Pleistocene glaciations of Central Asia: results from 10Be surface exposure ages of erratic boulders from the Pamir (Tajikistan), and the Alay–Turkestan range (Kyrgyzstan)

Abramowski, Uwe; Bergau, Arne; Seebach, Dominik; Zech, Roland; Glaser, Bruno; Sosin, Piotr; Kubik, Peter W.; Zech, Wolfgang

doi:10.1016/j.quascirev.2005.10.003

Cited by 118 publications

(122 citation statements)

References 51 publications

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“…Glacial advances particularly during the Late Quaternary likely affected the drainage evolution by changing transported sediment volumes and river discharge and therefore may have triggered the development of river terraces along the Panj. Information regarding the Quaternary glacial chronology of the Pamir is limited to few study sites on the Pamir Plateau (Zech et al, 2005a;Abramowski et al, 2006;Röhringer et al, 2012). A chronology for local glacial landforms at lower altitudes in west-trending valleys has yet to be established.…”

Section: Present and Past Climatic Conditionsmentioning

confidence: 99%

Rates of river incision across the main tectonic units of the Pamir identified using optically stimulated luminescence dating of fluvial terraces

et al. 2014

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Calculated incision rates along the Panj, the main river of the Pamir, are used to investigate any influence by tectonics or climate on the architecture of the river. The depositional ages of Panj river terraces were calculated using optically stimulated luminescence (OSL) dating of terrace sand. Fluvial incision rates were generated by integrating the terrace depositional ages with accurate kinematic GPS measurements of terrace heights above the modern Panj. We investigated 16 terraces along the Panj at the western Pamir margin and one terrace from the Vakhsh River to the north of the Pamir. The results reveal brief periods of fluvial deposition over the past 26 kyr. The oldest Panj terrace depositional ages coincide with early MIS 2 and MIS 2/1 glaciations on the Pamir Plateau. Younger terrace ages have no apparent link with glacial cycles. Terraces with varying heights above the modern Panj at different localities yielded similar depositional ages. This suggests that local conditions have determined fluvial incision rates. Combining all of the terrace measurements, the average incision rate of the Panj over the last 26 kyr has been ∼5.6 mm/yr. A high mean incision rate of ∼7.3 mm/yr was calculated from terraces where the Panj has cut a steep-sided valley through the Shakhdara Dome. Significantly lower incision rates (∼2 -3 mm/yr) were calculated from terraces where the Panj flows along the southern boundaries of the Shakhdara and Yazgulom domes. At those localities, graded segments of the Panj river profile and increased valley widths are indicative of local base levels. Downstream of the Yazgulom Dome, river incision rates are generally lower (∼4 -5 mm/yr) than the Panj average. However, there is one exception where higher incision rates (∼6 mm/yr) were calculated upstream of the Darvaz Fault Zone, a major tectonic feature that forms the western boundary of the Pamir. The Vakhsh river terrace to the north of the Pamir yielded a lower incision rate (∼3 mm/yr) compared to the Panj average. Variation in incision rates along the Panj does not correspond to changes in rock type or river catchment area. Instead, incision rates appear to have been primarily influenced by river capture across the southern and central metamorphic domes of the Pamir. Wherever the Panj cuts these domes it displays a convex river profile. The combination of localized river profile convexity and changes in incision rates across the Pamir domes indicates that the dome boundaries have been active recently.

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Section: Present and Past Climatic Conditionsmentioning

confidence: 99%

Rates of river incision across the main tectonic units of the Pamir identified using optically stimulated luminescence dating of fluvial terraces

et al. 2014

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“…Defining the ages of landforms and sediments throughout much of the HimalayanTibetan orogen has been particularly difficult because of the Shiraiwa, 1993;Sharma and Owen, 1996;Phillips et al, 2000;Richards et al, 2000a,b;Owen et al, 2001Owen et al, , 2002aOwen et al, ,b, 2003aOwen et al, ,b,c, 2005Owen et al, , 2006aSchäfer et al, 2002;Tsukamoto et al, 2002;Yi et al, 2002;Finkel et al, 2003;Zech et al, 2003Zech et al, , 2005Barnard et al, 2004aBarnard et al, ,b, 2006aMeriaux et al, 2004;Spencer and Owen, 2004;Chevalier et al, 2005;Abramowski et al, 2006;Colgan et al, 2006;Seong et al, 2007Seong et al, , 2008a. The red dots in part (A) highlight regions where TCN surface exposure dating has been undertaken.…”

Section: Extent Of Glaciationmentioning

confidence: 99%

“…60 and 30 ka, and that glaciers advanced during the early to middle Holocene. A plethora of papers following this work emerged and they included distant regions throughout the HimalayanTibetan orogen (Owen et al, , 2002a(Owen et al, ,b, 2003a(Owen et al, ,b,c, 2005Schäfer et al, 2002;Finkel et al, 2003;Zech et al, 2003Zech et al, , 2005Barnard et al, 2004aBarnard et al, ,b, 2006aMeriaux et al, 2004;Chevalier et al, 2005;Abramowski et al, 2006;Seong et al, 2007Seong et al, , 2008a. summarised the TCN studies and suggested that the regional patterns and timing of glaciation reflect temporal and spatial variability in the South Asian monsoon and, in particular, in regional precipitation gradients.…”

Section: Timing Of Glaciationmentioning

confidence: 99%

“…The possibility of numerous glacier advances also complicates correlations between regions based on TCN dating, especially because the TCN dating method is relatively imprecise ($8% systematic error; Balco et al, 2008). A detailed interpretation of the interregional variability therefore requires more comprehensive Owen et al, 2001Owen et al, , 2002aOwen et al, ,c, 2003aOwen et al, ,b,c, 2005Owen et al, , 2006aSchäfer et al, 2002;Finkel et al, 2003;Zech et al, 2003Zech et al, , 2005Barnard et al, 2004aBarnard et al, ,b, 2006aMeriaux et al, 2004;Chevalier et al, 2005;Abramowski et al, 2006;Colgan et al, 2006;Seong et al, 2007Seong et al, , 2008a. The number of samples used to produce each probability plot is indicated by 'n' All data 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 Figure 9 Probability density functions of TCN 10 Be ages for all published data from the Himalayan-Tibetan orogen plotted for each major climatic region.…”

Section: Timing Of Glaciationmentioning

confidence: 99%

“…The number of samples used to produce each probability plot is indicated by 'n' All data 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 120 20 30 40 50 60 70 80 90 100 110 Figure 9 Probability density functions of TCN 10 Be ages for all published data from the Himalayan-Tibetan orogen plotted for each major climatic region. (A) All published data; (B) MIS 1 and MIS 2; and (C) MIS 3 to MIS 5e (data from Phillips et al, 2000;Owen et al, 2001Owen et al, , 2002aOwen et al, ,b, 2003aOwen et al, ,b,c, 2005Owen et al, , 2006aSchäfer et al, 2002;Finkel et al, 2003;Zech et al, 2003Zech et al, , 2005Barnard et al, 2004aBarnard et al, ,b, 2006aMeriaux et al, 2004;Chevalier et al, 2005;Abramowski et al, 2006;Colgan et al, 2006;Seong et al, 2007Seong et al, , 2008a. The number of samples used to produce each probability plot is indicated by 'n' in the order of the regions shown in the legend of part (A).…”

Section: Timing Of Glaciationmentioning

confidence: 99%

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Quaternary glaciation of the Himalayan–Tibetan orogen

Owen

Caffee

Finkel

et al. 2008

J Quaternary Science

205

141

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Glacial geological evidence from throughout the Himalayan-Tibetan orogen is examined to determine the timing and extent of late Quaternary glaciation in this region and its relation to similar changes on a global scale. The evidence summarised here supports the existence of expanded ice caps and extensive valley glacier systems throughout the region during the late Quaternary. However, it cannot yet be determined whether the timing of the extent of maximum glaciation was synchronous throughout the entire region or whether the response was more varied. The lack of organic material needed for radiocarbon dating has hindered past progress in glacial reconstruction; however, application of optically stimulated luminescence and terrestrial cosmogenic radionuclide methods has recently expanded the number of chronologies throughout the region. Limits to the precision and accuracy available with these methods and, more importantly, geological uncertainty imposed by processes of moraine formation and alteration both conspire to limit the time resolution on which correlations can be made to Milankovitch timescales (several ka). In order to put all studies on a common scale, well-dated sites have been re-evaluated and all the published terrestrial cosmogenic nuclide ages for moraine boulders and glacially eroded surfaces in the Himalayan-Tibetan orogen have been recalculated. Locally detailed studies indicate that there are considerable variations in the extent of glaciation from one region to the next during a glaciation. Glaciers throughout monsoon-influenced Tibet, the Himalaya and the Transhimalaya are likely synchronous both with climate change resulting from oscillations in the South Asian monsoon and with Northern Hemisphere cooling cycles. In contrast, glaciers in Pamir in the far western regions of the Himalayan-Tibet orogen advanced asynchronously relative to the other regions that are monsooninfluenced regions and appear to be mainly in phase with the Northern Hemisphere cooling cycles. Broad patterns of local and regional variability based on equilibrium-line altitudes have yet to be fully assessed, but have the potential to help define changes in climatic gradients over time.

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Cenozoic intracontinental deformation and exhumation at the northwestern tip of the India-Asia collision-southwestern Tian Shan, Tajikistan, and Kyrgyzstan

et al. 2016

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Along the Ghissar-Alai Range of the southwestern Tian Shan (southwestern Kyrgyzstan, northern Tajikistan), the deformation front of the India-Asia collision-the Pamir-Tibet orogen-is interacting with the intracontinental Tian Shan orogen without the intervening Tarim Craton. Apatite fission track (n = 33,~3.3-145.6 Ma, 27% <10 Ma) and (U-Th)/He (n = 32,~1.9-26.1 Ma, 56% <10 Ma) thermochronologic ages suggest approximate isothermal holding (very slow cooling to weak reheating) during relative tectonic quiescence between~150 and 15 Ma. Accelerated exhumation (~0.2-1.0 km/Myr, median~0.5 km/Myr) and cooling (11-16°C/Myr) occurred over the last~10 Myr. Geomorphologic parameters-incision, river steepness, and concavity-confirm the youth of the southwestern Tian Shan's mountain building. High exhumation/cooling rates are correlated with pronounced local relief, produced by Cenozoic faults reactivating inherited (Late Paleozoic) structures. Regions with similarly young exhumation are centered along rims of rigid crustal blocks in the central and eastern Tian Shan. Structurally, the Ghissar-Alai Range is a broad, east trending zone of dextral transpression that includes the northern Tajik Basin (Illiak Fault Zone) and the Pamir Thrust System of the frontal northern Pamir. It is the particular deformation field at the northwestern tip of the India-Asia collision-the interaction of the westward gravitational collapse of the Pamir Plateau into the Tajik Basin with the bulk northward motion of the Pamir-that transformed the southwestern Tian Shan into a dextral transpression belt. The dextral transpression in the southwestern Tian Shan contrasts with sinistral strike-slip shear localized along inherited fault zones, accommodating dominant north-south shortening, in the central and eastern Tian Shan. The deformation field influenced by the Pamir and the associated young exhumation make the Ghissar-Alai Range a unique feature in the Tian Shan orogen.

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Pleistocene glaciations of Central Asia: results from 10Be surface exposure ages of erratic boulders from the Pamir (Tajikistan), and the Alay–Turkestan range (Kyrgyzstan)

Cited by 118 publications

References 51 publications

Rates of river incision across the main tectonic units of the Pamir identified using optically stimulated luminescence dating of fluvial terraces

Rates of river incision across the main tectonic units of the Pamir identified using optically stimulated luminescence dating of fluvial terraces

Quaternary glaciation of the Himalayan–Tibetan orogen

Cenozoic intracontinental deformation and exhumation at the northwestern tip of the India-Asia collision-southwestern Tian Shan, Tajikistan, and Kyrgyzstan

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