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Development of a complex arc–back-arc basin system within the South Tianshan Ocean: Insights from the Wuwamen ophiolitic peridotites

Authors :
Peng-Yu He
Zheng-Yu Yang
Qi-Song Luo
Ji-Feng Xu
Xiao-Han Gong
Xijun Liu
Hai-Long Zhou
Xiao-Xiao Huang
Zhiguo Zhang
Source :
Lithos. :106487
Publication Year :
2021
Publisher :
Elsevier BV, 2021.

Abstract

Ophiolites within the South Tianshan orogenic belt directly record the nature and tectonic evolution of the South Tianshan Ocean (STO), which is key for understanding the accretionary history of the Central Asian Orogenic Belt. Here we present petrological and Os isotopic data for the Wuwamen mantle peridotites from the South Tianshan orogenic belt, which provide new insights into the tectonic origin of this ophiolite and evolution of the STO. The lherzolites have low spinel Cr# (0.1–0.2), similar to those of fertile oceanic or continental peridotites that have undergone low degrees of melting. However, the extremely high Na2O (1.5–1.8 wt%) and Al2O3 (5.5–6.2 wt%) contents of the clinopyroxenes are atypical of oceanic peridotites, and resemble those of subcontinental peridotites. The harzburgites have more refractory compositions, suggesting higher degrees of melt extraction. Both the lherzolites and harzburgites have low initial 187Os/188Os ratios (

Details

ISSN :
00244937
Database :
OpenAIRE
Journal :
Lithos
Accession number :
edsair.doi...........08cead5af40ccb923af7615f7dc6001d
Full Text :
https://doi.org/10.1016/j.lithos.2021.106487