Hisingerite in Trachydacite from Tarim:Implications for Voluminous Felsic Rocks in Transitional Large Igneous Province  

作　　者：Mingde Lang Zhiguo Cheng Zhaochong Zhang Fangyue Wang Qian Mao M.Santosh 

机构地区：[1]State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China [2]Ore Deposit and Exploration Centre(ODEC),Hefei University of Technology,Hefei 230009,China [3]State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [4]Department of Earth Sciences,University of Adelaide,SA 5005,Australia

出　　处：《Journal of Earth Science》2020年第5期875-883,共9页地球科学学刊（英文版）

基　　金：the National Natural Science Foundation of China (Nos. 41772057, 41702064);the Fundamental Research Funds for the Central Universities (Nos. 2652018118, PA2018GDQT0020)。

摘　　要：Unlike the typical large igneous provinces(LIPs) that are dominated by mafic-ultramafic rocks, the Tarim large igneous province(TLIP) is characterized by a high proportion of felsic rocks, based on which the TLIP is classified as a transitional LIP. In this study, we focus on the trachydacite from the TLIP in which we report the characteristics of hisingerite employing a variety of techniques such as EMPA, LA-ICPMS, CCD single crystal diffraction, and bulk-rock oxygen isotopes. The hisingerite in this rock is associated with plagioclase, amphibole, apatite and ilmenite. These minerals occur as aggregates of fine curled fibers in micron-scale and display heavy rare earth elements(HREE) enriched signature with significant negative Eu anomalies. In the primitive mantle-normalized trace element spider diagrams, they show pronounced Th and U spikes and Nb, Zr, Hf troughs. Petrological observation and mineralogical study reveal a closely genetic relationship between hisingerite and amphibole, indicating that the hisingerite might have been derived from the breakdown of amphibole during the magma ascent. The formation of hisingerite requires excess water from the surrounding melts, suggesting a hydrous parental magma. The hisingerite and amphibole assign a hydrous crustal source for the rock, and extensive crustal melting accounts for the voluminous felsic rocks in the TLIP.

关 键 词：hisingerite amphibole trachydacite hydrous crust Tarim large igneous province 

分 类 号：P618.32[天文地球—矿床学]