Differential uplift of the Chinese Tianshan since the Cretaceous: constraints from sedimentary petrography and apatite fission-track dating

Abstract

The Chinese Tianshan is one of the important international natural laboratories for studying continental geodynamics, but its uplift time, kinematics and mechanism of formation are key unresolved questions. In order to constrain the timing, kinematics and mechanism of uplift of the Chinese Tianshan, we applied sedimentary petrography and apatite fission-track dating to Cretaceous-Tertiary series from the northern Tarim Basin and the Tianshan Mountains. We collected and analyzed 79 sandstone samples and 75 detrital heavy mineral samples from the Kezilenuer-Kuqa profile (northern Tarim Basin) with a well-defined magnetostratigraphy. Our data indicate that detrital mineral maturity abruptly decreased at the disconformity between the Upper and Lower Cretaceous, and decreased again after 15(-12) Ma. The sediments in the northern Tarim Basin changed their provenance at 124 Ma, 26(-24) Ma and 15(-12) Ma, respectively. In addition, we collected and analyzed 36 primary apatite samples from the South, Central and North Tianshan. Our results show that the Chinese Tianshan underwent three phases of differential uplift. The first phase of uplift started at the southern Central Tianshan during the Early Cretaceous and propagated southward. The second phase of uplift started at the northern Central Tianshan during the Late Cretaceous and propagated also southward. The third phase of uplift started at the northern Central Tianshan during the Eocene and propagated both northward and southward. These differential uplifts have caused development of disconformity and drops in mineral maturity of detrital sediments in the northern Tarim Basin. Such a differential and heterogeneous uplift process might have been trigged by collisions of different microcontinents (i.e., Lhasa, Kohistan-Dras and India) at the southern margin of Asia. These collisions reactivated the South Tianshan Fault and then the North Tianshan Suture, and uplifted the Chinese Tianshan step by step.

Sedimentology and magnetostratigraphy of the Tierekesazi Cenozoic section in the foreland region of south West Tian Shan in Western China

“…Sobel et al (2013) attributed the Oligo-Miocene boundary thermochronological ages observed in the margins of southwest Tarim basin to the initial underthrusting of the Tarim block beneath the surrounding orogens, which has been testified by geophysical data in the sTS, Pamir and West Kunlun (e.g., Matte et al, 1996;Gao et al, 2000;Kao et al, 2001;Li et al, 2001;Buslov et al, 2007;Li et al, 2012;Jiang et al, 2004;Wittlinger et al, 2004;Schurr et al, 2014;Sippl et al, 2013aSippl et al, , 2013bSchneider et al, 2013). The widespread thermochronological records of this episode in West Kunlun and also sTS (Hendrix et al, 1994;Yang et al, 2003;Du and Wang, 2007;Wang and Du, 2009;Chang et al, 2012;Sobel and Dumitru, 1997;Sobel et al, 2006;Chen et al, 2008;De Grave et al, 2012;Macaulay et al, 2014) imply that the onset of underthrusting of the Tarim block during the this episode was not only limited in southwest margin of the Tarim basin, but can also take place in the south and north margins of the basin.…”

“…More recently, within the context of the IndianEurasian convergence, the Tian Shan reactivated since Oligo-Miocene boundary (Allen and Natal'in, 1995;Allen et al, 1999;Avouac and Tapponnier, 1993;Burchfiel and Royden, 1991;Burchfiel et al, 1999;Dumitru et al, 2001;Heermance et al, 2008;Jolivet et al, 2010;Lu et al, 1994;Molnar and Tapponnier, 1975;Sobel et al, 2006;Tapponnier and Molnar, 1979;Tapponnier et al, 1982;Yin et al, 1998) or earlier (Glorie et al, 2010;Jolivet et al, 2010;Wang et al, 2009;Yang et al, 2014;Zhang et al, 2014), creating terrestrial basinfills of thickness of kilometers scale in the foreland regions (e.g., Sobel and Dumitru, 1997).…”

“…Similar results were also reported by Yang et al (2003), in which the Late Paleozoic granite samples in Kuche regions of CSTS presented ages of 17-25 Ma, consistent with the cooling paths starting at ca. 25 Ma indicated by the thermal history modeling with track age and length data (Du and Wang, 2007;Wang et al, 2009). 9.…”

Diverse exhumation of the Mesozoic tectonic belt within the Yangtze Plate, China, determined by apatite fission-track thermochronology

“…It has been successfully applied to study the spatial and temporal pattern of the exhumation since the Mesozoic in Alps, Appalachia, Andes, Qinghai-Tibetan Plateau, Qingling-Dabie-Sulu etc. (e.g., Gleadow and Fitzgerald, 1987;Johnson, 1997;Gallagher et al, 1998;Willet et al, 2003;Hu et al, 2006;Richardson et al, 2008Richardson et al, , 2010Wang et al, 2009). Thus, in this study, we compile new and mostly published AFT data to better constrain the age and rate of the cooling of the Mesozoic tectonic belt (MTB) within the Yangtze Plate, provide firmer constraints on the exhumation history.…”

Exhumation of the Dahinggan Mountains, NE China from the Late Mesozoic to the Cenozoic: New evidence from fission-track thermochronology

“…2007; Tinker et al, 2008;Wang et al, 2009;Li et al, 2010;Li and Gong, in press). In this study, we use zircon and apatite FT analyses to better constrain the age and cooling rate of the Dahinggan Mountains and provide firmer constraints on their exhumation history.…”