Tectonic rotations in China

Performing a fold test in the Maza Tagh
(Central Tarim)

The left lateral strike-slip Altyn Tagh Fault (ATF) extends 1500 km along the boundary between the Tibetan Plateau and the Tarim Basin. It is a key element for understanding the Indo-Asian collisional orogen and the formation of the Tibetan Plateau. Despite work carried out during the last decade in this area, the total offset, age of initiation, mechanism of formation and propagation of this fault are poorly understood. The lateral extrusion model predicts that the ATF accommodates eastward escape of the Tibetan Plateau responding to the Indo-Asian collision. In this model, large displacement (>400km) is predicted on a lithospheric scale ATF. The alternative distributed shortening model views the ATF as a transfer feature with limited displacement on a crustal scale.

The specific aim of this study was to acquire paleomagnetic data to constrain the ATF formation and motion history. Paleomagnetic sampling of Jurassic to Miocene red beds in the basins surrounding the ATF have been undertaken to constrain the deformation associated with the ATF. The major goals were to: (1) Determine the vertical-axis rotational history of intermontane Tertiary basins that are now segmented by the ATF; (2) Test the occurrence of ATF related shear in the adjacent Tula basin; (3) On a larger scale, assess the Tertiary vertical-axis rotations of the Qaidam block (South of the ATF) and the Tarim block (North of the ATF).

Publications:

Articles

• Dupont-Nivet, G.; Butler, R. F.; Yin A.; Chen, X.; in press; Paleomagnetism indicates no Neogene rotation of Qaidam Basin  during Indo-Asian Collision in Northern Tibet; Geology.

Abstracts

• Dupont-Nivet, G., Butler, R. F.,  Yin, A., Robinson, D., Zhang, Y., Qiao, W. S., 2001, Paleomagnetism of the Arka Tagh South of the Altyn Tagh Fault: Implications for Intracontinental Deformation Processes in Asia. see abstract
• Dupont-Nivet, G., Butler, R. F., Yin, A., 2000, Preliminary paleomagnetic results from Tertiary strata adjacent to the Altyn Tagh fault, EOS, Transactions, American Geophysical Union, vol. 81, No. 48, p. F 1137. see abstract
• Washburn, Z., Arrowsmith, J. R., Dupont-Nivet, G., Feng, W. X., 2000, Earthquake Geology of the Central Altyn Tagh Fault from Lake Wuzhunxiao (38.4N, 89.9E) to Lapequan (39.1N, 92.5E), China, EOS, Transactions, American Geophysical Union, vol. 81, No. 48, p. F 1137.
• Dupont-Nivet, G., Rosenberg, E., 2000, Testing distributed deformation along the Altyn Tagh Fault (ATF): Structural and paleomagnetic constraints, 28th GeoDaze Symposium, Abstracts with Programs, p. 9. see abstract

• The active tectonic aspect of the ATF project