Tectonic Setting of Hadahushu Mafic Intrusionin Urad ZhongqiArea,Inner Mongolia:Implications for Early Subduction Histor of Paleo-Asian Ocean Plate
Liu Jinlong
Sun Fengyue
Wang Yingde
Li Liang
Zhang Yuting
Xin Wei
Hu Anxin
Abstract：The Urad Zhongqi area of western Inner Mongolia crosses the North China Plate margin and Xing'an-Mongolia Oro-genic Belt,which distributed regional basic rock massif occurred as small stocks,and a lack of reliable data of intrusion age. This paper reports LA-ICP-MS zircon U-Pb dating,geochemical and Hf isotopic data of Hadahushu mafic intrusion in Urad Zhongqi area,with the aim of constraining its petrogenesis and the beginning time of subduction of the Paleo-Asian oceanic plate.LA-ICP-MS U-Pb dating results of zircons from the mafic intrusion indicate that the intrusion formed at the Late Cam-brian (513±2 Ma).The geochemical characteristics of these rocks indicate that they are the calc-alkaline series,and are char-acterized by enrichment in LILE (such as K,Ba,Rb),relatively depleted in HFSE (such as Nb,Ta ,Zr,Ti)and LREE.TheεHf (t)values and one-stage model ages (TDM1 )of zircons from the rock vary from 14.15 to 15.03 and from 518 to 556 Ma,respectively. These characteristics suggest that the primary magma was derived from the depleted lithospheric mantle source.Based on the previous study,we conclude that the formation of mafic intrusion was related to the subduction of the Paleo-Asian oceanic plate.
Keywords：geochronologyzircon Hf isotopemafic intrusionUrad Zhongqigeochemistry
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 2019-2030 )