TY - JOUR A1 - Kaya, Mustafa Yücel A1 - Dupont-Nivet, Guillaume A1 - Proust, Jean‐Noël A1 - Roperch, Pierrick A1 - Bougeois, Laurie A1 - Meijer, Niels A1 - Frieling, Joost A1 - Fioroni, Chiara A1 - Altiner, Sevinç Özkan A1 - Vardar, Ezgi A1 - Barbolini, Natasha A1 - Stoica, Marius A1 - Aminov, Jovid A1 - Mamtimin, Mehmut A1 - Zhaojie, Guo T1 - Paleogene evolution and demise of the proto-Paratethys Sea in Central Asia (Tarim and Tajik basins) BT - Role of intensified tectonic activity at ca. 41 Ma JF - Basin research N2 - The proto-Paratethys Sea covered a vast area extending from the Mediterranean Tethys to the Tarim Basin in western China during Cretaceous and early Paleogene. Climate modelling and proxy studies suggest that Asian aridification has been governed by westerly moisture modulated by fluctuations of the proto-Paratethys Sea. Transgressive and regressive episodes of the proto-Paratethys Sea have been previously recognized but their timing, extent and depositional environments remain poorly constrained. This hampers understanding of their driving mechanisms (tectonic and/or eustatic) and their contribution to Asian aridification. Here, we present a new chronostratigraphic framework based on biostratigraphy and magnetostratigraphy as well as a detailed palaeoenvironmental analysis for the Paleogene proto-Paratethys Sea incursions in the Tajik and Tarim basins. This enables us to identify the major drivers of marine fluctuations and their potential consequences on Asian aridification. A major regional restriction event, marked by the exceptionally thick (<= 400 m) shelf evaporites is assigned a Danian-Selandian age (ca. 63-59 Ma) in the Aertashi Formation. This is followed by the largest recorded proto-Paratethys Sea incursion with a transgression estimated as early Thanetian (ca. 59-57 Ma) and a regression within the Ypresian (ca. 53-52 Ma), both within the Qimugen Formation. The transgression of the next incursion in the Kalatar and Wulagen formations is now constrained as early Lutetian (ca. 47-46 Ma), whereas its regression in the Bashibulake Formation is constrained as late Lutetian (ca. 41 Ma) and is associated with a drastic increase in both tectonic subsidence and basin infilling. The age of the final and least pronounced sea incursion restricted to the westernmost margin of the Tarim Basin is assigned as Bartonian-Priabonian (ca. 39.7-36.7 Ma). We interpret the long-term westward retreat of the proto-Paratethys Sea starting at ca. 41 Ma to be associated with far-field tectonic effects of the Indo-Asia collision and Pamir/Tibetan plateau uplift. Short-term eustatic sea level transgressions are superimposed on this long-term regression and seem coeval with the transgression events in the other northern Peri-Tethyan sedimentary provinces for the 1st and 2nd sea incursions. However, the 3rd sea incursion is interpreted as related to tectonism. The transgressive and regressive intervals of the proto-Paratethys Sea correlate well with the reported humid and arid phases, respectively in the Qaidam and Xining basins, thus demonstrating the role of the proto-Paratethys Sea as an important moisture source for the Asian interior and its regression as a contributor to Asian aridification. KW - aridification KW - Asia KW - biostratigraphy KW - climate KW - magnetostratigraphy KW - microfossil KW - Paleogene KW - Pamir KW - proto-Paratethys KW - regression KW - Tajik Basin KW - Tarim Basin KW - tectonism KW - westerlies Y1 - 2018 U6 - https://doi.org/10.1111/bre.12330 SN - 0950-091X SN - 1365-2117 VL - 31 IS - 3 SP - 461 EP - 486 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Blayney, Tamsin A1 - Dupont-Nivet, Guillaume A1 - Najman, Yani A1 - Proust, Jean-Noel A1 - Meijer, Niels A1 - Roperch, Pierrick A1 - Sobel, Edward A1 - Millar, Ian A1 - Guo, Zhaojie T1 - Tectonic Evolution of the Pamir Recorded in the Western Tarim Basin (China) BT - Sedimentologic and Magnetostratigraphic Analyses of the Aertashi Section JF - Tectonics N2 - The northward indentation of the Pamir salient into the Tarim basin at the western syntaxis of the India-Asia collision zone is the focus of controversial models linking lithospheric to surface and atmospheric processes. Here we report on tectonic events recorded in the most complete and best-dated sedimentary sequences from the western Tarim basin flanking the eastern Pamir (the Aertashi section), based on sedimentologic, provenance, and magnetostratigraphic analyses. Increased tectonic subsidence and a shift from marine to continental fluvio-deltaic deposition at 41Ma indicate that far-field deformation from the south started to affect the Tarim region. A sediment accumulation hiatus from 24.3 to 21.6Ma followed by deposition of proximal conglomerates is linked to fault propagation into the Tarim basin. From 21.6 to 15.0Ma, increasing accumulation rates of fining upward clastics is interpreted as the expression of a major dextral transtensional system linking the Kunlun to the Tian Shan ahead of the northward Pamir indentation. At 15.0Ma, the appearance of North Pamir-sourced conglomerates followed at 11Ma by Central Pamir-sourced volcanics coincides with a shift to E-W compression, clockwise vertical-axis rotations and the onset of growth strata associated with the activation of the local east vergent Qimugen thrust wedge. Together, this enables us to interpret that Pamir indentation into Tarim had started by 24.3Ma, reached the study location by 15.0Ma and had passed it by 11Ma, providing kinematic constraints on proposed tectonic models involving intracontinental subduction and delamination. KW - India-Asia collision KW - Tarim basin KW - Pamir KW - Cenozoic KW - paleomagnetism KW - sedimentology Y1 - 2019 U6 - https://doi.org/10.1029/2018TC005146 SN - 0278-7407 SN - 1944-9194 VL - 38 IS - 2 SP - 492 EP - 515 PB - American Geophysical Union CY - Washington ER -