@article{BougeoisDupontNivetdeRafelisetal.2018, author = {Bougeois, Laurie and Dupont-Nivet, Guillaume and de Rafelis, Marc and Tindall, Julia C. and Proust, Jean-Noel and Reichart, Gert-Jan and de Nooijer, Lennart J. and Guo, Zhaojie and Ormukov, Cholponbelk}, title = {Asian monsoons and aridification response to Paleogene sea retreat and Neogene westerly shielding indicated by seasonality in Paratethys oysters}, series = {Earth and planetary science letters}, volume = {485}, journal = {Earth and planetary science letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-821X}, doi = {10.1016/j.epsl.2017.12.036}, pages = {99 -- 110}, year = {2018}, abstract = {Asian climate patterns, characterised by highly seasonal monsoons and continentality, are thought to originate in the Eocene epoch (56 to 34 million years ago - Ma) in response to global climate, Tibetan Plateau uplift and the disappearance of the giant Proto-Paratethys sea formerly extending over Eurasia. The influence of this sea on Asian climate has hitherto not been constrained by proxy records despite being recognised as a major driver by climate models. We report here strongly seasonal records preserved in annual lamina of Eocene oysters from the Proto-Paratethys with sedimentological and numerical data showing that monsoons were not dampened by the sea and that aridification was modulated by westerly moisture sourced from the sea. Hot and arid summers despite the presence of the sea suggest a strong anticyclonic zone at Central Asian latitudes and an orographic effect from the emerging Tibetan Plateau. Westerly moisture precipitating during cold and wetter winters appear to have decreased in two steps. First in response to the late Eocene (34-37 Ma) sea retreat; second by the orogeny of the Tian Shan and Pamir ranges shielding the westerlies after 25 Ma. Paleogene sea retreat and Neogene westerly shielding thus provide two successive mechanisms forcing coeval Asian desertification and biotic crises.}, language = {en} } @article{KayaDupontNivetProustetal.2020, author = {Kaya, Mustafa Yuecel and Dupont-Nivet, Guillaume and Proust, Jean-No{\"e}l and Roperch, Pierrick and Meijer, Niels and Frieling, Joost and Fioroni, Chiara and Altiner, Sevin{\c{c}} {\"O}zkan and Stoica, Marius and Aminov, Jovid and Mamtimin, Mehmut and Guo, Zhaojie}, title = {Cretaceous evolution of the Central Asian Proto-Paratethys Sea}, series = {Tectonics}, volume = {39}, journal = {Tectonics}, number = {9}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0278-7407}, doi = {10.1029/2019TC005983}, pages = {27}, year = {2020}, abstract = {The timing and mechanisms of the Cretaceous sea incursions into Central Asia are still poorly constrained. We provide a new chronostratigraphic framework based on biostratigraphy and magnetostratigraphy together with detailed paleoenvironmental analyses of Cretaceous records of the proto-Paratethys Sea fluctuations in the Tajik and Tarim basins. The Early Cretaceous marine incursion in the western Tajik Basin was followed by major marine incursions during the Cenomanian (ca. 100 Ma) and Santonian (ca. 86 Ma) that reached far into the eastern Tajik and Tarim basins. These marine incursions were separated by a Turonian-Coniacian (ca. 92-86 Ma) regression. Basin-wide tectonic subsidence analyses imply that the Early Cretaceous sea incursion into the Tajik Basin was related to increased Pamir tectonism. We find that thrusting along the northern edge of the Pamir at ca. 130-90 Ma resulted in increased subsidence in a retro-arc basin setting. This tectonic event and coeval eustatic highstand resulted in the maximum observed geographic extent of the sea during the Cenomanian (ca. 100 Ma). The following Turonian-Coniacian (ca. 92-86 Ma) major regression, driven by eustasy, coincides with a sharp slowdown in tectonic subsidence during the late orogenic unloading period with limited thrusting. The Santonian (ca. 86 Ma) major sea incursion was likely controlled by eustasy as evidenced by the coeval fluctuations in the west Siberian Basin. An early Maastrichtian cooling (ca. 71-70 Ma), potentially connected to global Late Cretaceous trends, is inferred from the replacement of mollusk-rich limestones by bryozoan- and echinoderm-rich limestones.}, language = {en} } @article{KayaDupontNivetProustetal.2019, author = {Kaya, Mustafa Y{\"u}cel and Dupont-Nivet, Guillaume and Proust, Jean-No{\"e}l and Roperch, Pierrick and Bougeois, Laurie and Meijer, Niels and Frieling, Joost and Fioroni, Chiara and Altiner, Sevin{\c{c}} {\"O}zkan and Vardar, Ezgi and Barbolini, Natasha and Stoica, Marius and Aminov, Jovid and Mamtimin, Mehmut and Zhaojie, Guo}, title = {Paleogene evolution and demise of the proto-Paratethys Sea in Central Asia (Tarim and Tajik basins)}, series = {Basin research}, volume = {31}, journal = {Basin research}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {0950-091X}, doi = {10.1111/bre.12330}, pages = {461 -- 486}, year = {2019}, abstract = {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.}, language = {en} } @article{BlayneyDupontNivetNajmanetal.2019, author = {Blayney, Tamsin and Dupont-Nivet, Guillaume and Najman, Yani and Proust, Jean-Noel and Meijer, Niels and Roperch, Pierrick and Sobel, Edward and Millar, Ian and Guo, Zhaojie}, title = {Tectonic Evolution of the Pamir Recorded in the Western Tarim Basin (China)}, series = {Tectonics}, volume = {38}, journal = {Tectonics}, number = {2}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0278-7407}, doi = {10.1029/2018TC005146}, pages = {492 -- 515}, year = {2019}, abstract = {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.}, language = {en} }