Late Miocene deformation and surface uplift of the North Pamir

<p>The Pamir Plateau, as the west extension of the Tibetan Plateau, forms a prominent salient into central Asia. Previous studies have suggested that the Pamir indented northward, causing retreat of the proto-Paratethys Sea and aridification of Central Asia. However, its indentation and surface uplift history are poorly constrained, with existing studies focusing mainly on the eastern side of the Pamir salient. This study presents new multi-proxy data from the southeast Tajik Basin, located on the western side of the salient, to explore the tectonic evolution of the Pamir Plateau. In the southeast Tajik Basin, our magnetostratigraphic study indicates that the fluvial and alluvial strata were deposited between ~20-8 Ma, with thick conglomerates starting at ~15 Ma. Provenance data from sandstone detrital zircon U-Pb ages and mudstone eNd values indicate a pronounced shift in sediment source from the Central Pamir to the North Pamir around 12 Ma. This provenance change is corroborated by carbonate stable oxygen isotopes showing a gradual decreasing trend between 12-8 Ma, which most likely reflects surface uplift of the North Pamir. Collectively, our results indicate that the North Pamir was originally part of the broad Tarim-Tajik Basin, and has been gradually uplifted since ~12 Ma.</p>

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Middle–Late Triassic sedimentary provenance of the southern Junggar Basin and its link with the post-orogenic tectonic evolution of Central Asia

Scientific Reports ◽

10.1038/s41598-021-96455-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jialin Wang ◽

Chaodong Wu ◽

Yue Jiao ◽

Bo Yuan

Keyword(s):

Central Asia ◽

Detrital Zircon ◽

Tectonic Evolution ◽

Sedimentary Rocks ◽

Junggar Basin ◽

Upper Triassic ◽

Late Triassic ◽

The North ◽

Sedimentary Provenance ◽

Source To Sink

AbstractDue to the unknown Triassic volcanism in the Junggar Basin, the Middle–Late Triassic sedimentary provenance in the southern Junggar Basin (SJB) has long been controversial. Detrital zircon grains from 13 samples of the Middle–Upper Triassic Xiaoquangou Group in the SJB were analyzed using zircon U–Pb geochronology to constrain the provenance of Triassic sedimentary rocks and to further understand their source-to-sink system. Comparison of detrital zircon U–Pb age distributions for 13 samples reveals that the Triassic age populations predominate in sediments of the northern Bogda Mountains, with subordinate in the southern Bogda Mountains, and no or minimal in the North Tianshan (NTS). Coupled with sandstone petrological, sedimentary geochemical and paleocurrent data, the Triassic detrital zircon grains of the Xiaoquangou Group in the SJB were probably input from the Bogda Mountains. As Pennsylvanian and Mississippian zircon grains are mainly derived from the NTS and Central Tianshan (CTS), the provenance of the Xiaoquangou Group includes the NTS, CTS and Bogda Mountains. But the different samples in different sink areas have different provenances, originating from at least four source-to-sink systems. The supply of sediments from the Bogda Mountains started in the Late Triassic, suggesting initial uplift of the Bogda Mountains.

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Evolution of Orogenic Plateaus at Subduction Zones - Sinking and raising the southern margin of the Central Anatolian Plateau

10.31237/osf.io/hf759 ◽

2018 ◽

Author(s):

David Fernández-Blanco

Keyword(s):

Tectonic Evolution ◽

Subduction Zones ◽

Inversion Tectonics ◽

High Discharge ◽

Anatolian Plateau ◽

Surface Uplift ◽

Southern Margin ◽

Wide Range ◽

Forearc Basins ◽

Orogenic Plateaus

Orogenic plateaus have raised abundant attention amongst geoscientists during the last decades, offering unique opportunities to better understand the relationships between tectonics and climate, and their expression on the Earth’s surface.Orogenic plateau margins are key areas for understanding the mechanisms behind plateau (de)formation. Plateau margins are transitional areas between domains with contrasting relief and characteristics; the roughly flat elevated plateau interior, often with internally drained endorheic basins, and the external steep areas, deeply incised by high-discharge rivers. This thesis uses a wide range of structural and tectonic approaches to investigate the evolution of the southern margin of the Central Anatolian Plateau (CAP), studying an area between the plateau interior and the Cyprus arc. Several findings are presented here that constrain the evolution, timing and possible causes behind the development of this area, and thus that of the CAP. After peneplanation of the regional orogeny, abroad regional subsidence took place in Miocene times in the absence of major extensional faults, which led to the formation of a large basin in the northeast Mediterranean. Late Tortonian and younger contractional structures developed in the interior of the plateau, in its margin and offshore, and forced the inversion tectonics that fragmented the early Miocene basin into the different present-day domains. The tectonic evolution of the southern margin of the CAP can be explained based on the initiation of subduction in south Cyprus and subsequent thermo-mechanical behavior of this subduction zone and the evolving rheology of the Anatolian plate. The Cyprus slab retreat and posterior pull drove subsidence first by relatively minor stretching of the crust and then by its flexure. The growth by accretion and thickening of the upper plate, and that of the associated forearc basins system, caused by accreting sediments, led to rheological changes at the base of the crust that allowed thermal weakening, viscous deformation, driving subsequent surface uplift and raising the modern Taurus Mountains. This mechanism could be responsible for the uplifted plateau-like areas seen in other accretionary margins. ISBN: 978-90-9028673-0

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OREL SECURITY OFFICER BORIS GORDON AND THE «RED CHAPEL»

Journal of Public and Municipal Administration ◽

10.22394/2225-8272-2020-9-3-164-175 ◽

2020 ◽

Vol 9 (3) ◽

pp. 164-175

Author(s):

A.Yu. SARAN ◽

◽

M.V. SOKOLOV ◽

Keyword(s):

Central Asia ◽

Nazi Germany ◽

Career Ladder ◽

Security Officer ◽

State Security ◽

Successful Career ◽

The North ◽

South Central ◽

Foreign Countries ◽

Party Work

The purpose of the article is to study the biography of B.M. Gordon as a successful security officer in the 1920-s and 1930-s. He worked his way up the career ladder from a junior investigator to the head of regional divisions – territorial bodies of the VChK/GPU/OGPU/NKVD and the legal residency of the INO GUGB of NKVD in Germany. Having started his chekist service in the Orel province, he served in the South – Central Asia, in the North – in Arkhangelsk province,in the capital of the USSR, and in the capital of Nazi Germany – Berlin. Gordon fought with the white guards and evicted the dispossessed peasants, controlled the Soviet military and gathered information about the armies of foreign countries; he managed to work at both Soviet and party work. Finally, the energetic work and successful career led Boris Moiseyevich Gordon to his death, when in 1937, J.V. Stalin decided to destroy completely all the former operational leadership of the state security agencies, replacing it with new personnel.

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