Download Geodynamic evolution of Central Asia in the Paleozoic and Mesozoic

Int J Earth Sci (Geol Rundsch) (2009) 98:1185–1188
DOI 10.1007/s00531-009-0418-4
EDITORIAL
Geodynamic evolution of Central Asia in the Paleozoic
and Mesozoic
Wenjiao Xiao Æ Alfred Kröner Æ Brian Windley
Published online: 31 January 2009
Ó Springer-Verlag 2009
Central Asia is an ideal laboratory to study geodynamics
and continental growth in the Phanerozoic (Şengör et al.
1993; Şengör and Natal’in 1996; Jahn et al. 2004; Xiao
et al. 2004a, b; Kröner et al. 2007; Windley et al. 2007;
Jian et al. 2008). Three important orogenic collages are
exposed in Central Asia, i.e. the Altaids or Central Asian
Orogenic Belt in the north, Tethysides in the south, and
Western Pacific orogenic collages in the east. The architecture of Central Asia was mainly constructed from the
interactions between these collages (Isozaki et al. 1990;
Şengör et al. 1993; Yin and Nie 1996; Maruyama 1997;
Xiao et al. 2008a, b).
The interaction among these collages was the major topic
of a 5-day thematic workshop on ‘‘Geodynamic Evolution
of Central Asia in the Paleozoic and Mesozoic’’, held in
Beijing, China, in December 2006 and funded by the SinoGerman Centre for Research Promotion (Chinesisch-Deutsches Zentrum für Wissenschaftsförderung) (Xiao and
W. Xiao (&)
State Key Laboratory of Lithospheric Evolution, Institute
of Geology and Geophysics, Chinese Academy of Sciences,
Beijing, China
e-mail: [email protected]
A. Kröner
Institut für Geowissenschaften, Universität Mainz,
Becherweg 21, 55099 Mainz, Germany
A. Kröner
SHRIMP Centre, Geological Institute, Chinese Academy
of Geological Sciences, Beijing, China
B. Windley
Department of Geology, University of Leicester,
Leicester LE1 7RH, UK
Kröner 2007). The workshop was attended by more than 50
participants representing eight countries (Germany, UK,
France, Russia, Australia, Italy, Cuba, and China) and was
co-sponsored jointly by Task Force I (Earth Accretionary
Systems) of the International Lithosphere Program (ILP),
IGCP Project 480, and the State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics,
Chinese Academy of Sciences (CAS).
The current thematic volume arises from this workshop
and also includes several invited contributions. The 18
papers in this volume reflect a relatively broad spectrum of
current research and cover regions in the southern Altaids
as well as the northern Tethysides and the Japan Islands
where the Altaids and Tethysides possibly join (Fig. 1).
Wenjiao Xiao and co-authors (this volume) synthesize
accretionary processes during final terrane amalgamation
in the Altai and Tien Shan Mountain Range of NW China
and Inner Mongolia in the late Permian to mid-Triassic.
They use structural, geochemical, geochronological and
palaeomagnetic data to show that there was continuous
southward accretion in the late Paleozoic to middle Triassic
of volcanic arcs, accretionary wedges and HP- to UHPmetamorphic rocks. Final closure of the Paleoasian Ocean
led to docking of the Tarim and North China Cratons with
the amalgamated CAOB terrranes and terminal orogenesis.
This complex geodynamic evolution led to formation of
major metal deposits and substantial crustal growth.
Jun Gao and co-authors (this volume) provide geochemical data and zircon ages for metaluminous to weakly
peraluminous granitoids in the southern Chinese Tianshan
and relate these to continental arc settings between ca. 480
and 275 Ma ago. These authors favor Silurian to Carboniferous northward subduction of the South Tianshan
oceanic plate beneath the southern margin of the Central
Tianshan-Kazakhstan-Yili continental plate and argue for
123
Int J Earth Sci (Geol Rundsch) (2009) 98:1185–1188
100
120
Sik h o t e- Alin
Angaran
Craton
x
40
Alai
Tu
rke
x xx
stan
Ulaanbataar
x
x
x
Bei Shan
Tarim Tien S
han
x
i l i Alax
W
a
.K
Q
ns
aida
x
unlun
ha
m
E. Ku
n
nlun
ib
e t (u
n d if
.)
m
a
I n
d i laa y a s
Sea
of
Japan
x
r
nke
Solo
Urumqi
x
x
140
x
Beijing
Q
ulu
S
North China
Qi n l i n g
Other orogenic collages
me
- Da
bi e
u
ng
Lo
Craton
n
T
Hi
Altaids
40
ar c
80
60
South China
ky
Ura EUC
ls
1186
Ry
u
20
Fig. 1 Schematic tectonic map of Central Asia showing the Altaids and other orogenic collages with contributions in this volume marked as
boxes or crosses (adapted from de Jong et al. 2006; Xiao et al. 2003, 2004a, 2008a). EUC East European Craton
completion of terrane accretion and collision in the
Permian.
Koen de Jong and co-authors (this volume) present
laser-probe dating of mylonite whole-rock samples from
the North Tianshan—Main Tianshan fault zone, represented by 40Ar/39Ar spectra with ages of 255–285 Ma. The
Permian ages of mylonites date movement on these ductile,
dextral strike-slip shear zones, whereas the mica ages are
interpreted to reflect recrystallisation as a result of fluid
flow around such transcurrent faults.
Wei Lin and co-authors (this volume) present a new
model for the polyphase structural evolution of the southwestern Chinese Tianshan, including a high-pressure
blueschist-eclogite belt. They propose that Devonian to
Carboniferous north-directed thrusting resulted from southdirected subduction, and was followed by Permian dextral
wrenching.
Bo Wang and co-authors (this volume) use LA-ICPMS
and Ar–Ar data to reveal a coincidence in time between
regional wrench faulting and granitoid emplacement in the
western Chinese Tianshan. They argue for coexistence of
diverse magmatic sources during the same tectonic episode
and suggest that post-collisional lithosphere-scale transcurrent shear zones tightly controlled the magmatic activity
during the transition from convergent margin to intraplate
anorogenic processes.
Wen Su and co-authors (this volume) examined chemically-zoned amphibole porphyroblasts from a highpressure eclogite of the western Chinese Tianshan, using an
123
electron microprobe, micro Fourier-transaform infrared
and micro-Raman spectroscopy. The data show glaucophane end-member compositions in the cores and
intermediate amphibole compositions in the rims.
Tiannan Yang and co-authors (this volume) undertook
structural and microtectonic analyses and Ar/Ar geochronology on rocks from the Turfan basin in NW China to
demonstrate that NS-directed contractional deformation
operated at ca. 266 Ma along the southern boundary of the
unified Junger-Turfan basin, and this gave rise to a NWstriking right-lateral transpressional ductile shear zone
along the SW border of the Turfan basin and to an interference pattern and thrusts in the basin interior.
Zhenhua Zhao and co-authors (this volume) review
middle Devonian magnesian andesites (MAs) that are
common in the southern Altay, as well as Carboniferous
MAs that occur in Alataoshan and West- and East-Tianshan in northern Xinjiang, NW China. They use new
petrographic, chemical and isotopic data to suggest that the
petrogenesis of the MAs in the northern Xinjiang region
may have involved multiple sources, a combination of
different petrogenetic processes, a high geothermal gradient, and unique tectonic settings including oblique
subduction, slab break off, and subduction erosion.
Qingchen Wang and co-authors (this volume) studied
the paleomagnetism and composition of detrital grains in
Cretaceous and Tertiary sandstones in the Kezilenuer-Kuqa
profile of the Chinese Tianshan and found that this part of
the Tianshan underwent two phases of differential uplift,
Int J Earth Sci (Geol Rundsch) (2009) 98:1185–1188
one in the early Cretaceous and the other from the late
Cretaceous to Tertiary.
Antoine Demoux and co-authors (this volume) report
SHRIMP zircon ages for granitoid gneisses from the Baga
Bogd massif of southern Mongolia. They recognized several episodes of zircon growth, namely (1) gneiss protolith
crystallization ages of 1,519 and 1,701 Ma, (2) granitegneiss protolith emplacement ages between 954 and
983 Ma, the first record of early Neoproterozoic magmatic
activity in the region, and (3) dioritic-granitic orthogneiss
emplacement ages between 498 and 502 Ma, which the
authors suggest represent granitoids emplaced along a
southward-growing active continental margin of the
CAOB.
Yannick Daoudene and coauthors (this volume) investigated a core complex and related Mesozoic rift basin in
the Ereendavaa Range of NE Mongolia and determined
that extension-related shearing was late Jurassic to early
Cretaceous in age, coeval with similar extension-related
core complexes in Transbaikalia and northern China, and
probably related to a single, regionally extensive tectonic
event.
Feng Guo and co-authors (this volume) examine a
135 Ma felsic volcanic suite of dacite and rhyolite from
Huolinhe in NE China that is characterized by LILE- and
light REE-enrichments, high field strength elements, Ti–P
depletion, and high radiogenic Nd, Pb and Hf isotopes.
Isotope calculations suggest that the magmas were derived
from a mixture of juvenile crust (70–80%), and 20–30% of
recycled crust with highly radiogenic Sr and Pb and unradiogenic Nd and Hf. The authors prefer a pre-Mesozoic
crustal growth model related to arc accretion associated
with Paleo-Asian ocean subduction.
Wei Liu and co-authors (this volume) use SHRIMP U-Pb
dating, laser-ablation multi-collector ICPMS Hf isotopes
and electron microprobe element analyses of inherited and
magmatic zircons from five granitoid intrusions in the
Linxi area, southern segment of the southern Altaids, to
examine continental crustal growth processes. They conclude that continental growth in this region involved a
three-step process, namely, subduction-accretion and
repeated underplating, intermediate differentiation of
juvenile rocks, and granitoid production from these differentiated rocks.
Shuan-Hong Zhang and co-authors (this volume) report
geochemical data as well as zircon ages and Nd whole-rock
isotopic systematics for early Permian calc-alkaline
granitoids along the northern margin of the North China
Craton (NCC). Previously regarded as Archean to Paleoproterozoic, they form part of a late Carboniferous to early
Permian I-type plutonic suite, emplaced along an Andeantype active continental margin during southward subduction of the Paleo-Asian oceanic plate beneath the NCC.
1187
Their data and model imply that final collision of the
Mongolian arc terranes with the NCC likely occurred in the
late Permian to earliest Triassic.
Baochun Huang and co-authors (this volume) undertook
a paleomagnetic study of Eocene-Pliocene formations in
the Kashi Depression of SW Tarim and show that the
depression behaved as a quasi-rigid block during rotation
about a vertical axis of 20° counterclockwise relative to
stable Eurasia during the late Neogene. They attribute the
rotation to two-directional thrusting by North Pamir thrusts
in the southwest and South Tianshan thrusts in the north.
Chao Yuan and co-authors (this volume) investigated a
garnet-bearing tonalitic porphyry from the eastern Kunlun
that has a SHRIMP zircon age of 213 Ma. Garnet mineralogy indicates a minimum pressure of 8–10 kbar. The rock
is enriched in LILE and LREE and depleted in Nb and Ti,
which are typical subduction-related features. Low MgO
contents of garnet and ilmenite and oxygen isotope composition of garnets suggest derivation from a MASH zone
of the lower crust. The authors suggest that early crystallization of apatite may have prevented some arc magmas
from evolving into adakitic rocks under high water
fugacity.
Jin Zhang and co-authors (this volume) studied the
structural geology of the Aixa block situated on the
northern side of the Qilian Shan. They report that the Altyn
Tagh fault does not go through the Aixa block and that a
regional conjugate fault system resulted from north-south
compression of the Qinghai-Tibetan plateau to the south in
the Miocene and Pliocene. The authors also discuss the
formation of major sedimentary basins in the region in
relation to the major conjugate fault systems.
Koen de Jong and co-authors (this volume) present
40
Ar/39Ar laser-probe pseudo-plateau ages of 218.4 ± 0.4,
228.8 ± 0.9 and 231.9 ± 0.7 Ma that date high-P/T
metamorphism of very low-grade, meta-pelitic, wholerocks in the Sakaigawa unit. They suggest that this mid-late
Triassic high-P/T metamorphic event took place in a subduction-accretion complex and was partly coeval with
proto-Japan’s collision with proto-Eurasia along the
southward extension of the Central Asian Orogenic Belt
that gave rise to the main metamorphism in the Hida-Oki
terrane.
Acknowledgments We acknowledge the reviewers of papers in this
volume for their comments, suggestions and criticism. They are, in
alphabetical order: D. Alexeiev, M. Allen, P.R. Castillo, P.A. Cawood, J. Charvet, B. Chen, W.-Ch. F.A. Dullo, G. Dupont-Nivet, J.
Gao, R. Glen, C. Johnson, K. de Jong, R. Klemd, A. Kröner, S. Lin, J.
Liou, B. Natalin, A. Polat, K. Schulmann, R. Seltmann, G. Shellnutt,
W. Siebel, E. Sobel, M. Sun, J. Whalen, S. Wilde, B.F. Windley, F.
Wu, W. Xiao, A. Yin, T. Zack, H. Zhang, and L. Zhang. We thank the
Sino-German Centre in Beijing for generous funding of the
Sino-German workshop and the Chinese State 973 Project
(2007CB411307) and the National Science Fundation for
123
1188
Distinguished Young Scholars (40725009) for financial support. This
volume is a contribution to the International Lithosphere Program
(Earth Accretionary Systems Task Force I, and Topo-Central-Asia
CC-1/4), and to IGCP Project 480.
References
de Jong K, Xiao WJ, Windley BF, Masago H, Lo C-H (2006)
Ordovician 40Ar/39Ar phengite ages from the blueschist-facies
Ondor Sum subduction-accretion complex (Inner Mongolia) and
implications for the early Palaeozoic history of continental
blocks in China and adjacent areas. Am J Sci 306:799–845
Isozaki Y, Maruyama S, Furuoka F (1990) Accreted oceanic materials
in Japan. Tectonophysics 181:179–205
Jahn B-M, Windley B, Natal’in B, Dobretsov N (2004) Phanerozoic
continental growth in Central Asia. J Asian Earth Sci 23:599–
603
Jian P, Liu DY, Kröner A, Windley BF, Shi YR, Zhang FQ, Shi GH,
Miao LC, Zhang W, Zhang Q, Zhang LQ, Ren JS (2008) Time
scale of an early to mid-Paleozoic orogenic cycle of the longlived Central Asian Orogenic Belt, Inner Mongolia of China:
implications for continental growth. Lithos 101:233–259
Kröner A, Windley BF, Badarch G, Tomurtogoo O, Hegner E, Jahn
BM, Gruschka S, Khain EV, Demoux A, Wingate MTD (2007)
Accretionary growth and crust-formation in the central Asian
Orogenic Belt and comparison with the Arabian-Nubian shield.
In: Hatcher RD Jr, Carlson MP, McBride JH, Martı́nez Catalán
JR (eds) 4-D framework of continental crust. Geological Society
of America Memoir 200, pp 181–209, doi:110.1130/2007.
1200(1111)
Maruyama S (1997) Pacific-type orogeny revisited: Miyashiro-type
orogeny proposed. Island Arc 6:91–120
123
Int J Earth Sci (Geol Rundsch) (2009) 98:1185–1188
Şengör AMC, Natal’in B (1996) Turkic-type orogeny and its role in
the making of the continental crust. Annu Rev Earth Planet Sci
24:263–337
Şengör AMC, Natal’in BA, Burtman US (1993) Evolution of the
Altaid tectonic collage and Paleozoic crustal growth in Eurasia.
Nature 364:209–304
Xiao WJ, Kröner A (2007) Conference report: Sino-German Workshop ‘‘Geodynamic Evolution of Central Asia in the Paleozoic
and Mesozoic’’, Beijing, China, December 4–9, 2006. Episodes
30:224–225
Xiao WJ, Windley BF, Hao J, Zhai MG (2003) Accretion leading to
collision and the Permian Solonker suture, Inner Mongolia,
China: termination of the Central Asian orogenic belt. Tectonics
22:1069. doi:1010.1029/2002TC1484
Xiao WJ, Zhang LC, Qin KZ, Sun S, Li JL (2004a) Paleozoic
accretionary and collisional tectonics of the Eastern Tianshan
(China): implications for the continental growth of central Asia.
Am J Sci 304:370–395
Xiao WJ, Windley BF, Badarch G, Sun S, Li JL, Qin KZ, Wang ZH
(2004b) Palaeozoic accretionary and convergent tectonics of the
southern Altaids: implications for the lateral growth of Central
Asia. J Geol Soc London 161:339–342
Xiao WJ, Pirajno F, Seltmann R (2008a) Geodynamics and metallogeny of the Altaid orogen. J Asian Earth Sci 32:77–81. doi:
10.1016/j.jseaes.2007.1010.1003
Xiao WJ, Han CM, Yuan C, Sun M, Lin SF, Chen HL, Li ZL, Li JL,
Sun S (2008b) Middle Cambrian to Permian subduction-related
accretionary orogenesis of North Xinjiang, NW China: implications for the tectonic evolution of Central Asia. J Asian Earth Sci
32:102–117. doi:110.1016/j.jseas.2007.1010.1008
Yin A, Nie S (1996) A Phanerozoic palinspastic reconstruction of
China and its neighboring regions. In: Yin A, Harrison TM (eds)
The tectonic evolution of Asia. Cambridge University Press,
Cambridge, pp 442–485