Abstract The geological evolution of Central Asia commenced with the evolution of a complex Precambrian–Palaeozoic orogen. Cimmerian blocks were then accreted to the southern margin during the Mesozoic, leading to tectonic reactivation of older structures and discrete episodes of basin formation. The Indian and Arabian blocks collided with Asia during the Cenozoic, leading to renewed structural reactivation, intracontinental deformation and basin development. This complex evolution resulted in the present-day setting of an elongated Tien Shan range flanked by large Mesozoic–Cenozoic sedimentary basins with smaller intramontane basins distributed within the range. The aim of this volume is to present multidisciplinary results and reviews from research groups in Europe and Central Asia that focus on the western part of the Tien Shan and some of the large sedimentary basins in that area. These works elucidate the Late Palaeozoic–Cenozoic tectono-sedimentary evolution of the area. Emphasis is placed on the collision of terranes and/or continents and the ensuing fault reactivation; the impact of changes in climate on the sedimentation is also examined. Gold Open Access: This article is published under the terms of the CC-BY 3.0 license .

Abstract Regional strike-slip faults are widely distributed in continental interiors and play a major role in the distribution of far-field deformation due to continental collisions. Constraining the deformation history of the Talas–Fergana Fault (TFF), one of the largest of such faults in the Himalayan deformed interior, is vital to comprehend the hinterland kinematics of the India–Asia collision. New apatite fission track results from the NW Tien Shan define a rapid exhumation event at c . 25 Ma. This event is correlated with a synchronous pulse in the South Tien Shan, implying that both ranges experienced a simultaneous onset of rapid exhumation. We suggest that strike-slip motion along the TFF commenced at c . 25 Ma, facilitating counter-clockwise rotation of the Fergana Basin and enabling exhumation of the linked horsetail splays. Pamir indentation, located south of the Western Tien Shan, is postulated to be underway by c . 20 Ma. Recently published results suggest synchronous strike-slip deformation in the western Tarim Basin and eastern flank of the Pamir. Based on our results and published data, we are able to connect Tarim and Pamir deformation to the onset of TFF slip. We suggest that this pre-existing regional structure was responsible for transferring Pamir-induced shortening to the NW Tien Shan. Supplementary material: Supplementary material is available at http://www.geolsoc.org.uk/SUP18845

Abstract The least well-documented intramountain basin within the Tien Shan is the Fergana Basin. Cenozoic deformation is localized along thrusts on the northern and southern flanks, and by transpressive deformation associated with the dextral Talas–Fergana Fault on the eastern margin. We use sedimentological and stratigraphic observations from well-exposed Cenozoic outcrops to describe depositional environments, provenance and sources. These results are combined with interpreted seismic reflection lines and geological cross-sections are extended laterally based on outcrop geology to the north and east. Following a tectonically quiet early Cenozoic period, a progressive change in palaeocurrent indicators suggests Oligo-Miocene uplift of the hinterland, coupled with an increase in higher energy facies in the Massaget Formation. A renewed pulse of deformation tilted Massaget strata and deposited a considerable volume of coarse sedimentary rocks (Baktriy Formation). The younger episode moved progressively basinwards, as imaged by growth–strata relationships in the subsurface. Published work shows that the accumulation of an impressive c . 8 km of Cenozoic deposits cannot be accommodated only by lithospheric flexure produced by a tectonic load. We agree with the hypothesis that the thick sediments preserved in the basin are accommodated by lithospheric folding and propose that this is driven by compression associated with south-vergent Pamir subduction.

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