|
|
|
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
,1
,2
,3
1 Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA
2 Department of Earth and Space Sciences, University of California, Los Angeles, California 90095-1567, USA
3 Chinese Academy of Geological Sciences, Institute of Geomechanics, Beijing, 100081, China
U-Pb geochronologic analyses have been conducted on 413 detrital-zircon grains collected from 16 samples in the Altun Shan, Nan Shan, and Qilian Shan. The samples come primarily from quartz arenites and metaturbidites of Middle to Late Proterozoic age and from feldspathic and volcanic clast-rich sandstones of early Paleozoic age. Zircon grains in Proterozoic strata resting on Tarim basement yielded mainly 2.01.9 Ga ages, whereas Proterozoic strata of the Qaidam and Qilian terranes yielded mainly ca. 930820 Ma and ca. 1.91.1 Ga ages. The younger grains were apparently shed from local igneous rocks, whereas the grains older than 1.1 Ga were shed from an undetermined continental source. Grains in the lower Paleozoic strata are mainly ca. 500430 Ma and were shed from nearby plutonic and possibly volcanic rocks that formed in a magmatic arc setting.
Our detrital-zircon ages are consistent with a model (first proposed by E.R. Sobel and N. Arnaud) in which early Paleozoic magmatism occurred within a single northeast-facing magmatic arc that was constructed across an assemblage of Middle to Late Proterozoic accretionary complexes, remnants of magmatic arcs, and shallow-marine strata. This arc system was accreted to the Tarim and Sino-Korean cratons during SilurianDevonian time. The resulting suture has been reactivated as Tertiary thrust faults that currently define the structural and topographic margin of the Tibetan plateau.
Our data also provide two new estimates for the offset along the eastern Altyn Tagh fault. A belt of Middle Proterozoic shallow-marine strata is offset by
400 km, whereas a belt of 490480 Ma magmatic arc rocks is offset by
370 km. These values are generally similar to the 350400 km offset reported in most previous studies.
Key Words: tectonics continental accretion continental-margin sedimentation island arcs China
This article has been cited by other articles:
![]() |
A. Yin, Y.-Q. Dang, L.-C. Wang, W.-M. Jiang, S.-P. Zhou, X.-H. Chen, G. E. Gehrels, and M. W. McRivette Cenozoic tectonic evolution of Qaidam basin and its surrounding regions (Part 1): The southern Qilian Shan-Nan Shan thrust belt and northern Qaidam basin Geological Society of America Bulletin, July 1, 2008; 120(7-8): 813 - 846. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Yin, Y.-Q. Dang, M. Zhang, X.-H. Chen, and M. W. McRivette Cenozoic tectonic evolution of the Qaidam basin and its surrounding regions (Part 3): Structural geology, sedimentation, and regional tectonic reconstruction Geological Society of America Bulletin, July 1, 2008; 120(7-8): 847 - 876. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Zhang, C. G. Mattinson, F. Meng, Y. Wan, and K. Tung Polyphase tectonothermal history recorded in granulitized gneisses from the north Qaidam HP/UHP metamorphic terrane, western China: Evidence from zircon U-Pb geochronology Geological Society of America Bulletin, May 1, 2008; 120(5-6): 732 - 749. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. O. Lease, D. W. Burbank, G. E. Gehrels, Z. Wang, and D. Yuan Signatures of mountain building: Detrital zircon U/Pb ages from northeastern Tibet Geology, March 1, 2007; 35(3): 239 - 242. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. G. Mattinson, C. G. Mattinson, J. L. Wooden, J. G. Liou, D. K. Bird, and C. L. Wu Age and duration of eclogite-facies metamorphism, North Qaidam HP/UHP terrane, Western China Am J Sci, November 1, 2006; 306(9): 683 - 711. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. B. Rieser, Y. Liu, J. Genser, F. Neubauer, R. Handler, G. Friedl, and X.-H. Ge 40Ar/39Ar ages of detrital white mica constrain the Cenozoic development of the intracontinental Qaidam Basin, China Geological Society of America Bulletin, November 1, 2006; 118(11-12): 1522 - 1534. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Weislogel, S. A. Graham, E. Z. Chang, J. L. Wooden, G. E. Gehrels, and H. Yang Detrital zircon provenance of the Late Triassic Songpan-Ganzi complex: Sedimentary record of collision of the North and South China blocks Geology, February 1, 2006; 34(2): 97 - 100. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. J. Ryerson, P. Tapponnier, R. C. Finkel, A.-S. Meriaux, J. Van der Woerd, C. Lasserre, M.-L. Chevalier, X.-w. Xu, H.-b. Li, and G. C.P. King Applications of morphochronology to the active tectonics of Tibet Geological Society of America Special Papers, January 1, 2006; 415(0): 61 - 86. [Abstract] [Full Text] [PDF] |
||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |