Variations in the Iron Mineralogy of a Loess Section in Tajikistan During the Mid-Pleistocene and Late Pleistocene: Implications for the Climatic Evolution in Central Asia

2018 ◽  
Vol 19 (4) ◽  
pp. 1244-1258 ◽  
Author(s):  
Jia Jia ◽  
Hao Lu ◽  
Youjun Wang ◽  
Dunsheng Xia
Keyword(s):  
Central Asia ◽  
Late Pleistocene ◽  
Climatic Evolution ◽  
Iron Mineralogy

scholarly journals A paleomagnetic record in loess–paleosol sequences since late Pleistocene in the arid Central Asia

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Guanhua Li ◽  
Dunsheng Xia ◽  
Erwin Appel ◽  
Youjun Wang ◽  
Jia Jia ◽  
...  
Keyword(s):  
Central Asia ◽  
Late Pleistocene ◽  
Arid Central Asia

Evaluating the paleoclimatic significance of clay mineral records from a late Pleistocene loess-paleosol section of the Ili Basin, Central Asia

2017 ◽  
Vol 89 (3) ◽  
pp. 660-673 ◽  
Author(s):  
Yue Li ◽  
Yougui Song ◽  
Mengxiu Zeng ◽  
Weiwei Lin ◽  
Rustam Orozbaev ◽  
...  
Keyword(s):  
Central Asia ◽  
Clay Mineral ◽  
Late Pleistocene ◽  
Sedimentary Rocks ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Metamorphic Rocks ◽  
Paleoclimatic Reconstruction ◽  
Paleoclimatic Significance ◽  
Wind Intensity

AbstractIn this study, we present clay mineral records from a late Pleistocene loess-paleosol sequence in the Ili Basin, Central Asia, and assess their significance for paleoclimatic reconstruction. The results show that the clay minerals are mainly illite (average 60%) and chlorite (28%), with minor kaolinite (9%) and smectite (3%). Illite was of detrital origin with no obvious modification to its crystal structure. Increases in illite content in the loess are ascribed to wind intensity rather than pedogenesis. High proportions of illite in the clay fraction, and of muscovite in the bulk samples of the paleosol units, may lead to an overestimation of the weathering intensity. Kaolinite was likely inherited from the sedimentary rocks, while chlorite might have been inherited from both sedimentary and metamorphic rocks. The paleoclimatic signals of kaolinite and chlorite were unclear, due to reworking by both fluvial and eolian systems. Smectite was more likely formed by the transformation of biotite and illite, and its variation in the loess sequence was also controlled by wind intensity; this was largely due to aggregation and is unlikely to reflect moisture changes. Although the interpretation of paleoclimate evolution may contain some uncertainties, clay mineralogy does provide the possibility of tracing dust provenance.

The influence of Late Pleistocene geomorphological inheritance and Holocene hydromorphic regimes on floodwater farming in the Talgar catchment, southeast Kazakhstan, Central Asia

2015 ◽  
Vol 129 ◽  
pp. 85-95 ◽  
Author(s):  
Mark G. Macklin ◽  
Irina P. Panyushkina ◽  
Willem H.J. Toonen ◽  
Claudia Chang ◽  
Perry A. Tourtellotte ◽  
...  
Keyword(s):  
Central Asia ◽  
Late Pleistocene

Late Pleistocene glaciers in Darhad Basin, northern Mongolia

2008 ◽  
Vol 69 (2) ◽  
pp. 169-187 ◽  
Author(s):  
Alan R. Gillespie ◽  
Raymond M. Burke ◽  
Goro Komatsu ◽  
Amgalan Bayasgalan
Keyword(s):  
Central Asia ◽  
Lake Sediments ◽  
Late Pleistocene ◽  
Cosmic Ray ◽  
Luminescence Dating ◽  
Equilibrium Line ◽  
Equilibrium Line Altitude ◽  
Exposure Dating ◽  
Northern Mongolia ◽  
Dammed Lake

Late Pleistocene glaciers around Darhad Basin advanced to near their maximum positions at least three times, twice during the Zyrianka glaciation (at ∼ 17–19 ka and ∼ 35–53 ka), and at least once earlier. The Zyrianka glaciers were smaller than their predecessors, but the equilibrium-line altitude (ELA) difference was < 75 m. End moraines of the Zyrianka glaciers were ∼ 1600 m asl; ELAs were 2100–2400 m asl.14C and luminescence dating of lake sediments confirm the existence of paleolake highstands in Darhad Basin before ∼ 35 ka. Geologic evidence and10Be cosmic-ray exposure dating of drift suggests that at ∼ 17–19 ka the basin was filled at least briefly by a glacier-dammed lake ∼ 140 m deep. However, lake sediments from that time have not yet been recognized in the region. A shallower paleolake briefly occupied the basin at ∼ 11 ka, but between ∼ 11 and 17 ka and after ∼ 10 ka the basin was probably largely dry. The timing of maximum glacier advances in Darhad appears to be approximately synchronous across northern Mongolia, but different from Siberia and western Central Asia, supporting the inference that paleoclimate in Central Asia differed among regions.

scholarly journals Late Pleistocene slip rate of the Höh Serh-Tsagaan Salaa fault system, Mongolian Altai and intracontinental deformation in central Asia

2010 ◽  
Vol 183 (3) ◽  
pp. 1134-1150 ◽  
Author(s):  
Kurt L. Frankel ◽  
Karl W. Wegmann ◽  
Amgalan Bayasgalan ◽  
Robert J. Carson ◽  
Nicholas E. Bader ◽  
...  
Keyword(s):  
Central Asia ◽  
Late Pleistocene ◽  
Slip Rate ◽  
Fault System ◽  
Mongolian Altai ◽  
Intracontinental Deformation
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