TY - JOUR

T1 - Detrital zircon record of the early Paleozoic meta-sedimentary rocks in Russian Altai

T2 - Implications on their provenance and the tectonic nature of the Altai-Mongolian terrane

AU - Chen, Ming

AU - Sun, Min

AU - Cai, Keda

AU - Buslov, Mikhail M.

AU - Zhao, Guochun

AU - Rubanova, Elena S.

AU - Voytishek, Elena E.

PY - 2015/9/15

Y1 - 2015/9/15

N2 - An integrated U-Pb and Hf-isotope study on detrital zircons from the early Paleozoic meta-sedimentary rocks along the Chalysh-Terekta-Ulagan-Sayan suture zone in Russian Altai was conducted in order to trace their provenance and tectonic setting. Most of the zircons possess oscillatory zoning and high Th/U ratios (>0.1), indicating their magmatic origin. The investigated samples yield similar zircon populations, i.e., dominant groups with late Neoproterozoic to early Paleozoic ages, followed by those from Mesoproterozoic to late Neoproterozoic and minor ones from Archean to middle Mesoproterozoic, indicating multiple tectono-thermal events in the source area. Comparison with surrounding tectonic units shows that the Tuva-Mongolian terrane and its adjacent island arcs possibly provided substantial materials to the sedimentary basin. These rocks show detrital zircon age patterns and Hf-isotope compositions similar to their counterparts in the Chinese Altai and Tseel terrane in western Mongolia, but different from those in the Gomy Altai terrane. Therefore, the investigated metasedimentary units possibly represented the northernmost segment of the Altai-Mongolian terrane. With combination of previous studies in the Chinese Altai and Tseel terrane, our data suggest that the Altai-Mongolian terrane possibly represents a coherent continental arc-accretionary prism system built upon the active margin of the western Mongolia during the Cambrian to Ordovician and thus does not support the micro-continent model with a passive margin.A compilation of U-Pb and Hf-isotope data of detrital zircons from the whole Altai-Mongolian terrane shows that the source area (i.e., the western Mongolia) underwent two most extensive magmatic activities at ca. 1.02-0.67 Ga and 0.67-0.43 Ga. These zircons possess both positive and negative epsilon(Hf)(t) values, suggesting significant crustal growth and reworking during the magmatic activities. Our study underlines a crucial role of Precambrian micro-continents (e.g., the Tuva-Mongolian terrane) and island arcs surrounding them in the formation of the Central Asian Orogenic Belt. (C) 2014 Elsevier B.V. All rights reserved.

AB - An integrated U-Pb and Hf-isotope study on detrital zircons from the early Paleozoic meta-sedimentary rocks along the Chalysh-Terekta-Ulagan-Sayan suture zone in Russian Altai was conducted in order to trace their provenance and tectonic setting. Most of the zircons possess oscillatory zoning and high Th/U ratios (>0.1), indicating their magmatic origin. The investigated samples yield similar zircon populations, i.e., dominant groups with late Neoproterozoic to early Paleozoic ages, followed by those from Mesoproterozoic to late Neoproterozoic and minor ones from Archean to middle Mesoproterozoic, indicating multiple tectono-thermal events in the source area. Comparison with surrounding tectonic units shows that the Tuva-Mongolian terrane and its adjacent island arcs possibly provided substantial materials to the sedimentary basin. These rocks show detrital zircon age patterns and Hf-isotope compositions similar to their counterparts in the Chinese Altai and Tseel terrane in western Mongolia, but different from those in the Gomy Altai terrane. Therefore, the investigated metasedimentary units possibly represented the northernmost segment of the Altai-Mongolian terrane. With combination of previous studies in the Chinese Altai and Tseel terrane, our data suggest that the Altai-Mongolian terrane possibly represents a coherent continental arc-accretionary prism system built upon the active margin of the western Mongolia during the Cambrian to Ordovician and thus does not support the micro-continent model with a passive margin.A compilation of U-Pb and Hf-isotope data of detrital zircons from the whole Altai-Mongolian terrane shows that the source area (i.e., the western Mongolia) underwent two most extensive magmatic activities at ca. 1.02-0.67 Ga and 0.67-0.43 Ga. These zircons possess both positive and negative epsilon(Hf)(t) values, suggesting significant crustal growth and reworking during the magmatic activities. Our study underlines a crucial role of Precambrian micro-continents (e.g., the Tuva-Mongolian terrane) and island arcs surrounding them in the formation of the Central Asian Orogenic Belt. (C) 2014 Elsevier B.V. All rights reserved.

KW - Detrital zircon

KW - Provenance

KW - Altai-Mongolian terrane

KW - Arc-accretionary prism

KW - ASIAN OROGENIC BELT

KW - PHANEROZOIC CRUSTAL GROWTH

KW - ND ISOTOPIC EVIDENCE

KW - U-PB GEOCHRONOLOGY

KW - ISLAND-ARC SYSTEM

KW - GORNY-ALTAI

KW - CHINESE ALTAI

KW - CONTINENTAL-CRUST

KW - WESTERN MONGOLIA

KW - LAKE ZONE

U2 - 10.1016/j.lithos.2014.11.023

DO - 10.1016/j.lithos.2014.11.023

M3 - Article

VL - 233

SP - 209

EP - 222

JO - Lithos

JF - Lithos

SN - 0024-4937

ER -