TY - JOUR A1 - Roud, Sophie A1 - Wack, Michael Richard A1 - Gilder, Stuart A. A1 - Kudriavtseva, Anna A1 - Sobel, Edward T1 - Miocene to early pleistocene depositional history and tectonic evolution of the Issyk-Kul Basin, Central Tian Shan JF - Geochemistry, geophysics, geosystems : G 3 ; an electronic journal of the earth sciences N2 - The Issyk-Kul Basin (Kyrgyzstan), situated in the central Tian Shan Mountains, hosts the largest and deepest mountain lake in Central Asia. Erosion of the surrounding Terskey and Kungey ranges led to the accumulation of up to 4 km of sediment in the adjacent depression. Creation of the basin from regional shortening and uplift likely initiated around the Oligocene-Miocene, yet precise age control is sparse. To better understand the timing of these processes, we obtained magnetostratigraphic age constraints on fossil-poor, fluvio-lacustrine sediments exposed south of Lake Issyk-Kul, that agree well with previous age constraints of the equivalent strata outside the Issyk-Kul Basin. Two 500-650 m thick sections comprised mainly of Chu Group sediments were dated at 6.3-2.8 Ma and 7.0-2.4 Ma (late Miocene to early Pleistocene). Together with reinterpreted magnetostratigraphic constraints from underlying strata, we find that syn-tectonic deposition commenced at similar to 22 Ma with average sedimentation rates <10 cm/ka. Sedimentation rates increased to 10-30 cm/ka at 7 Ma, concurrent with accelerated uplift in the Terskey Range to the south. A deformation event in one section (Kaji-Say) between 5 and 3 Ma together with concurrent shifts of depositional centers throughout the basin signal the onset of substantial uplift of the Kungey Range to the north at similar to 5 Ma. This uplift and deformation transformed the Issyk-Kul area into a closed basin that facilitated the formation of a deep lake. Lacustrine facies deposited around 3 Ma mark the existence of Lake Issyk-Kul by that time. KW - Central Asia KW - Lake Issyk‐ Kul KW - magnetostratigraphy KW - Neogene KW - Tian KW - Shan Y1 - 2021 U6 - https://doi.org/10.1029/2020GC009556 SN - 1525-2027 VL - 22 IS - 4 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Lepetit, Petra A1 - Viereck, Lothar A1 - Piper, John D. A. A1 - Sudo, Masafumi A1 - Gurel, Ali A1 - Copuroglu, Ibrahim A1 - Gruber, Manuela A1 - Mayer, Bernhard A1 - Koch, Michael A1 - Tatar, Orhan A1 - Gursoy, Halil T1 - Ar-40/Ar-39 dating of ignimbrites and plinian air-fall layers from Cappadocia, Central Turkey: Implications to chronostratigraphic and Eastern Mediterranean palaeoenvironmental record JF - Chemie der Erde : interdisciplinary journal for chemical problems of the geo-sciences and geo-ecology N2 - Magmatism forming the Central Anatolian Volcanic Province of Cappadocia, central Turkey, records the last phase of Neotethyan subduction after similar to 11 Ma. Thirteen large calc-alkaline ignimbrite sheets form marker bands within the volcano-sedimentary succession (the Urgup Formation) and provide a robust chronostratigraphy for paleoecologic evaluation of the interleaved paleosols. This paper evaluates the chronologic record in the context of the radiometric, magnetostratigraphic and lithostratigraphic controls. Previous inconsistencies relating primarily to K/Ar evidence were reason for the initiation of an integrated study which includes Ar-40/Ar-39 dating, palaeomagnetic and stratigraphic evidence. The newly determined Ar-40/Ar-39-ages (Lepetit, 2010) are in agreement with Ar/Ar and U/Pb data meanwhile published by Pauquette and Le Pennec (2012) and Aydar et al. (2012). The Ar-40/Ar-39-ages restrict the end of the Urgup Formation to the late Miocene. The paleosol sequence enclosed by the ignimbrites is thus restricted to the late Miocene, the most intense formation of pedogene calcretes correlating with the Messinian Salinity Crisis. KW - Ar-40/Ar-39 dating KW - Tephrostratigraphy KW - Neogene KW - Cappadocia KW - Turkey Y1 - 2014 U6 - https://doi.org/10.1016/j.chemer.2014.05.001 SN - 0009-2819 SN - 1611-5864 VL - 74 IS - 3 SP - 471 EP - 488 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Hoke, Gregory D. A1 - Giambiagi, Laura B. A1 - Garzione, Carmala N. A1 - Mahoney, J. Brian A1 - Strecker, Manfred T1 - Neogene paleoelevation of intermontane basins in a narrow, compressional mountain range, southern Central Andes of Argentina JF - Earth & planetary science letters KW - Neogene KW - Andes KW - surface uplift KW - tectonics KW - paleoelevation Y1 - 2014 U6 - https://doi.org/10.1016/j.epsl.2014.08.032 SN - 0012-821X SN - 1385-013X VL - 406 SP - 153 EP - 164 PB - Elsevier CY - Amsterdam ER -