TY - JOUR A1 - Zhou, Renjie A1 - Schoenbohm, Lindsay M. A1 - Sobel, Edward A1 - Carrapa, Barbara A1 - Davis, Donald W. T1 - Sedimentary record of regional deformation and dynamics of the thick-skinned southern Puna Plateau, central Andes (26-27 degrees S) JF - Earth & planetary science letters N2 - The Puna Plateau, adjacent Eastern Cordillera and the Sierras Pampeanas of the central Andes are largely characterized by thick-skinned, basement-involved deformation. The Puna Plateau hosts similar to N-S trending bedrock ranges bounded by deep-seated reverse faults and sedimentary basins. We contribute to the understanding of thick-skinned dynamics in the Puna Plateau by constraining regional kinematics of the poorly understood southern Puna Plateau through a multidisciplinary approach. On the southeastern plateau, sandstone modal composition and detrital zircon U-Pb and apatite fission-track data from Cenozoic strata indicate basin accumulation during the late Eocene to early Oligocene (similar to 38-28 Ma). Provenance analysis reveals the existence of a regional-scale basin covering the southern Puna Plateau during late Eocene to early Oligocene time (similar to 38-28 Ma) that was sourced from both the western plateau and the eastern plateau margin and had a depocenter located to the west. Petrographic and detrital zircon U-Pb data reveal erosion of proximal western and eastern sources after 12 Ma, in mid-late Miocene time. This indicates that the regional basin was compartmentalized into small-scale depocenters by the growth of basement-cored ranges continuing into the late Miocene (similar to 12-8 Ma). We suggest that the Cenozoic history of the southern Puna Plateau records the formation of a regional basin that was possibly driven by lithospheric flexure during the late Eocene to early Oligocene, before the growth of distributed basement-cored ranges starting as early as the late Oligocene. (C) 2015 Elsevier B.V. All rights reserved. KW - Puna Plateau KW - regional deformation KW - basin analysis KW - thick-skinned deformation KW - zircon U-Pb geochronology KW - apatite fission-track thermochronology Y1 - 2016 U6 - https://doi.org/10.1016/j.epsl.2015.11.012 SN - 0012-821X SN - 1385-013X VL - 433 SP - 317 EP - 325 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Macaulay, Euan A. A1 - Sobel, Edward A1 - Mikolaichuk, Alexander A1 - Wack, Michael A1 - Gilder, Stuart A. A1 - Mulch, Andreas A1 - Fortuna, Alla B. A1 - Hynek, Scott A1 - Apayarov, Farid T1 - The sedimentary record of the Issyk Kul basin, Kyrgyzstan: climatic and tectonic inferences JF - Basin research N2 - A broad array of new provenance and stable isotope data are presented from two magnetostratigraphically dated sections in the south-eastern Issyk Kul basin of the Central Kyrgyz Tien Shan. The results presented here are discussed and interpreted for two plausible magnetostratigraphic age models. A combination of zircon U-Pb provenance, paleocurrent and conglomerate clast count analyses is used to determine sediment provenance. This analysis reveals that the first coarse-grained, syntectonic sediments (Dzhety Oguz formation) were sourced from the nearby Terskey Range, supporting previous thermochronology-based estimates of a ca. 25-20 Ma onset of deformation in the range. Climate variations are inferred using carbonate stable isotope (delta O-18 and delta C-13) data from 53 samples collected in the two sections and are compared with the oxygen isotope compositions of modern water from 128 samples. Two key features are identified in the stable isotope data set derived from the sediments: (1) isotope values, in particular delta C-13, decrease between ca. 26.0 and 23.6 or 25.6 and 21.0 Ma, and (2) the scatter of delta O-18 values increased significantly after ca. 22.6 or 16.9 Ma. The first feature is interpreted to reflect progressively wetter conditions. Because this feature slightly post-dates the onset of deformation in the Terskey Range, we suggest that it has been caused by orographically enhanced precipitation, implying that surface uplift accompanied late Cenozoic deformation and rock uplift in the Terskey Range. The increased scatter could reflect variable moisture source or availability caused by global climate change following the onset of Miocene glaciations at ca. 22.6 Ma, or enhanced evaporation during the Mid-Miocene climatic optimum at ca. 17-15 Ma. Y1 - 2016 U6 - https://doi.org/10.1111/bre.12098 SN - 0950-091X SN - 1365-2117 VL - 28 SP - 57 EP - 80 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Blayney, Tamsin A1 - Najman, Yani A1 - Dupont-Nivet, Guillaume A1 - Carter, Andrew A1 - Millar, Ian A1 - Garzanti, Eduardo A1 - Sobel, Edward A1 - Rittner, Martin A1 - Ando, Sergio A1 - Guo, Zhaojie A1 - Vezzoli, Giovanni T1 - Indentation of the Pamirs with respect to the northern margin of Tibet: Constraints from the Tarim basin sedimentary record JF - Tectonics N2 - The Pamirs represent the indented westward continuation of the northern margin of the Tibetan Plateau, dividing the Tarim and Tajik basins. Their evolution may be a key factor influencing aridification of the Asian interior, yet the tectonics of the Pamir Salient are poorly understood. We present a provenance study of the Aertashi section, a Paleogene to late Neogene clastic succession deposited in the Tarim basin to the north of the NW margin of Tibet (the West Kunlun) and to the east of the Pamirs. Our detrital zircon U-Pb ages coupled with zircon fission track, bulk rock Sm-Nd, and petrography data document changes in contributing source terranes during the Oligocene to Miocene, which can be correlated to regional tectonics. We propose a model for the evolution of the Pamir and West Kunlun (WKL), in which the WKL formed topography since at least similar to 200 Ma. By similar to 25 Ma, movement along the Pamir-bounding faults such as the Kashgar-Yecheng Transfer System had commenced, marking the onset of Pamir indentation into the Tarim-Tajik basin. This is coincident with basinward expansion of the northern WKL margin, which changed the palaeodrainage pattern within the Kunlun, progressively cutting off the more southerly WKL sources from the Tarim basin. An abrupt change in the provenance and facies of sediments at Aertashi has a maximum age of 14 Ma; this change records when the Pamir indenter had propagated sufficiently far north that the North Pamir was now located proximal to the Aertashi region. Y1 - 2016 U6 - https://doi.org/10.1002/2016TC004222 SN - 0278-7407 SN - 1944-9194 VL - 35 SP - 2345 EP - 2369 PB - American Geophysical Union CY - Washington ER -