Geomorphic Features of the Eastern Pamirs, with a Focus on the Occurrence of Intermontane Basins

Komatsu, Tsuyoshi

doi:10.1007/978-3-319-23198-3_4

Cited by 5 publications

(3 citation statements)

References 44 publications

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“…Although the main fault of this asymmetric graben runs along the western side of the valley (Komatsu, 2016), south of Karakul Lake the recent faulting activity is observed along the eastern side of the valley with vertical and left-lateral offsets of glacial deposits, small stream channels, and fluvial terraces (Strecker et al, 1995;Schurr et al, 2014;Komatsu, 2016). South of the valley, the fault enters a region of high relief in the direction of Sarez Lake.…”

Section: Tectonic Settingmentioning

confidence: 97%

Fault geometry of 2015, Mw7.2 Murghab, Tajikistan earthquake controls rupture propagation: Insights from InSAR and seismological data

Sangha

Peltzer

Zhang

et al. 2017

Earth and Planetary Science Letters

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Combining space-based geodetic and array seismology observations can provide detailed information about earthquake ruptures in remote regions. Here we use Landsat-8 imagery and ALOS-2 and Sentinel-1 radar interferometry data combined with data from the European seismology network to describe the source of the December 7, 2015, Mw7.2 Murghab (Tajikistan) earthquake. The earthquake reactivated a ∼79 km-long section of the Sarez-Karakul Fault, a NE oriented sinistral, trans-tensional fault in northern Pamir. Pixel offset data delineate the geometry of the surface break and line of sight ground shifts from two descending and three ascending interferograms constrain the fault dip and slip solution. Two right-stepping, NE-striking segments connected by a more easterly oriented segment, subvertical or steeply dipping to the west were involved. The solution shows two main patches of slip with up to 3.5 m of left lateral slip on the southern and central fault segments. The northern segment has a left-lateral and normal oblique slip of up to a meter. Back-projection of high-frequency seismic waves

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Section: Tectonic Settingmentioning

confidence: 97%

Fault geometry of 2015, Mw7.2 Murghab, Tajikistan earthquake controls rupture propagation: Insights from InSAR and seismological data

Sangha

Peltzer

Zhang

et al. 2017

Earth and Planetary Science Letters

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“…Lake Karakul (approx. 39°N and 73°25 0 E) is a closed-basin lake in the eastern Pamirs, Tajikistan, located in an active extension basin within a graben structure (Strecker et al 1995;Komatsu 2016). While the lake covers 388 km 2 at an altitude of 3915 m a.s.l., its catchment area extends over 4464 km 2 and reaches up to peaks at 6780 m a.s.l.…”

Section: Study Sitementioning

confidence: 99%

DO RADIOCARBON AGES OF PLANT WAX BIOMARKERS AGREE WITH ¹⁴C-TOC/OSL-BASED AGE MODELS IN AN ARID HIGH-ALTITUDE LAKE SYSTEM?

et al. 2021

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To elucidate the dynamics of terrestrial leaf waxes in a high-altitude lake system, we performed compound-specific radiocarbon analysis (CSRA) of long-chain n-alkanes in two sediment core sections from Lake Karakul (Pamirs, Tajikistan) and in surface soil samples from the catchment area. We aimed to answer the question whether the n-alkanes are delivered into the lake sediment with substantial delay due to storage in soils, which may cause a potential bias when used as paleoenvironmental proxies. In the surface soils, the CSRA results reveal an age range of n-alkanes from modern to 2278 ± 155 cal BP. In the two sediment core samples, three of the four n-alkane ages fell on the lower ends of the 1σ-uncertainty ranges of modeled ages of the sediments (based on AMS 14C-TOC and OSL dating results). We conclude that sedimentary leaf waxes represent compounds with intermediate turnover time in soils, for example originating from alluvial plains close to the shores. Overall, the results provide evidence that sedimentary leaf wax compounds in this cold and arid setting are potentially older than the conventional age model indicates, but these findings need to be interpreted in context of the generally large uncertainty ranges of such age models.

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“…。そしてこの結果を受けた地質学や熱年代学の研究から沈み込む大陸リソスフェアの影響を組み入れた新生代の地質構造発達史が提示されるようになった (Sobel et al, 2013;Thiede et al, 2013;Stearns et al, 2015) 。同時に測地データ (Mohadjer et al, 2010;Zubovich et al, 2010;Ischuk et al, 2013) 断層・褶曲運動に関するデータ(例えば, Fu et al, 2010;Chevalier et al, 2011;Li et al, 2012;Chevalier et al, 2015;Robinson et al, 2015) 100 万年スケールから 1,000 ～ 10,000 年スケールでの削剥速度に関するデータ(例えば, Seong et al, 2009a;Carrapa et al, 2014;Fuchs et al, 2015) Brookfield, 2008;Schmidt et al, 2011;Mechie et al, 2012;Robinson et al, 2012;Burtman, 2013;Schurr et al, 2014) (Aizen et al, 2009) 。こうした背景からパミール内の年平均降水量はパミール西部の北西山地でもっとも多く 700 ～ 1100 mm/a に達する (Komatsu, 2016 (例えば, Strecker et al, 2003;…”

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Cenozoic Tectonic Evolution of the Pamir: A Review

Komatsu

2016

Journal of Geography(Chigaku Zasshi)

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The Pamir is a mountain region in the westernmost part of the Himalayan-Tibetan orogen. It extends ～300 km from north to south and ～300-400 km from west to east. The Pamir lies on a double subduction zone, where two buoyant continental plates have subducted several hundred kilometers deep into the asthenosphere. The southern plate is the northward-dipping Hindu Kush slab, and the northern plate is the southward-dipping Pamir slab. The subduction of the Hindu Kush slab began at ～8 Ma. This narrow part of the Indian plate subducts to a depth of ～600 km and has a neck at a depth of between 250 and 300 km, causing lithospheric thinning. The Pamir slab, a part of the Asian plate, probably started subduction at ～25 Ma accompanied by slab rollback (possibly with the back-arc extension) , subduction erosion, subduction accretion, and marginal slab-tear faulting. This slab, subducting to depths of ～400-450 km, forms a broad arcuate shape split at the center due to a vertical tear extending from a depth of ～200 to ～400 km. The current geometry of both slabs implies the possible occurrence of tectonic events, such as slab break-off, in the near geological future. The metamorphic and exhumation history of the crystalline basement domes in the Pamir reveal regional tectonic evolution since the Cenozoic India-Asia collision. Prograde metamorphism of the mid-lower crust, driven by crustal shortening/ thickening, continued from 45 to 25 Ma. Subsequently, retrograde metamorphism and exhumation of the mid-lower crust began during the period 25-15 Ma. This change suggests a transition from crustal shortening/thickening to crustal extension. A possible cause of this transition is that the Pamir slab obtained sufficient gravitational potential to enable the gravitational collapse of the crust, mainly due to the isostatic uplift of the orogen, which was triggered by the break-off of the Indian plate during 25-15 Ma. Subsequently, activation of extensional exhumation in the southwest and eastern Pamir was synchronous with magmatism in the eastern Pamir at ～10 Ma. At present, the Pamir region is characterized by an active E-W extension of the Kongur Shan footwall to the east and a westward lateral extension of the western Pamir into the Tajik-Afghan Basin.

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Geomorphic Features of the Eastern Pamirs, with a Focus on the Occurrence of Intermontane Basins

Cited by 5 publications

References 44 publications

Fault geometry of 2015, Mw7.2 Murghab, Tajikistan earthquake controls rupture propagation: Insights from InSAR and seismological data

Fault geometry of 2015, Mw7.2 Murghab, Tajikistan earthquake controls rupture propagation: Insights from InSAR and seismological data

DO RADIOCARBON AGES OF PLANT WAX BIOMARKERS AGREE WITH ¹⁴C-TOC/OSL-BASED AGE MODELS IN AN ARID HIGH-ALTITUDE LAKE SYSTEM?

Cenozoic Tectonic Evolution of the Pamir: A Review

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Geomorphic Features of the Eastern Pamirs, with a Focus on the Occurrence of Intermontane Basins

Cited by 5 publications

References 44 publications

Fault geometry of 2015, Mw7.2 Murghab, Tajikistan earthquake controls rupture propagation: Insights from InSAR and seismological data

Fault geometry of 2015, Mw7.2 Murghab, Tajikistan earthquake controls rupture propagation: Insights from InSAR and seismological data

DO RADIOCARBON AGES OF PLANT WAX BIOMARKERS AGREE WITH 14C-TOC/OSL-BASED AGE MODELS IN AN ARID HIGH-ALTITUDE LAKE SYSTEM?

Cenozoic Tectonic Evolution of the Pamir: A Review

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DO RADIOCARBON AGES OF PLANT WAX BIOMARKERS AGREE WITH ¹⁴C-TOC/OSL-BASED AGE MODELS IN AN ARID HIGH-ALTITUDE LAKE SYSTEM?