established connections throughout Eurasia and a late Lutetian to early Bartonian age.
Calcareous nannofossils
The samples from Aertashi (10), Kezi (16) and Keliyang
(111) sections have been prepared following standardized
techniques (Bown & Young, 1998) and analysed with a
light microscope at 12009 magnification along two transverses of the slide and sometimes extended at 4009 due
to the paucity of the specimens in most of the samples.
The biostratigraphic attribution is primarily based on the
standard zonations (Okada & Bukry, 1980; Table S2 and
Fig. S1; Gradstein et al., 2012).
In general nannofossil abundance and preservation in
the newly collected samples are very limited. The calcareous nannofossil distribution in samples from the Aertashi
section is in good agreement to earlier findings from corresponding stratigraphic levels at Kezi (Bosboom et al.,
2011). The presence of few Reticulofenestra umbilicus and
Ericsonia formosa throughout the upper part of the section
matches the NP 16 and NP 17 Zones (Martini, 1971)
recorded in the Wulagen Formation by Zhong (1992).
Hence, our interpretation confirms the previous correlation with the Wulagen Formation and allows a preliminary assignment to Zone CP14 of late Lutetian to earliest
Priabonian age. The poor assemblage does not, however,
exclude a younger age. The new samples collected in the
lower part of the Kezi section and the lowermost sample
of the Aertashi section lack R. umbilicus, which could
628
indicate that the lower part of the sections corresponding
to the Kalatar Formation correlates to the older Zone
CP13, though we cannot exclude that its absence is
related to very poor preservation. In support to this older
Zone CP13 attribution for the Kalatar Formation, few
Lanternithus arcanus (NP15c; Bown, 2005) have been recognized in the Kezi section.
Almost all samples collected at Keliyang are barren in
nannofossils, however, one sample at the base of the
Wulagen Formation, contains Neococcolithes dubius. The
genus Neococcolithes is distributed from early Eocene to
the middle Eocene, therefore, at least this level is older
than the base of Zone CP15 (Varol, 1998; Sheldon, 2002),
confirming the previously assigned age.
Palynology
Sample preparation was performed following standardized palynological techniques, as described in Houben
et al. (2011). Taxonomy follows that cited in Fensome &
Williams (2004); Table S3 and Fig. S2).
In addition to the study of Bosboom et al. (2011), new
samples were collected at the Aertashi and Keliyang sections. Despite the general poor preservation and abundance, a few samples yield well-preserved age-diagnostic
dinoflagellate cysts. The presence of stratigraphically
important species as Rhombodinium draco and Melitasphaeridium pseudorecurvatum and the absence of Cordosphaeridium funiculatum suggest correspondence of the studied
interval to the Turbiosphaera filosofa Zone of Mao & Norris (1988) that belongs to the Wulagen Formation. Correspondence to this dinoflagellate zone confirms our
lithostratigraphic correlation with the studied interval at
the Kezi section (Bosboom et al., 2011), so our three sections all record the same fourth marine incursion. Resemblance of the Turbiosphaera filosofa Zone to the Mps
Interval Zone of central Italy (Brinkhuis & Biffi, 1993;
Brinkhuis, 1994; Mourik & Brinkhuis, 2005), led to a preliminary early Priabonian age assignment for the Wulagen
Formation (Bosboom et al., 2011), which was primarily
based on the overlapping presence of C. funiculatum and
the rare presence of M. pseudorecurvatum. However, the
base of this Mps Interval Zone is poorly defined due to a
palynologically barren interval at the lower part of the
central Italian sections (Brinkhuis & Biffi, 1993) and thus
hampered a better age constraint. A new magnetostratigraphically calibrated dinoflagellate cyst stratigraphy
from a borehole in the Omsk region in southwestern Siberia (Iakovleva & Heilmann-Clausen, 2010) allows for a
refinement of the previous age assignment of the fourth
regression. In Siberia, C. funiculatum is already present in
the Ypresian (chron C22r) and occurred consistently from
late Bartonian (chron C17n) onwards, whereas M. pseudorecurvatum is already encountered within chron C23r.
Hence, the presence of these species is not necessarily
implying a correlation with the Mps interval. Although
the magnetostratigraphic correlation with the geologic
time-scale presented in Iakovleva & Heilmann-Clausen
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
(2010) is not unambiguous, based upon the presence of
Areosphaeridium diktyoplokum (≤C23n), Rhombodinium
draco (≤C19n) and Melitasphaeridium pseudorecurvatum
(≥C17r) and the absence of Lentinia serrata (≤C17r), Heteraulacacysta porosa (≤C17r) and Thalassiphora reticulata
(≤C15n), we constrain the age of the studied interval at
Kezi, Keliyang and Aertashi between latest Lutetian to
Bartonian (C19n to C17r). This is older than the previous
Priabonian age assignment (Bosboom et al., 2011), but
corroborates the correlation with calcareous nannofossil
Zone CP14.
fddijk’ of the Faculty of Geosciences at the Utrecht University.
Rock magnetism
To determine the rock-magnetic properties and carriers
of the collected samples and to devise the best procedure
for subsequent thermal demagnetization, rock-magnetic
analyses were performed first. Susceptibility at room temperature was measured on a KLY-2 susceptibility bridge
for each specimen (Fig. 4). Representative specimens of
characteristic lithologies were powdered and analysed for
their thermomagnetic behaviour using a Curie balance
(Mullender et al., 1993). These rock-magnetic analyses
show that in general two clearly distinct behavioural types
can be distinguished (Fig. 5).
Marine deposits (comprising greyish-green clastic and
carbonate rocks) generally show very weak irreversible
magnetic behaviour (magnetic moment in the order of 1–
10 mA m 2 kg 1) with a peak in magnetization around
500 °C interpreted as the oxidation of iron-sulphides into
magnetite (Passier et al., 2001). Reduction in magnetization occurs at temperatures close to the Curie temperature
MAGNETOSTRATIGRAPHY
Paleomagnetic sampling at the Kezi and Aertashi sections
was performed using a standard portable electric drill
powered by a portable gasoline generator. Samples were
collected at a resolution ranging from 0.4 to 6.0 m and
orientated with a magnetic compass. After the fieldwork
samples were cut into core specimens of approximately
2 cm in length and palaeomagnetic analyses were carried
out in the shielded Paleomagnetic Laboratory ‘Fort Hoo1.Marine
0.03
0.02
0.01
0
200
100
300
400
500
600
700
0.01
0.01
0.00
100
200
300
400
500
600
Temperature (°C)
AT368 (–70.0 m) green sand
KZ082 (–9.8 m) red mud
–1
0.01
0.00
0
700
100
200
300
400
500
600
700
0
100
Temperature (°C)
up/W
600
700
N
C
HT
500
600
C
HT
635
600
150 100
500
690
N
550
400
AT502 (483.4 m) red sand
C
up/W
300
up/W
100
350
200
Temperature (°C)
AT270 (187.7 m) red mud
up/W
N
Weight: 0.0762 g
T = 660°C
0.00
0
Temperature (°C)
Field: 150 – 300 m T
T = 650°C
–1
0.02
675
600
C
LT
100
150
600
AT368 (–70.0 m) green sand
KZ082 (–9.8 m) red mud
1.0
0.8
0.8
0.8
0.6
0.4
0.2
0.0
0.0
0.0
100
200
300
400
Temperature (°C)
500
600
700
0
100
200
300
400
Temperature (°C)
500
600
700
1.0
0.8
0.4
0.2
0
AT502 (483.4 m) red sand
AT270 (187.7 m) red mud
0.6
0.2
TC
Intensity
0.4
Intensity
1.0
0.6
TC
675
1.0
Intensity
Intensity
N
TC
TC
(c) Decay
AT502 (483.4 m) red sand
Weight: 0.0570 g
LT
(b) Thermal demagnetization
0.00
Field: 150 – 300 m T
Total Magn. (Am2 kg )
0.03
0.02
T = 575°C T = 660°C
Total Magn. (Am2 kg )
T = 575°C
Weight: 0.0713 g
–1
T = 300°C
0.04
Total Magn. (Am2 kg )
–1
Total Magn. (Am2 kg )
(a) Curie balance
Field: 150 – 300 mT
Weight: 0.0726 g
0.05
4. Continental coarse
AT339 (312.8 m) red mud
AT023 (14.2 m) red mud
KZ103 (–75.1 m) green mud
Field: 150 – 300 mT
3. Continental fine
2.Transition
0.6
0.4
0.2
0.0
0
100
200
300
400
Temperature (°C)
500
600
700
0
100
200
300
400
500
600
700
Temperature (°C)
Fig. 5. Plots showing typical rock-magnetic behaviour of representative specimens of greyish-green coloured marine beds (1), red
coloured mudstones of the marine-continental transition (2) and red continental mudstones (3) and sandstones (4) from the Kezi (KZ)
and Aertashi (AT) sections. (a) Temperature dependence of the magnetic moment upon Curie balance processing. (b) Orthogonal
plots showing the thermal demagnetization trajectories in tilt-corrected (TC) coordinates. Solid circles represent projections in the
vertical plane and open circles represent projections in the horizontal plane. For red continental beds both a low-temperature component (LTC) and a high-temperature component (HTC) are distinguished. (c) Decay of intensity upon thermal demagnetization. Solid
lines represent absolute decay paths and dotted lines represent the standard deviation of the decay path.
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
629
R. Bosboom et al.
of magnetite (~580 °C) and occasionally at lower temperatures, suggesting magnetite and iron-sulphides are the
dominant magnetic carriers. On the other hand, the continental red-coloured clastics of continental origin generally
express stronger and reversible thermomagnetic behaviour (magnetic moment in the order of 10–100 mA
m 2 kg 1) and show a clear decrease in magnetization
near the Curie temperature of magnetite (~580 °C) and
more frequently of hematite (~680 °C).
Thermal demagnetization
Single specimens were thermally demagnetized in a
shielded oven by using up to 22 temperature steps varying
between 5 and 100 °C. The remanent magnetization at
each temperature step was measured by a 2G Enterprises
DC SQUID cryogenic magnetometer. After progressive
removal of an overprint component at temperatures of
100–300 °C, the trajectories of the characteristic remanent magnetization (ChRM) show linear decay towards
the origin at temperatures which are in agreement with
the previous rock-magnetic results (Fig. 5). The ChRM
directions of the marine facies decay in the direction of
the origin between 100 and 450 °C, further indicating
iron sulphides as the dominant magnetic carriers. Above
temperatures of 500 °C, the magnetic intensity strongly
increases, likely resulting from the aforementioned formation of magnetite by oxidization of iron sulfides. From the
ChRM trajectories of the continental facies, two components can be distinguished which both decay towards the
origin (Fig. 5). In general, the low-temperature component (LTC) is removed from 350 to 600 °C, whereas the
high-temperature (HTC) unblocks from 640 to 700 °C,
supporting magnetite and hematite as the dominant ferromagnetic carriers.
ChRM analyses
The ChRM directions were calculated from orthogonal
plots by application of principal component analysis
(Kirschvink, 1980). The line-fits were performed on a
minimum of four temperature steps and were forced
through the origin only in a few cases where directions
clustered in a distinct normal or reversed position. Maximum angular deviations (MAD) on the line-fits were usually below 15°, but MAD of up to 30° were accepted if the
polarity could be clearly discerned. Great circle ChRM
analysis (McFadden & McElhinny, 1988) was performed
for a number of samples without linear decay, but clear
demagnetization path along a great circle. Virtual geomagnetic pole (VGP) latitudes were calculated from the
obtained ChRM directions. Outliers and transitional
directions lying over 45° from the mean were systematically and iteratively discarded (Deenen et al., 2011;
Tables S4 and S5). The remaining directions separate in
two antipodal clusters (after bedding tilt correction) from
which the mean normal and reversed ChRM directions
were calculated (Fisher, 1953).
630
To assess the nature of the acquired ChRM directions,
the reversals test of McFadden & McElhinny (1990) was
applied to the Kezi and Aertashi datasets, separately for
the marine and continental facies. The reversals test is
indeterminate for the marine sediments as the majority of
ChRM directions of this behavioural type is of normal
polarity. The in situ mean normal directions plot very
close to the approximate present-day field in the field area
(Fig. 6; declination of 3.2° and inclination of 57.6°). In
addition, at both sections the shift in rock-magnetic
behaviour ( 3.7 to 14.0 m level at Kezi; 15.4 to 12.0 m
level at Aertashi) is conspicuously close to a polarity
reversal ( 4.7 to 11.5 m level at Kezi; 19.1 to 8.5 m
level at Aertashi). This overlap between the change in ferromagnetic composition and polarity shows that the
majority of the iron sulfides in the marine sediments have
probably been remagnetized in present-day field and that
their ChRM directions are unreliable for correlation with
the geological time scale. As the continental red-beds of
the Kezi section have solely yielded reversed ChRM
directions, a reversal test cannot be applied. For the
Aertashi section, however, the continental facies dataset
passes the reversals test with classification A (Fig. 6), confirming the primary origin of the magnetization.
Correlation with the geologic time scale
Based on the verified primary origin of the magnetization
of the continental samples, the pattern of polarity zones
recognized at Aertashi may be correlated with the geologic
time scale 2012 (GTS2012) of Gradstein et al. (2012). The
polarity zones are based on at least two consecutive VGP
latitudes of identical polarity such that isolated directions
within an interval of opposing polarity are neglected
(Fig. 4). Polarity zones were numbered N1 to N12 from
bottom to top for the Aertashi section. From the resulting
correlations to the GTS2012 presented below, corresponding accumulation rates were calculated (Fig. 7).
The initial correlation is guided by the independent
biostratigraphic constraints (this study and Bosboom
et al., 2011) obtained from the Kezi and Aertashi sections.
Based on the identified fossil assemblages, the age of the
youngest marine sediments is defined by correlation with
calcareous nannofossil Zone CP14. Given these age constraints, the basal continental red beds must be younger
than the base of magnetochron C19r (Fig. 8). From the
acquired pattern of polarity zones, the two long reversed
intervals (R1 and R7), separated by a dominantly normal
polarity interval (N1-N6), are most striking. However,
this polarity pattern does not easily correlate to the
GTS2012 above chron C19r, which suggests there is a
hiatus present in the Aertashi section. Based upon our
field observations, this hiatus would likely be positioned
at the basal contact of the massive erosive sandstone beds
at the 737 m level marked by gypsum nodules and coinciding with a minimum in bulk magnetic susceptibility
(Figs 3a and 4; Table 1). The polarity pattern of the part
below this hiatus is from bottom to top (neglecting the
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
IS
TC
AT green (TC after 45° cut-off)
N: D = 25.2°; I = 16.5°; α95 = 10.0°; n = 22 (24)
R: D = 199.9°; I = –29.4°; α95 = 24.7°; n = 6 (7)
IS
TC
AT red (TC after 45° cut-off)
N: D = 28.0°; I = 26.3°; α95 = 2.7°; n = 258 (298)
R: D = 204.0°; I = –28.4°; α95 = 3.2°; n = 211 (260)
IS
TC
KZ green (TC after 45° cut-off)
N: D = 3.4°; I = 34.8°; α95 = 4.8°; n = 74 (82)
R: D = 213.3°; I = –39.7°; α95 = 32.9°; n = 5 (7)
IS
TC
KZ red (TC after 45° cut-off)
R: D = 203.3°; I = –34.3°; α95 = 5.7°; n = 58 (70)
Fig. 6. Equal-area plots of the ChRM directions at the Kezi and Aertashi sections, shown separately for in situ (IS) vs. tilt-corrected
(TC) coordinates and green marine vs. red continental rock-magnetic behaviour. The plots show the least square fits and their Fisher
means for normal (N) and reversed (R) polarities. ChRM directions which have been rejected by 45° cut-off are shown in red and are
excluded from further analyses. Downward directions are shown as solid symbols, whereas upward directions are shown as open symbols. The circles indicate the alpha95 confidence limit of the Fisher mean directions. The direction of the present-day normal field is
indicated by the red square for comparison.
unreliable and remagnetized marine part of the magnetostratigraphy) characterized by a long reversed interval
(R1), followed by two broad dominantly normal polarity
zones (N1-N3 and N4-N5 including very short reversed
intervals), which are separated by a short reversed polarity
zone (R9). Above these long normal zones, a relatively
short reversed interval (R6) and a comparable normal
interval (N6) extend all the way up to the hiatus at the
737 m level. Taking the independent age constraints into
account, two alternative correlations (Fig. 4) to the
GTS2012 can be proposed for this lower part. The two
long dominantly normal polarity zones (N1-N3 and N4N5) may either correlate to chrons C18-C17 or C17-C16,
implying N6 correlates to either the base of C16n or
C15n. Correlation with chrons C17-C16 apparently provides adequate records of several short chrons within C17
and C18. However, it is found less likely because the long
reversed zone below (R1) would have to be correlated
with the short chron C17r, implying either unrealistic
variations in accumulation rate or the absence of chron
C18n, although no obvious unconformities have been
recognized in the field at the corresponding stratigraphic
levels. The preferred correlation of the two dominantly
normal zones (N1-N3 and N4-N5) is therefore to chrons
C18-C17. The upper part above the hiatus shows a conspicuous pattern of polarity zones (N7 to N12) which is
easily and unambiguously correlated with chrons C12 to
C9. This correlation yields nearly congruent sediment
accumulation rates varying between 5.6 and 23.2 cm
kyr 1 (Fig. 7), in good agreement with an earlier reported
rate of 10 cm kyr 1 (Yin et al., 2002). Note that both the
preferred correlation with chrons C18-C17 and the
rejected correlation with C17-C16 provide the same age
for the sea retreat and the disconformity.
DISCUSSION
Our results show that the fourth and last major incursion
into the Tarim Basin reached across most of the
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
631
R. Bosboom et al.
Aertashi
1600
14
.3
1500
17
.8
1400
13
.8
1300
14
.6
1200
9.
4
1100
Stratigraphic level (m)
1000
12
.9
900
5.6
300
16
.4
15
.1
400
11
.0
10
.3
500
12
11
.9
600
.9
20
700
14
.9
.0
800
2
200
23.
100
0
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
–100
Age (Ma)
GTS2012
Lutetian
C19
C18
Bartonian
C17
C16
C15
C20
Priabonian
Eocene
C13
C12
C11
C10
Rupelian
C9
C8
Chrons
Chattian
Oligocene
Fig. 7. Correlation of the polarity zones recognized in the Aertashi section to the GTS2012 (Gradstein et al., 2012) with corresponding accumulation rates in cm kyr 1. For the lower part, the rejected correlation is shown in light-grey. A hiatus of approximately
3.5 Myr is indicated by the correlation at the 737 m level.
southwest depression as the studied biomarkers allow
regional correlation of the Kalatar and Wulagen Formations (Fig. 1). Earlier biostratigraphic constraints proposed a late Lutetian–early Priabonian age range for this
marine incursion (Bosboom et al., 2011). Re-evaluation of
previous dinoflagellate cyst findings now suggests that the
youngest marine sediments of the studied sections were
deposited during an interval calibrated between base
C19n to top C17r (Fig. 8), which is in agreement with the
age constrained by bivalves (late Lutetian–early Bartonian), ostracods (middle to late Eocene), calcareous nannofossils (Zone CP14) and the earlier proposed age range.
However, the previous earliest Priabonian best age estimate (ca. 38 Ma; Bosboom et al., 2011; Gradstein et al.,
2012) is invalidated by our new magnetostratigraphic correlation with the GTS2012. Given the accumulation rates
and the length of polarity zone R1, the magnetostratigraphic correlation suggests the sea retreat occurred near
the base of C18r, i.e. close to the Lutetian–Bartonian
boundary at ca. 41 Ma (Gradstein et al., 2012), which
matches the calcareous nannofossil Zone CP14 age range
632
obtained by our biostratigraphic analyses of the youngest
marine sediments around zero metre level (Figs 8 and
10). From the regression upward, our magnetostratigraphic record of the Aertashi section extends up to chron
C9n and hence covers the middle Eocene (ca. 41 Ma) to
late Oligocene (ca. 27 Ma), i.e. from late Lutetian to early
Chattian times. Our correlation confirms the presence of a
hiatus at the base of the massive sandstone beds at the
737 m level (Figs 3a and 4). This major hiatus between
C16 and C12 has a duration of approximately 3.5 Myr
and includes the EOT. The improved age accuracy of the
Central Asian sea retreat in the late Eocene allows us to
discuss its palaeoenvironmental impact and controlling
mechanisms.
Paleoenvironmental impacts
Climate modelling studies (Ramstein et al., 1997; Zhang
et al., 2007) suggest that the sea retreat contributed to the
aridification of the Asian continental interior and intensification of the Asian monsoon system. Our results allow
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
200
Kezi Section
160
160
140
140
100
80
80
60
60
40
40
20
0
0
0
0
0
–140
–160
–160
–100
–120
–140
–40
–60
–60
–80
–80
–100
–100
–100
–120
–120
–120
–140
–140
–140
–160
–160
–160
–180
Red- or brown-colored
Mud-wackestone
Echinoids
Planar laminations
Green- or grey-colored
Packstone
Bryozoa
Cross-bedding
White- or yellow-colored
Grainstone
Gastropods
Herringbone cross-bedding
Coal
Sandy limestone
Miliolids
Trough cross-bedding
Mudstone
Conglomeratic limestone
Bioturbation
Current ripples
Siltstone
Dolomite
Ooids
Wave ripples
Sandstone
Gypsum
Organic debris
Flute casts
Conglomeratic siltstone
Teeth
Mottling
Channel
Conglomeratic sandstone
Shells
Mudcracks
Paleocurrent direction
Conglomerate
Bivalves
Rootlets
Internal deformation
Marl
Oysters
Caliche (nodular)
Upper Qimugen Fm
Legend
40
–160
–180
–200
–200
–220
–220
–240
–240
–260
–260
–280
–280
–300
–300
CP16
C17
b
C18
41
o
a
rac
FO
d
R.
R.
–120
–140
–80
–40
No data
–120
–60
–80
–20
Wulagen Fm
–100
–60
–20
Kalatar Fm
–100
–40
No data
–80
Kalatar Fm
–60
–80
Upper
Qimugen Fm
–60
Wulagen Fm
20
–40
C15
a
38
39
20
–20
C13
C16
CP14
120
100
20
–40
Mps
Eocene
120
20
–20
b
C19
42
43
44
c
CP13
60
a
Ssp
Bartonian
80
Dinoflagellates
Nannofossils
Bivalves
Ostracods
Water depth
100
40
–40
36
Biostratigraphy
120
40
–20
35
Lutetian
0
180
um
bil
icu
s
20
60
180
34
FO
40
80
200
b
37
Keziluoyi Fm
40
100
Keziluoyi Fm
60
–20
Upper
Qimugen Fm
Kalatar Fm
80
Dinoflagellates
Nannofossils
Bivalves
Ostracods
60
100
Water depth
80
Wulagen Fm
Stratigraphic level (m)
Keziluoyi Fm
100
Biostratigraphy
220
Chrons
Rac
Adi
Gse-Aal
-Cfu
C20
b
45
Mediterranean
Dinocyst
Zonation
Calcareous
Nannofossil
Zonation
Lithostratigraphy
120
Keliyang Section
240
CP15
220
Age (Ma)
Biostratigraphy
Dinoflagellates
Nannofossils
Bivalves
Ostracods
Water depth
240
Lithostratigraphy
GTS2012
Aertashi Section
Lithostratigraphy
Priabonian
Tarim Basin
Fig. 8. Litho-, magneto- and biostratigraphy of the analysed Keliyang, Kezi and Aertashi sections correlated with the GTS2012
(Gradstein et al., 2012). The sections are aligned along zero-level, which is defined by the last green-coloured shell bed. Measured
polarity zones and preliminary estimates of the palaeo-water depth are shown directly next to the lithostratigraphic columns. The thick
line shows magnetostratigraphic correlation of the Aertashi section with the GTS2012. The first occurrence (FO) of important agediagnostic biomarker species are indicated by dotted lines, but note that as the FO in our sections is dependent on sample resolution
and preservation, the lines only give an approximate age correlation. The actual age correlation based upon the encountered microfossil assemblages, is shown by shading the corresponding dinoflagellate cyst (light) and calcareous nannofossil (dark) zonations.
evaluating the validity of these models by comparing the
timing of the sea retreat from the Tarim Basin to coeval
Asian palaeoenvironmental records.
A study of palynomorphs and leaf fossils from northeast China shows an increase in seasonal precipitation
difference during the middle Eocene at C19r-C18r (ca.
41–40 Ma; Gradstein et al., 2012), which has been interpreted as intensification of the Asian monsoon system
(Quan et al., 2011, 2012). Although age control is limited
and the precipitation is based upon quantitative reconstructions, the timing of monsoon strengthening fits our
ca. 41 Ma age for the retreat. In the recently expanded
magnetostratigraphically dated sedimentologic and pollen
records in the Xining Basin along the northeastern
margin of the Tibetan Plateau (Fig. 9; R.E. Bosboom,
H.A. Abels, C. Hoorn, B.C.J. van den Berg, Z. Guo, &
G. Dupont-Nivet, unpublished data), an older more
gradual aridification step, corresponding to the regional
disappearance of a relatively wet perennial saline lake
system and prominent shift to relatively more arid flora,
initiates at the base of C18r (ca. 41.2 Ma), after a peak in
wet flora was reached at the base of C19n (ca. 41.4 Ma).
This aridification step closely corresponds to the re-evaluated ca. 41 Ma age of the sea retreat suggesting that the
timing of relatively wet palaeoenvironmental conditions
in the Xining Basin coincides with the fourth transgression in the Tarim Basin. The previous earliest Priabonian
best age estimate for the fourth sea retreat (ca. 38 Ma;
Bosboom et al., 2011) erroneously suggested a link with
the aridification step at ca. 37.1 Ma (top chron C17n.1n)
in the Xining Basin (Abels et al., 2011; Hoorn et al.,
2012). This minor aridification step has not been identified in the overlying continental record in the Aertashi
section (Fig. 9) and ongoing work will have to show if it
corresponds in age to the poorly dated last and fifth
regression limited to the westernmost margin of the basin
(Lan & Wei, 1995; Lan, 1997).
Furthermore, a major change to colder and dryer conditions at the EOT is well documented as a major regional
aridification step in the Xining record at the top of C13r
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
633
R. Bosboom et al.
Tarim Basin
Xining Basin
GTS2012
This study
Abels et al. (2012)
Bosboom et al. (submitted)
Gradstein et al. (2012)
Tarim Basin
Sea-level
Age (Ma)
C12
32
Age (Ma)Chrons
900
Disconformity
34
250
C13
800
C15
C16
36
200
Step 2
500
Priabonian
35
600
38
39
42
50
End lake system
Onset aridification
43
–100
Eocene
Low
–200
80
100
Steppe-desert
Angiosperms
Broad-leaved
Ferns
41
C19
Lutetian
4th regression
60
C18
C17
Bartonian
C19
41
Monsoon intensification MECO
Closure Turgay Strait
Incipient polar ice-sheets
Start cyclicity
40
40
4th incursion
0
40
100
100
39
C18
Step 1
Lutetian
200
Picea-event
C20
300
38
150
20
C17
37
Stratigraphic level (m)
Stratigraphic level (m)
Last gypsum bed
5th incursion?
700
0
Eocene
EOT
Antarctic glaciation
Asian aridification
Mongolian Remodelling
37
33
400
Priabonian
31
1000
Bartonian
Rupelian
1100
Oligocene
30
C11
1200
42
C20
0
20 40 60 80
Pollen sum (%)
100
High
0
Fig. 9. Magnetostratigraphic correlation between the sea retreat recorded in the southwest Tarim Basin (this study), the stepwise aridification recorded in the Xining Basin (Abels et al., 2011; R.E. Bosboom, H.A. Abels, C. Hoorn, B.C.J. van den Berg, Z. Guo, &
G. Dupont-Nivet, unpublished data) and the GTS2012 (Gradstein et al., 2012), clearly showing the synchronicity between
aridification, sea retreat and global climate in the Eocene. The relative sea-level curve of the Tarim Basin is an estimate and if the
poorly dated fifth regression is indeed associated with the EOT remains to be confirmed.
(33.9 Ma; Dupont-Nivet et al., 2007, 2008; Abels et al.,
2011; Gradstein et al., 2012; Hoorn et al., 2012). This
same change with associated biotic response is well
documented by several palaeoenvironmental studies in
the Asian continental interior (e.g. Meng et al., 1998;
Kraatz & Geisler, 2010; Gomes-Rodrigues et al., 2012).
The Asian aridification at the EOT corresponds in age
with the major hiatus found in the Aertashi section.
Long-term gradual cooling in the Eocene ultimately lead
to permanent Antarctic ice-sheet formation at the EOT
(Zachos et al., 2008). It is possible that the associated
major ~70 m eustatic sea-level drop (e.g. Pekar et al.,
2002; Miller et al., 2005; Katz et al., 2008; Lear et al.,
2008) resulted in a significant westward retreat of the
shallow epicontinental sea in Central Asia, although the
634
palaeogeogeographical distribution of the sea at that time
remains to be determined. This sea retreat coeval with aridification at the EOT corroborates the link between sea
retreat and aridification at ca. 41 Ma proposed above.
Acknowledging correlation is not causation, this linkage
supports climate models suggesting that the westward sea
retreat in Central Asia may have had a significant impact
on the moisture brought to the Asian interior and on the
development of monsoonal systems, in addition to the
established effects of Tibetan Plateau uplift and global climate cooling (Dupont-Nivet et al., 2007, 2008; Abels
et al., 2011; Hoorn et al., 2012). Sea retreat forced
by global sea-level lowering may thus provide one of
the mechanisms linking Asian aridification and global
climate.
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
30°
Middle Eocene
60°
90°
North
Sea
°N
60
Siberian
Sea
Scythian
ASIA
Turgai Strait?
Sea
ARIDIFICATION
Turan Sea
Me
di t
150°
120°
err
Tarim
Basin
Ferghana
Afghan-Tajik
Basins
4th retreat ~41 Ma
an
ea
nT
et h y
s
Xining Basin
°N
30
UPLIFT
AFRICA
Indian
Ocean
INDIA
tor
ua
Eq
Fig. 10. Preliminary palaeogeographic map displaying the fourth regression of the proto-Paratethys Sea from the Tarim Basin at ca.
41 Ma. Note that the coastlines are very approximate and based upon Dercourt (1993), Popov et al.(2004, 2010), Bosboom et al.
(2011) and findings of this study. The suggested changes in palaeogeography shown in the Turgai Strait and Siberian Sea are based on
Akhmetiev (2007), Akhmetiev & Beniamovski (2006) and Iakovleva & Heilmann-Clausen (2010) and an extrapolation of the results of
this study. Plate boundaries were obtained from GPlates 1.2.0 for 38 Ma. The retreat is time equivalent with significant aridification
steps reported from the Xining Basin (Abels et al., 2011; R.E. Bosboom, H.A. Abels, C. Hoorn, B.C.J. van den Berg, Z. Guo, &
G. Dupont-Nivet, unpublished data).
Controlling mechanisms
As mentioned previously, two main controlling mechanisms may be suspected for the retreat of the Tarim sea:
eustatic sea-level lowering associated with global climate
and/or tectonism associated with the Indo-Asia collision.
We interpret our results to suggest a combination of both
at different timescales. On the one hand, tectonic forcing
is consistent with the observed long-term westward
retreat from the Tarim Basin, from the maximum third
incursion in the early Eocene until the minor fifth incursion restricted to the westernmost margin in the late
Eocene. This corroborates with initial early Eocene IndoAsia collision deformation affecting the northern part of
the proto-Tibetan plateau (e.g. Jolivet et al., 2001; Clark
et al., 2010) and possibly the East and West Kunlun Shan
(Sobel & Dumitru, 1997; Yin et al., 2002; Graham et al.,
2005), thus providing a distal source to the south that may
have led to gradual infilling of the Tarim Basin. This is
supported by the relatively high accumulation rate of
dominantly fine-grained fluvial sandstones with approximately northward palaeoflow directions observed in the
siliciclastic parts of our sections and by the gradual continuous character of the marine-continental transition,
rather than a major unconformity that is expected in the
case of significant relative sea-level fall (Figs 4 and 7).
On the other hand, eustatism is more likely to explain
the shorter term variations expressed by the five successive sea incursions into the Tarim Basin. The regression
at ca. 41 Ma is concomitant with the closure of the WestSiberian Sea and Turgai Strait (Akhmetiev & Beniamovski,
2006; Akhmetiev, 2007; Iakovleva & Heilmann-Clausen,
2010), disconnecting the proto-Paratethys Sea from the
Arctic Sea (Fig. 10). Although the age is poorly constrained, simultaneous regression at such large geographical distance may support a causal link between regional
sea-level and the late Lutetian sea retreat from the Tarim
Basin. The age of the sea retreat does also fit with late
Lutetian (ca. 43–41 Ma) reports of initial glacio-eustatic
effects (Kominz et al., 2008; Gasson et al., 2012) and
cooling of ocean surface waters (Tripati et al., 2005;
Edgar et al., 2007; Tripati et al., 2008; Villa et al., 2008).
However, comparison to the stacked Eocene oxygen isotope curve (Zachos et al., 2008) shows that there is no
profound negative shift around the time of the ca. 41 Ma
sea retreat such that a link to global eustatic forcing cannot be convincingly established at this stage.
In contrast, the major disconformity found in the Aertashi section may be more straightforwardly linked to the
~70 m global sea-level fall at the ca. 34 Ma EOT (e.g.
Pekar et al., 2002; Miller et al., 2005; Katz et al., 2008;
Lear et al., 2008), globally associated to base-level falls
expressed by major disconformities. In the basins of the
Black Sea and South Caspian Sea the widespread organicrich and mud-prone sedimentation during the latest
Eocene and early Oligocene has been associated to the
EOT and interpreted as representing the birth of the Paratethys Sea (e.g. Baldi, 1984; Rusu, 1985; Dercourt,
1993; Robinson et al., 1996; R€ogl, 1999; Schulz et al.,
2005; Vincent et al., 2005; Allen & Armstrong, 2008;
Popov et al., 2008; Johnson et al., 2009). A shallow epicontinental basin like the Tarim Basin would have been
particularly sensitive to such a major base-level drop,
resulting in basinwide nondeposition or erosion, as
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
635
R. Bosboom et al.
evidenced by the major ca. 3.5 Myr hiatus across the
EOT. The disconformity suggests that until the ca.
34 Ma EOT the Tarim Basin did remain hydrologically
connected to the global ocean through the Western
Tethys. Unlike its present-day internal drainage configuration, the Tarim Basin was during Eocene times not disconnected from the Central Asian Ferghana and AfghanTajik Basins further to the west (Fig. 1), such that uplift
and topographic expression of the Pamir and West Kunlun Shan system was not yet significant enough to result
in basin closure. This is in agreement with reported evidence of limited Eocene Parmir–Kunlun tectonism from
stable isotope, provenance, thermochronologic and backstripping studies (Sobel & Dumitru, 1997; Yang & Liu,
2002; Cowgill, 2010; Bershaw et al., 2012) and our stratigraphic record at Aertashi showing that coarse-grained
basin infilling did not occur until the early Oligocene
(base C12r).
CONCLUSIONS
Our now more refined stratigraphic framework indicates
that the fourth regression in the Tarim Basin occurred
during the latest Lutetian–earliest Bartonian (ca. 41 Ma)
and was likely caused by both long-term aggradational
infilling controlled by early Tibetan Plateau and shortterm eustatic sea-level fluctuations. The disconformity
identified in the overlying continental deposits across the
EOT shows that the basin remained connected to the
global ocean through the Western Tethys until the earliest Oligocene and was indeed sensitive to global sea-level
fluctuations, confirming that uplift of the Pamir-Kunlun
system was not of importance yet. The sea retreat at ca.
41 Ma and the disconformity at the EOT both coincide
with indications of significant aridification steps in the
Asian interior. This correspondence suggests that, in line
with climate modelling results, the sea functioned as an
important moisture source for the Asian interior, which
allows future studies of Asian palaeoenvironmental
change to be interpreted in terms of fluctuations in moisture supply by the changing palaeogeography of the sea
in Central Asia. Further constraints on the forcing mechanisms behind the sea retreat and its palaeoenvironmental impact will arise from prospect studies on the early
exhumation history of the Pamir-Kunlun system as well
as improved age control of the youngest marine sediments in the westernmost Tarim Basin, the Alai Valley,
the Ferghana Basin and the Afghan-Tajik Basin (Tang
et al., 1989; Lan & Wei, 1995; Burtman et al., 1996;
Burtman, 2000; Coutand et al., 2002; Bosboom et al.,
2013).
ACKNOWLEDGEMENTS
This project was funded by the Netherlands Organization
for Scientific Research (NWO) and the Molengraaff Fund
636
(STMF) with grants to Roderic Bosboom and Guillaume
Dupont-Nivet. We are grateful to the CaiYanpei programme of EGIDE/Campus France for collaborative
support. We thank Cor Langereis, Laurie Bougeois, Gloria Heilbronn, Beibei Zhu and Ziya Yang for their contributions in the field, Tom Mullender and Mark Dekkers
for their assistance in the palaeomagnetic laboratory,
Giovanna Gianelli for nannofossil sample preparation,
Natasja Welters for technical support during palynological sample preparation, Hemmo Abels for providing the
composite lithostratigraphic log of the Xining basin and
Sander Houben for valuable comments on the manuscript. There is no conflict of interest among the authors.
SUPPORTING INFORMATION
Additional Supporting Information may be found in the
online version of this article:
Figure. S1. Plates showing the most important species
of calcareous nannofossils recognized. (1, 2) Lanternithus
arcanus, X nicols (KZ-B’-094’); (3) Zygrablithus bijugatus,
X nicols (KZ-B’000’); (4) Reticulofenestra minuta, X nicols
(KZ-B’-094’), X nicols; (5, 6) Ponthospahera exilis, X nicols (KZ-B’000’); (7, 10) Reticulofenestra samudorovi, X
nicols (AT-B02); (8, 9) Reticulofenestra umbilicus, X nicols
(AT-B02); (11) Dictyococcites sp., X nicols (AT-B02); (12)
Reticulofenestra sp. >5 mm, X nicols (ATB02).
Figure. S2a. Plates showing light photomicrographs of
key dinoflagellate cysts species, green algae and pollen
recognized. The bar for scale applies to all photographed
specimens, apart from 13. (1) Adnatosphaeridium williamsii
(AT-B02); (2) Fragment of Areosphaeridium diktyoplokum
(KY-B09); (3) Charlesdowniea wulagenensis (KY-B07);
Cyclonephelium/Caningia cpx (KY-B07); (5) Cordosphaeridium spp. (KY-B07); (6) Cordosphaeridium funiculatum
(KZ-B’-087′); (7) Cerodinium sp. (KY-B07); (8) Dapsilidinium pseudocolligerum (AT-B37); (9) Deflandrea spp. (ATB37); (10) Enneadocysta pectiniformis (KY-B09).
Figure. S2b. Continued from Fig. S2a. (11) Homotryblium spp. (KY-B07); (12) Hystrichosphaeropsis rectangularis (KY-B07); (13) Fragment of Melitasphaeridium
pseudorecurvatum (KY-B07); (14) Impagidinium brevisulcatum (AT-B02); (15) Selenopemphix nephroides (AT-B37);
(16) Rhombodinium draco (AT-B37); (17) Melitasphaeridium pseudorecurvatum (KY-B07); (18) Dapsilidinium
pseudocolligerum (KY-B07); (19) Deflandrea spp.
(AT-B37); (20) Thalassiphora spp. (KY-B07); (21)
Tasmaniceae (prasinophyte algae) (AT-B37); (22) Pinus
pollen (KY-B07). (23) Pollen sp. (AT-B02).
Table S1. Mollusk content of examined samples. c,
common; f, frequent; r, rare; x, present, brackets for
uncertain identification.
Table S2. Range chart of recognized calcareous nannofossils. The numbers correspond to counted specimens in
400 Fields of view at 1009. Dark grey cells correspond to
barren samples and white to fossiliferous marine samples.
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
Table S3. Range chart of recognized palynomorphs.
Dark-shaded cells correspond to barren, light-shaded
to almost barren and nonshaded to fossiliferous marine
samples.
Table S4. Declination and inclination of ChRM directions in in situ (IS) and tilt-corrected (TC) coordinates for
the Kezi (KZ) section. MAD is the mean angular
deviation. ChRM directions obtained by great circle
analysis are indicated by # and forced line-fits by *.
Directions rejected by a 45° cut-off angle (Deenen et al.,
2011) are printed in bold.
Table S5. Declination and inclination of ChRM directions in in situ (IS) and tilt-corrected (TC) coordinates for
the Aertashi (AT) section. MAD is the mean angular
deviation. ChRM directions obtained by great circle
analysis are indicated by # and forced line-fits by *.
Directions rejected by a 45° cut-off angle (Deenen et al.,
2011) are printed in bold.
REFERENCES
ABELS, H.A., DUPONT-NIVET, G., XIAO, G., BOSBOOM, R.E. &
KRIJGSMAN, W. (2011) Step-wise Asian paleoenvironmental
changes preceding the Eocene–Oligocene Transition (Eot) in
the terrestrial Xining Basin, China. Palaeogeogr. Palaeoclimatol. Palaeoecol., 299, 399–412.
AIGNER, T., BRANDENBURG, A., van VLIET, A., LAWRENCE, D. &
WESTRICH, J. (1990) Stratigraphic modelling of epicontinental
basins: two applications. Sed. Geol., 69, 167–190.
AKHMETIEV, M.A. (2007) Paleocene and Eocene floras of Russia
and adjacent regions: climatic conditions of their development. Paleontol. J., 41, 1032–1039.
AKHMETIEV, M.A. & BENIAMOVSKI, V.N. (2006) The Paleocene
and Eocene in the Russian part of West Eurasia. Stratigr.
Geol. Correl., 14, 49–72.
ALLEN, M.B. & ARMSTRONG, H.A. (2008) Arabia-Eurasia collision and the forcing of mid-Cenozoic global cooling. Palaeogeogr. Palaeoclimatol. Palaeoecol., 265, 52–58.
AMIDON, W.H. & HYNEK, S.A. (2010) Exhumational history of
the north central Pamir. Tectonics, 29, TC5017.
, T. (1984) The terminal Eocene and Early Oligocene
BALDI
events in Hungary and the separation of an anoxic, cold paratethys. Eclogae Geol. Helv., 77, 1–27.
BERSHAW, J., GARZIONE, C.N., SCHOENBOHM, L., GEHRELS, G. &
TAO, L. (2012) Cenozoic evolution of the Pamir Plateau based
on stratigraphy, zircon provenance, and stable isotopes of
foreland basin sediments at Oytag (Wuyitake) in the Tarim
Basin (West China). J. Asian Earth Sci., 44, 136–148.
€ Versteiner€
B€ohm, J. (ed.) (1903) Uber
Cretaceische Und EocAne
ungen Aus Fergana. Durch Asien. Reimer, Berlin.
BOOS, W.R. & KUANG, Z. (2010) Dominant control of the South
Asian Monsoon by orographic insulation versus plateau heating. Nature, 463, 218–223.
BOSBOOM, R.E., DUPONT-NIVET, G., HOUBEN, A.J.P., BRINKHUIS, H., VILLA, G., MANDIC, O., STOICA, M., ZACHARIASSE,
W.-J., GUO, Z. & LI, C. (2011) Late Eocene sea retreat from
the Tarim Basin (west China) and concomitant Asian paleoenvironmental change. Palaeogeogr. Palaeoclimatol. Palaeoecol., 299, 385–398.
BOSBOOM, R.E., DUPONT-NIVET, G., GROTHE, A., BRINKHUIS,
H., VILLA, G., MANDIC, O., BOUGEOIS, L., STOICA, M., KOUWENHOVEN, T., AMINOV, J., RAJABOV, N., MAMADJANOV, Y.,
OYMAHMADOV, I. & ORMUKOV, C. (2013) Early Paratethys
Paleogeography in Central Asia (Sw Tajikistan, S Kyrgyzstan
and Nw China) During the Paleogene. Darius Programme Central Asia Workshop, 2013 February 26–27, Bone, Germany.
BOWN, P. (2005) Paleogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania: Tanzania drilling project sites 1 to 10. J. Nannoplankton Res., 27, 21–95.
BOWN, P.R. & YOUNG, J.R. (1998) Introduction. In: Calcareous
Nannofossil Biostratigraphy: British Micropalaeontology Society
Series (Ed. by P.R. Bown), pp. 1–15. Chapman and Hall,
London.
BRINKHUIS, H. (1994) Late Eocene to Early Oligocene dinoflagellate cysts from the Priabonian type-area (Northeast Italy):
biostratigraphy and paleoenvironmental interpretation. Palaeogeogr. Palaeoclimatol. Palaeoecol., 107, 121–163.
BRINKHUIS, H. & BIFFI, U. (1993) Dinoflagellate cyst stratigraphy of the Eocene/Oligocene transition in central Italy. Mar.
Micropaleontol., 22, 131–183.
BUDD, D.A. & HARRIS, P.M., eds. (1990) Carbonate-Siliciclastic
Mixtures. Sepm Reprint Series Number 14. SEPM, Tulsa,
Oklahoma.
BURTMAN, V.S. (2000) Cenozoic crustal shortening between the
Pamir and Tien Shan and a reconstruction of the Pamir–Tien
Shan transition zone for the Cretaceous and Palaeogene. Tectonophysics, 319, 69–92.
BURTMAN, V.S. & MOLNAR, P. (1993) Geological and geophysical evidence for deep subduction of continental crust beneath
the Pamir. Geol. Soc. Am. Spec. Pap., 281, 76.
BURTMAN, V.S., SKOBELEV, S.F. & MOLNAR, P. (1996) Late
Cenozoic slip on the Talas-Ferghana Fault, the Tien Shan,
central Asia. Geol. Soc. Am. Bull., 108, 1004–1021.
CLARK, M.K., FARLEY, K.A., ZHENG, D., WANG, Z. & DUVALL,
A.R. (2010) Early Cenozoic faulting of the northern Tibetan
Plateau margin from apatite (U-Th)/He Ages. Earth Planet.
Sci. Lett., 296, 78–88.
COUTAND, I., STRECKER, M.R., ARROWSMITH, R., HILLEY, G.,
THIEDE, R.C., KORJENKOV, A. & OMURALIEV, M. (2002) Late
Cenozoic tectonic development of the intramontane Alai Valley, (Pamir-Tien Shan Region, Central Asia): an example of
intracontinental deformation due to the Indo-Eurasia Collision. Tectonics, 21, 3-1–3-19.
COWGILL, E. (2010) Cenozoic right-slip faulting along the eastern margin of the Pamir salient, northwestern China. Geol.
Soc. Am. Bull., 122, 145–161.
DEENEN, M.H.L., LANGEREIS, C.G., VAN HINSBERGEN, D.J.J. &
BIGGIN, A.J. (2011) Geomagnetic secular variation and the
statistics of palaeomagnetic directions. Geophys. J. Int., 186,
509–520.
DEQUAN, Y., XIAOCHUN, Z., YIMIN, Y., FAN, Y., SHIBEN, Z.,
ZHONGXIONG, J., YICHEN, W., ZHENCHENG, S., SHIZHONG, Y.,
XIULAN, Z., HOU, S., HONGDE, L., WENSONG, T., XUETING,
G. & CHUANBEN, Z. (1996) Tertiary in Petroliferous Regions of
China. Petroleum Industry Press, Beijing.
Dercourt, J., Ricou, L.E. & Vrielynck, B. (eds.) (1993) Atlas
Tethys Paleoenvironmental Maps. Commision for the Geological Map of the World, Paris.
DESIO, A. & MARTINA, E. (1975) Some stratigraphical sequences
of Katagan and surrounding regions. In: Geology of Central
Badakhshan: Italian Expeditions to the Karakorum (K2), and Hindu
Kushvol. III/3 (Ed. by A. Desio, ), pp. 94–155. Brill, Leiden.
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
637
R. Bosboom et al.
Ene.
DUCASSE, O., GUERNET, C. & AMBAREAU, Y. (1985) PalEog
In: Atlas Des Ostracodes De France (Ed. by H.J. Oertli) MEm.,
9, 257–311.
DUPONT-NIVET, G., KRIJGSMAN, W., LANGEREIS, C.G., ABELS,
H.A., DAI, S. & FANG, X. (2007) Tibetan plateau aridification
linked to global cooling at the Eocene–Oligocene transition.
Nature, 445, 635–638.
DUPONT-NIVET, G., HOORN, C. & KONERT, M. (2008) Tibetan
uplift prior to the Eocene-Oligocene climate transition: evidence from pollen analysis of the Xining Basin. Geology, 36,
987–990.
EDGAR, K.M., WILSON, P.A., SEXTON, P.F. & SUGANUMA, Y.
(2007) No extreme bipolar glaciation during the main Eocene
calcite compensation shift. Nature, 448, 908–911.
FENSOME, R.A. & WILLIAMS, G.L. (2004) The Lentin and
Williams Index of Fossil Dinoflagellates. American Association
of Stratigraphic Palynologists Foundation Contr. Ibutions
Series, Salt Lake City.
FISHER, R.A. (1953) Dispersion on a sphere. Proc. Roy. Soc. London Ser. A Math. Phys. Sci., 217, 295–305.
GAO, Z., CHEN, K. & WEI, J. (2000) The Lithostratigraphic Dictionary of China. China University of Geosciences Press,
Wuhan.
GARZIONE, C., IKARI, M.J. & BASU, A.R. (2005) Source of
Oligocene to Pliocene sedimentary rocks in the Linxia
basin in northeastern Tibet from Nd isotopes: implications
for tectonic forcing of climate. Geol. Soc. Am. Bull., 117,
1156–1166.
GASSON, E., SIDDALL, M., LUNT, D.J., RACKHAM, O.J.L., LEAR,
C.H. & POLLARD, D. (2012) Exploring uncertainties in the
relationship between temperature, ice volume, and sea level
over the past 50 million years. Rev. Geophys., 50, 1–35.
GOMES-RODRIGUES, H., MARIVAUX, L. & VIANEY-LIAUD, M.
(2012) Expansion of open landscapes in Northern China during the Oligocene induced by dramatic climate changes:
paleoecological evidence. Palaeogeogr. Palaeoclimatol. Palaeoecol., 358–360, 62–71.
GORIZDRO, S.F. (1913) Material for the Tertiary Turkestan
Fauna Study: Trudy I. Petrogradskago Obshestva Estestvoispitatelei. Otd. geol. i min, 37, 1–57.
GRADSTEIN, F.M., OGG, J.G., SCHMITZ, M. & OGG, G. (2012)
The geologic Time Scale 2012. Elsevier, Cambridge University
Press, Cambridge.
GRAHAM, S.A. (1987) Tectonic controls on petroleum occurrence in central California. In: Cenozoic Basin Development of
Coastal California (Ed. by R.V. Ingersoll & W.G. Ernst)
Rubey, VI, 47–63.
GRAHAM, S.A., CHAMBERLAIN, C.P., YUE, Y.J., RITTS, B.D.,
HANSON, A.D., HORTON, T.W., WALDBAUER, J.R., POAGE,
M.A. & FENG, X. (2005) Stable isotope records of Cenozoic
climate and topography, Tibetan Plateau and Tarim Basin.
Am. J. Sci., 305, 101–118.
GUO, X. (1991) An approach to the depositional environment of
the Cretaceous Kizilsu Group: the lowermost marine horizon
of the Cretaceous in the western Tarim Basin. Acta Geol. Sinica, 2, 188–198.
HAO, Y.C. & ZENG, X.L. (1984) On the evolution of the West
Tarim Gulf from Mesozoic to Cenozoic in terms of characteristics of foraminiferal fauna. Acta Micropalaeontol. Sinica, 1,
1–13.
HENDRIX, M.S., GRAHAM, S.A., CARROLL, A.R., SOBEL, E.R.,
MCKNIGHT, C.L., SCHULEIN, B.J. & WANG, Z. (1992)
Sedimentary record and climatic implications of recurrent
638
deformation in the Tian Shan: evidence from Mesozoic Strata
of the north Tarim, South Junggar, and Turpan Basins,
Northwest China. Geol. Soc. Am. Bull., 104, 53–79.
van HINSBERGEN, D.J.J., LIPPERT, P.C., DUPONT-NIVET, G.,
MCQUARRIE, N., DOUBROVINE, P.V., SPAKMAN, W. & TORSVIK, T.H. (2012) Greater India Basin hypothesis and a
two-stage Cenozoic collision between India and Asia. Proc.
Natl Acad. Sci., 109, 7659–7664.
HOORN, C., STRAATHOF, J., ABELS, H.A., YADONG, X., UTESCHER, T. & DUPONT-NIVET, G. (2012) Late Eocene palynological record of climate change and Tibetan Plateau uplift
(Xining Basin, China). Palaeogeogr. Palaeoclimatol. Palaeoecol., 344–345, 16–38.
HOUBEN, A.J.P., BIJL, P.K., GUERSTEIN, G.R., SLUIJS, A. &
BRINKHUIS, H. (2011) Malvinia escutiana, a new biostratigraphically important Oligocene dinoflagellate cyst from the
Southern Ocean. Rev. Palaeobot. Palynol., 165, 175–182.
IAKOVLEVA, A.I. & HEILMANN-CLAUSEN, C. (2010) Eocene
dinoflagellate cyst biostratigraphy of research borehole 011Bp, Omsk Region, southwestern Siberia. Palynology, 34,
195–232.
Jia, C., Wei, G., Wang, L., Jia, D. & Guo, Z. (eds.) (1997) Tectonic Characteristics and Petroleum, Tarim Basin, China. Petroleum Industry Press, Beijing.
JIA, C., ZHANG, S. & WU, S. (2004) Stratigraphy of the Tarim
Basin and Adjacent Areas. Science Press, Beijing.
JIN, X., WANG, J., CHEN, B. & REN, L. (2003) Cenozoic depositional sequences in the piedmont of the west Kunlun and their
paleogeographic and tectonic implications. J. Asian Earth
Sci., 21, 755–765.
JOHNSON, C.L., HUDSON, S.M., ROWE, H.D. & EFENDIYEVA,
M.A. (2009) Geochemical constraints on the Palaeocene–
Miocene evolution of eastern Azerbaijan, with implications
for the South Caspian Basin and eastern Paratethys. Basin
Res., 22, 733–750.
JOLIVET, M., BRUNEL, M., SEWARD, D., XU, Z., YANG, J., ROGER,
F., TAPPONNIER, P., MALAVIEILLE, J., ARNAUD, N. & WU, C.
(2001) Mesozoic and Cenozoic tectonics of the northern edge
of the Tibetan Plateau: fission-track constraints. Tectonophysics, 343, 111–134.
KATZ, M.E., MILLER, K.G., WRIGHT, J.D., WADE, B.S., BROWNING, J.V., CRAMER, B.S. & ROSENTHAL, Y. (2008) Stepwise
transition from the Eocene greenhouse to the Oligocene icehouse. Nat. Geosci., 1, 329–334.
KEEN, M.C. (1978) The Tertiary- Paleogene. In: A Stratigraphical Index of British Ostracoda (Ed. by R.H. Bate, E. Robinson),
pp. 385–449. Seel House Press, Liverpool.
KEIJ, A.J. (1957) Eocene and Oligocene Ostracoda of Belgium.
MEmoires
Institut Royal des Sciences Naturelles de Belgique), Brussels.
KENT-CORSON, M.L., RITTS, B.D., ZHUANG, G., BOVET, P.M.,
GRAHAM, S.A. & PAGE CHAMBERLAIN, C. (2009) Stable isotopic constraints on the tectonic, topographic, and climatic evolution of the northern margin of the Tibetan Plateau. Earth
Planet. Sci. Lett., 282, 158–166.
KIRSCHVINK, J.L. (1980) The least-square line and plane and the
analysis of paleomagnetic data. Geophys. J. Roy. Astron. Soc.,
62, 699–718.
KOMINZ, M.A., BROWNING, J.V., MILLER, K.G., SUGARMAN,
P.J., MIZINTSEVA, S. & SCOTESE, C.R. (2008) Late Cretaceous
to Miocene Sea-Level estimates from the New Jersey and
Delaware coastal plain coreholes: an error analysis. Basin Res.,
20, 211–226.
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Tarim Basin sea retreat
KRAATZ, B.P. & GEISLER, J.H. (2010) Eocene-Oligocene transition in central Asia and its effects on mammalian evolution.
Geology, 38, 111–114.
KUTZBACH, J.E., GEUTTER, P.J., RUDDIMAN, W.F. & PRELL,
W.L. (1989) Sensitivity of climate to late Cenozoic uplift in
southern Asia and the Amercian West: numerical experiments. J. Geophys. Res., 94, 18,393–318,407.
LAN, X. (1997) Paleogene bivalve communities in the western
Tarim Basin and their paleoenvironmental implications. Paleoworld, 7, 137–157.
LAN, X. & WEI, J. (eds.) (1995) Late Cretaceous-Early Tertiary
Marine bivalve fauna from the Western Tarim Basin. Chinese
Science Publishing House, Beijing.
LEAR, C.H., BAILEY, T.R., PEARSON, P.N., COXALL, H.K. & ROSENTHAL, Y. (2008) Cooling and ice growth across the
Eocene-Oligocene transition. Geology, 36, 251–254.
LORD, A.R., WHITTACKER, J.E. & KING, C. (2009) Paleogene. In:
Ostracods in British Stratigraphy (Ed. by J.E. Whitaker &
M.B. Hart), pp. 374–409. The Micropaleontological Society,
Special Publications, London.
MAO, S. & NORRIS, G. (1988) Late Cretaceous-Early Tertiary Dinoflagellates and Acritarchs from the Kashi Area, Tarim Basin,
Xinjiang Province, China. Royal Ontario Museum, Toronto.
MARTINI, E. (1971) Standard Tertiary and Quaternary calcareous nannoplankton zonation. In: Proceedings 2nd International
Conference Planktonic Microfossils (Ed. by A. Farinacci) Roma,
2, 739–785.
MCFADDEN, P.L. & MCELHINNY, M.W. (1988) The combined
analysis of remagnetization circles and direct observations in
palaeomagnetism. Earth Planet. Sci. Lett., 87, 161–172.
MCFADDEN, P.L. & MCELHINNY, M.W. (1990) Classification of
the reversal test in palaeomagnetism. Geophys. J. Int., 103,
725–729.
MENG, Z., DENG, Y., DING, Z., LI, Y. & SUN, D. (1998) New
paleomagnetic results from Ceno-Mesozoic volcanic rocks
along southern rim of the Tarim Basin, China. Sci. China Ser.
D Earth Sci. (English edition), 41, 91–104.
MILLER, K.G., KOMINZ, M.A., BROWNING, J.V., WRIGHT, J.D.,
MOUNTAIN, G.S., KATZ, M.E., SUGARMAN, P.J., CRAMER,
B.S., CHRISTIE-BLICK, N. & PEKAR, S.F. (2005) The phanerozoic record of global sea-level change. Science, 310, 1293–
1298.
MOURIK, C.A.V. & BRINKHUIS, H. (2005) The Massignano
Eocene–Oligocene golden spike section revisited. Stratigraphy, 2, 13–30.
MULLENDER, T.A.T., van VELZEN, A.J. & DEKKERS, M. (1993)
Continuous drift correction and separate identification of ferromagnetic and paramagnetic contribution in thermomagnetic runs. Geophys. J. Int., 114, 663–672.
OKADA, H. & BUKRY, D. (1980) Supplementary modification
and introduction of code numbers to the low latitude coccolith biostratigraphic zonation (Bukry 1973, 1975). Mar. Micropaleontol., 5, 321–325.
PASSIER, H.F., de LANGE, G.J. & DEKKERS, M.J. (2001) Magnetic properties and geochemistry of the active oxidation front
and the youngest sapropel in the eastern Mediterranean sea.
Geophys. J. Int., 145, 604–614.
PEKAR, S.F., CHRISTIE-BLICK, N., KOMINZ, M.A. & MILLER,
K.G. (2002) Calibration between eustatic estimates from
backstripping and oxygen isotopic records for the Oligocene.
Geology, 30, 903.
PIETRZENIUK, E. (1969) Taxonomische Und Biostratigraphishe
€ 5 Im Norden Der
Untersuchungen an Ostracoden Des EozAn
€
Deutschen Demokratischen Republik. PalAontologische
Ab€
handlungen Abteilung A: PalAozoologie,
Berlin.
PIRKENSEER, C. & BERGER, J.P. (2011) Paleogene Ostracoda from
the Southern Upper Rhine Graben: Taxonomy, Palaeogeoecology and Palaeobiogeography. Palaeontographica, Abteilung A,
295, 1–149.
€
POPOV, S., ROGL
, F., ROZANOV, A.Y., STEININGER, F.F., SHCHERBA, I.G. & KOVAC, M. (2004) Lithological–Paleogeographic
maps of Paratethys 10 Maps Late Eocene to Pliocene. Cour.
Forsch. Senckenb., 250, 1–42.
POPOV, S.V., SYCHEVSKAYA, E.K., AKHMETIEV, M.A., ZAPOROZHETS, N.I. & GOLOVINA, L.A. (2008) Stratigraphy of the maikop group and pteropoda beds in northern azerbaijan.
Stratigr. Geol. Correl., 16, 664–677.
POPOV, S.V., ANTIPOV, M.P., ZASTROZHNOV, A.S., KURINA, E.E.
& PINCHUK, T.N. (2010) Sea-level fluctuations on the northern shelf of the eastern paratethys in the Oligocene–Neogene.
Stratigr. Geol. Correl., 18, 200–224.
PRELL, W.L. & KUTZBACK, J.E. (1992) Sensitivity of the indian
monsoon to forcing parameters and implications for its evolution. Nature, 360, 647–652.
QUAN, C., LIU, Y.S.C. & UTESCHER, T. (2011) Paleogene evolution of precipitation in northeastern china supporting the
middle eocene intensification of the East Asian monsoon. Palaios, 26, 743–753.
QUAN, C., LIU, Y.-S.C. & UTESCHER, T. (2012) Paleogene temperature gradient, seasonal variation and climate evolution of
northeast China. Palaeogeogr. Palaeoclimatol. Palaeoecol.,
313–314, 150–161.
RAMSTEIN, G., FLUTEAU, F., BESSE, J. & JOUSSAUME, S. (1997)
Effect of orogeny, plate motion and land–sea distribution on
Eurasian climate change over the past 30 million years. Nature, 386, 788–795.
Reading, H.G. (ed.) (2006) Sedimentary Environments: Processes Facies and Stratigraphy. Blackwell Publishing Inc.,
Oxford.
RITTS, B.D., YUE, Y., GRAHAM, S.A., SOBEL, E.R., ABBINK, O.A.
& STOCKLI, D. (2008) From sea level to high elevation in 15
million years:uplift history of the northern Tibetan Plateau
margin in the Altun Shan. Am. J. Sci., 308, 657–678.
ROBINSON, A.G., RUDAT, J.H., BANKS, C.J. & WILES, R.L.F.
(1996) Petroleum geology of the black sea. Mar. Petrol. Geol.,
13, 195–223.
ROBINSON, D.M., DUPONT-NIVET, G., GEHRELS, G.E. & ZHANG,
Y. (2003) The Tula Uplift, northwestern China; evidence for
regional tectonism of the northern Tibetan Plateau during late
Mesozoic–early Cenozoic time. Geol. Soc. Am. Bull., 115,
35–47.
€
ROGL
, F. (1999) Short note: Mediterranean and Paratethys. facts
and hypotheses of an Oligocene to Miocene Paleogeography
(short overview). Geol. Carpath., 50, 339–349.
RUDDIMAN, W.F. & KUTZBACH, J.E. (1989) Forcing of late Cenozoic northern hemisphere climate by plateau uplift in southern Asia and the American West. J. Geophys. Res., 94,
18,409–18,427.
RUSU, A. (1985) Oligocene events in Transylvania (Romania)
and the first separation of Paratethys. DS Inst. Geol. Geofiz.,
72–73, 207–223.
RUSU, A., BROTEA, D. & MELINTE, M.C. (2004) Biostratigraphy
area (NW Transylvania,
of the bartonian deposits from GilAu
Romania). Acta Palaeontol. Romaniae, 4, 441–454.
SCHULZ, H.-M., BECHTEL, A. & SACHSENHOFER, R.F. (2005) The
birth of the Paratethys during the Early Oligocene: from
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
639
R. Bosboom et al.
Tethys to an ancient Black Sea analogue? Global Planet.
Change, 49, 163–176.
SHELDON, E. (2002) Palaeogene nannofossil biostratigraphy of
^
the KangAmiut-1
and Nukik-2 wells, offshore West Greenland. Mar. Petrol. Geol., 20, 1031–1041.
SOBEL, E.R. & DUMITRU, T.A. (1997) Thrusting and exhumation around the margins of the western Tarim basin
during the India-Asia collision. J. Geophys. Res., 102, 5043–
5063.
STENZEL, H.B. (1971) Oysters. In: Treatise on Invertebrate
Paleontology (Ed. by R.C. Moore), pp. 953–1224. Vol. 3.
Geological Society of America, Boulder, CO and University
of Kansas Press, Lawrence, KS.
SUN, X. & WANG, P. (2005) How old is the Asian monsoon system? Palaeobotanical records from China. Palaeogeogr. Palaeoclimatol. Palaeoecol., 222, 181–222.
SZCZECHURA, J. (1977) Ostracods from the Upper Eocene of East
Poland. Acta Palaeontol. Pol., 22, 55–92.
TANG, T., YANG, H., LAN, X., YU, C., XUE, Y., ZHANG, Y., HU,
L., ZHONG, S. & WEI, J. (1989) Marine Late Cretaceous and
Early Tertiary stratigraphy and Petroleum Geology in Western
Tarim Basin, China. Science Press, Beijing.
TANG, T., XUE, Y. & YU, C. (1992) Characteristics and Sedimentary Environments of the Late Cretaceous to Early Tertiary
Marine Strata in the Western Tarim, China. Science Press,
Beijing.
THOMAS, J.-C., CHAUVIN, A., GAPAIS, D., BAZHENOV, M.L.,
PERROUD, H., COBBOLD, P.R. & BURTMAN, V.S. (1994)
Paleomagnetic evidence for cenozoic block rotations in the
Tadjik depression (Central Asia). J. Geophys. Res., 99, 15141–
15160.
TIAN, Z., CHAI, G. & KANG, Y. (1989) Tectonic evolution of the
Tarim Basin. In: Chinese Sedimentary Basins (Ed. by X. Zhu),
Sed. Basins World, 1, 33–42.
TRIPATI, A., BACKMAN, J., ELDERFIELD, H. & FERRETTI, P. (2005)
Eocene bipolar glaciation associated with global carbon cycle
changes. Nature, 436, 341–346.
TRIPATI, A.K., EAGLE, R.A., MORTON, A., DOWDESWELL, J.A.,
ATKINSON, K.L., BAHE , Y., DAWBER, C.F., KHADUN, E.,
SHAW, R.M.H. & SHORTTLE, O. (2008) Evidence for glaciation
in the Northern hemisphere back to 44 Ma from Ice-Rafted
Debris in the Greenland Sea. Earth Planet. Sci. Lett., 265,
112–122.
VAROL, Q. (1998) Palaeogene. In: Calcareous Nannofossil Biostratigraph Y British Micropal (Ed. by P.R. Brown), pp. 200–
224. Chapman & Hall/Kluwer Academic, New York.
VILLA, G., FIORONI, F., PEA, L., BOHATY, S. & PERSICO, D.
(2008) Middle Eocene–Late Oligocene climate variability: calcareous nannofossil response at Kerguelen Plateau, Site 748.
Mar. Micropaleontol., 69, 173–192.
VINCENT, S.J., ALLEN, M.B., ISMAIL-ZADEH, A.D., FLECKER, R.,
FOLAND, K.A. & SIMMONS, M.D. (2005) Insights from the
640
Talysh of Azerbaijan into the Paleogene evolution of the
South Caspian region. GSA Bull., 117, 1513–1533.
VYALOV, O.S. (1937) Sur La Clasification Des Ostreides Et Leur
Valeur Stratigraphique, Intern. Congr. Zool., Lisbonne, 1627–
1638.
WANG, C., HONG, H., LI, Z., YIN, K., XIE, J., LIANG, G., SONG,
B., SONG, E. & ZHANG, K. (2012) The Eocene–Oligocene climate transition in the Tarim Basin, Northwest China: evidence from clay mineralogy. Appl. Clay Sci., 74, 10–19.
YANG, Y. & LIU, M. (2002) Cenozoic deformation of the Tarim
Plate and the implications for mountain building in the Tibetan Plateau and the Tian Shan. Tectonics, 21, 1059.
YANG, H., JIANG, X. & LIN, S. (1995) Late Cretaceous- Early
Tertiary Ostracod Fauna from Western Tarim Basin, South
Xinjiang, China. Science Press, Beijing.
YANG, H.J., SHEN, J.W., ZHANG, L.J., LI, M., HUANG, Z.B. &
WANG, Y. (2012) Serpulids and their paleoecology of the
Paleogene Kalatar formation in southwest Tarim Basin of
China. Sci. China Earth Sci., 55, 1087–1100.
_ (2009) Ostracoda
YESß ILYURT, N., TUNOGLU
, C. & ERTEKIN, I.
assemblage and environmental interpretation of the Bartonian–Priabonian Seydiler Formation (Kastamonu-Northern
Turkey). Geol. Bull. Turk., 52, 20–85.
YIN, A. & HARRISON, M.T. (2000) Geologic Evolution of the
Himalayan-Tibetan orogen. Annu. Rev. Earth Planet. Sci., 28,
211–280.
YIN, A., RUMELHART, P.E., BUTLER, R.F., COWGILL, E., HARRISON, T.M., FOSTER, D.A., INGERSOLL, R.V., ZANG, Q., ZHOU,
X.-Q., WANG, X.-F., HANSON, A. & RAZA, A. (2002) Tectonic
history of the Altyn Tagh fault system in northern Tibet
inferred from Cenozoic sedimentation. Geol. Soc. Am. Bull.,
114, 1257–1295.
ZACHOS, J.C., DICKENS, G.R. & ZEEBE, R.E. (2008) An early
Cenozoic perspective on greenhouse warming and carboncycle dynamics. Nature, 451, 279–283.
ZHANG, Z., WANG, H., GUO, Z. & JIANG, D. (2007) What triggers the transition of palaeoenvironmental patterns in China,
the Tibetan Plateau uplift or the Paratethys Sea retreat? Palaeogeogr. Palaeoclimatol. Palaeoecol., 245, 317–331.
ZHANG, Z., FLATØY, F., WANG, H., BETHKE, I., BENTSEN, M. &
GUO, Z. (2012) Early Eocene Asian climate dominated by desert and steppe with limited monsoons. J. Asian Earth Sci., 44,
24–35.
ZHENG, J., HE, X. & LIU, S. (1999) Dictionary of Chinese Stratigraphy-Tertiary. Geology Press, Beijing.
ZHONG, S. (1992) Calcareous Nannofossils from the Upper Cretaceous and Lower Tertiary in the Western Tarim Basin, South
Xinjiang, China. Chinese Science Publishing House, Beijing.
Manuscript received 16 May 2013; In revised form 21
September 2013; Manuscript accepted 05 October 2013.
© 2013 The Authors
Basin Research © 2013 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists