TY - JOUR

T1 - Low-Temperature Thermochronology of the Chatkal-Kurama Terrane (Uzbekistan-Tajikistan)

T2 - Insights Into the Meso-Cenozoic Thermal History of the Western Tian Shan

AU - Jepson, Gilby

AU - Glorie, Stijn

AU - Konopelko, Dmitry

AU - Gillespie, Jack

AU - Danišík, Martin

AU - Mirkamalov, Rustam

AU - Mamadjanov, Yunus

AU - Collins, Alan S.

N1 - Publisher Copyright: ©2018. American Geophysical Union. All Rights Reserved.

PY - 2018/10/1

Y1 - 2018/10/1

N2 - The Chatkal-Kurama terrane represents a key region in understanding the tectonic evolution of the western Tian Shan. In this contribution, we present new thermochronological data (zircon [U-Th-Sm]/He, apatite fission track, and apatite [U-Th-Sm]/He) and the associated thermal history models for 30 igneous samples from the Chatkal-Kurama terrane within Uzbekistan and Tajikistan (west of the Talas-Fergana Fault) and integrate our data with published data from the central Tian Shan (east of the Talas-Fergana Fault). The Chatkal-Kurama terrane experienced a phase of rapid cooling during the Triassic-Jurassic at ca. 225-190 Ma, which we interpret as a far-field response to the closure of the Palaeo-Asian Ocean or the accretion of the Qiangtang terrane on to the Eurasian margin. In the Late Jurassic to the Early Cretaceous, the Chatkal-Kurama terrane experienced a period of tectonic stability and denudation, before transitioning into a period of marine incursions of the Paratethys Sea. In contrast, fast cooling is recorded for the Kyrgyz central Tian Shan to the east of the Talas-Fergana Fault. The differing thermal histories at either side of the Talas-Fergana Fault suggest that the fault induced a topographic divide during the Late Jurassic-Early Cretaceous, with high relief in the east (Kyrgyz Tian Shan) and low relief to the west (Uzbek-Tajik Tian Shan). Finally, the Chatkal-Kurama terrane experienced renewed tectonic activity since ca. 30Ma, related with the distant India-Eurasia collision and Pamir indentation. The Cenozoic reactivation induced crustal tilting of the Chatkal-Kurama terrane, progressively exposing deeper rocks to the southwest.Plain Language Summary The Chatkal-Kurama terrane is the westernmost extent of the Tian Shan and one of the largest intracontinental mountain ranges in the world. The classical view of the plate tectonic paradigm implies that the majority of mountain building occurs at the margins of tectonic plates. Major ranges such as the Andes, the Himalaya, and the Rocky Mountains all form along the boundaries between major tectonic plates. However, the existence of major mountain ranges far from any modern plate boundary, such as the Tian Shan in Central Asia, forces us to consider how these intracontinental systems fit within the Earth system. These areas represent a unique challenge due to the complex nature of the tectonics, featuring multiple phases of deformation in response to far-field stress propagated from the plate margins into the continental interior. By using thermochronology in an intracontinental setting, such as the Chatkal-Kurama terrane, we aim to explore this complicated cooling history of the mountain ranges in this area and how that relates to the mountain growth in an intracontinental setting.

AB - The Chatkal-Kurama terrane represents a key region in understanding the tectonic evolution of the western Tian Shan. In this contribution, we present new thermochronological data (zircon [U-Th-Sm]/He, apatite fission track, and apatite [U-Th-Sm]/He) and the associated thermal history models for 30 igneous samples from the Chatkal-Kurama terrane within Uzbekistan and Tajikistan (west of the Talas-Fergana Fault) and integrate our data with published data from the central Tian Shan (east of the Talas-Fergana Fault). The Chatkal-Kurama terrane experienced a phase of rapid cooling during the Triassic-Jurassic at ca. 225-190 Ma, which we interpret as a far-field response to the closure of the Palaeo-Asian Ocean or the accretion of the Qiangtang terrane on to the Eurasian margin. In the Late Jurassic to the Early Cretaceous, the Chatkal-Kurama terrane experienced a period of tectonic stability and denudation, before transitioning into a period of marine incursions of the Paratethys Sea. In contrast, fast cooling is recorded for the Kyrgyz central Tian Shan to the east of the Talas-Fergana Fault. The differing thermal histories at either side of the Talas-Fergana Fault suggest that the fault induced a topographic divide during the Late Jurassic-Early Cretaceous, with high relief in the east (Kyrgyz Tian Shan) and low relief to the west (Uzbek-Tajik Tian Shan). Finally, the Chatkal-Kurama terrane experienced renewed tectonic activity since ca. 30Ma, related with the distant India-Eurasia collision and Pamir indentation. The Cenozoic reactivation induced crustal tilting of the Chatkal-Kurama terrane, progressively exposing deeper rocks to the southwest.Plain Language Summary The Chatkal-Kurama terrane is the westernmost extent of the Tian Shan and one of the largest intracontinental mountain ranges in the world. The classical view of the plate tectonic paradigm implies that the majority of mountain building occurs at the margins of tectonic plates. Major ranges such as the Andes, the Himalaya, and the Rocky Mountains all form along the boundaries between major tectonic plates. However, the existence of major mountain ranges far from any modern plate boundary, such as the Tian Shan in Central Asia, forces us to consider how these intracontinental systems fit within the Earth system. These areas represent a unique challenge due to the complex nature of the tectonics, featuring multiple phases of deformation in response to far-field stress propagated from the plate margins into the continental interior. By using thermochronology in an intracontinental setting, such as the Chatkal-Kurama terrane, we aim to explore this complicated cooling history of the mountain ranges in this area and how that relates to the mountain growth in an intracontinental setting.

KW - apatite fission track

KW - Tajikistan

KW - tectonics

KW - thermochronology

KW - Tian Shan

KW - Uzbekistan

KW - FISSION-TRACK

KW - APATITE

KW - U-PB

KW - EVOLUTION

KW - TECTONIC HISTORY

KW - (U-TH)/HE

KW - KYRGYZ TIEN-SHAN

KW - EXHUMATION HISTORY

KW - ASIAN OROGENIC BELT

KW - CLIMATIC IMPLICATIONS

UR - http://www.scopus.com/inward/record.url?scp=85055560223&partnerID=8YFLogxK

U2 - 10.1029/2017TC004878

DO - 10.1029/2017TC004878

M3 - Article

AN - SCOPUS:85055560223

VL - 37

SP - 3954

EP - 3969

JO - Tectonics

JF - Tectonics

SN - 0278-7407

IS - 10

ER -