地质通报2023，Vol.42Issue(12)：2109-2120,12.DOI:10.12097/j.issn.1671-2552.2023.12.007
内蒙古扎兰屯地区晚三叠世哈拉苏斑状正长花岗岩的成因:锆石U-Pb年龄、Hf同位素和地球化学证据
Genesis of Late Triassic Harasu porphyritic syenogranite in Zalantun area,Inner Mongolia:Zircon U-Pb age,Hf isotope and geochemical evidence
摘要
Abstract
In this paper,the geochronology,geochemistry and Hf isotopic composition of the Harasu porphyritic syenogranite in Zalantun,Inner Mongolia were studied.LA-ICP-MS zircon dating indicates that the Harasu porphyritic syenogranite was emplaced during the Late Triassic(213.17±0.93 Ma).The mineral assemblage is mainly composed of quartz,alkaline feldspar and plagioclase.The Harasu porphyritic syenogranite is characterized by high SiO2(72.56％～74.36％),K2O(4.74％～5.49％),low MgO(0.12％～0.34％),CaO(0.54％～0.95％),TiO2(0.19％～0.29％)and P2Os(0.042％～0.053％),A/CNK=1～1.05,＜1.1.It is strongly depleted in Ba,Sr,Eu,P and Ti,showing the geochemical characteristics of aluminous A-type granite.The Harassu A-type granites have highεHf(t)values(+9.08～+15.3),which may due to the partial melting of new meso-basic crustal materials.The Harasu A-type granite is recognized as the product of a post-orogenic tectonic.The crust in Zalantun area was thickened and transformed into a post orogenic extension mechanism,which may be affected by the remote effect of the closure of the Paleo-Asian Ocean,and then the Late Triassic Harasu porphyritic syenogranite in Zalantun area was formed.关键词
A型花岗岩/晚三叠世/地球化学/锆石U-Pb测年/内蒙古扎兰屯/地质调查工程Key words
A-type granite/Late Triassic/geochemistry/zircon U-Pb dating/Zalantun,Inner Mongolia/geological survey engineering分类
天文与地球科学引用本文复制引用
胡鹏,段明,熊金莲,曾威,刘行,闫国强,魏佳林..内蒙古扎兰屯地区晚三叠世哈拉苏斑状正长花岗岩的成因:锆石U-Pb年龄、Hf同位素和地球化学证据[J].地质通报,2023,42(12):2109-2120,12.基金项目
中国地质调查局项目《铀铁铜铝等战略性矿产资源调查》(编号:DD20230027)、《华北豫西等重点成矿区带铝铜镍等矿产地质调查》(编号:DD20221686)、《内蒙古阿拉善-河套地区区域地质调查》(编号:DD20211191) （编号:DD20230027）
