地质找矿论丛2025，Vol.40Issue(4)：524-532,9.DOI:10.6053/j.issn.1001-1412.2025.04.009
大兴安岭中南段都兰地区满克头鄂博组火山岩年代学、地球化学及成因研究
Geochronology,Geochemistry and Genesis of Volcanic Rocks from the Manketouebo Formation in the Dulan Area,the Middle and Southern Sections of the Greater Kh-ingan Range
摘要
Abstract
The tectonic setting during the formation of Mesozoic volcanic rocks in the Greater Khingan Range has long been a focal issue of concern to geologists.Previous studies have primarily focused on Early Cretaceous volcanic rocks,with rela-tively little research on Late Jurassic volcanic rocks.In this paper,Late Jurassic volcanic rocks in the Dulan area of eastern In-ner Mongolia are selected as the research object.To clarify the formation age,magmatic source characteristics,and tectonic setting of this suite of volcanic rocks,systematic petrogeochemical analyses,zircon U-Pb geochronological analyses,and pet-rogenetic discussions were carried out,aiming to provide new geological data and evidence for studying the formation back-ground of regional Mesozoic volcanic rocks.Through LA-ICP-MS zircon U-Pb dating,the age of Late Jurassic volcanic rocks in the Dulan area is determined to be 153.9±1.5 Ma,which clarifies the precise formation age of volcanic rocks in the Manke-touebo Formation in this area,indicating that there was a peak period of volcanic rock formation in the southern segment of the Greater Khingan Range during the Late Jurassic.Volcanic rocks of the Manketouebo Formation in the Dulan area are dominated by intermediate-to acidic volcanic rocks,such as rhyolite and rhyolitic tuff.Petrogeochemical analysis data show that this suite of volcanic rocks has distinct compositional characteristics:they belong to the high-K calc-alkaline series rhyo-lites,with major elements characterized by high silica,alkali-rich,and high potassium contents.Rare earth element(REE)patterns exhibit a right-inclined shovel-like feature,indicating enrichment of light rare earth elements(LREEs)and relative depletion of heavy rare earth elements(HREEs),with significant negative Eu anomalies.Trace element data of the volcanic rocks show high concentrations of large-ion lithophile elements(LILEs,such as Rb,Th,U)and low concentrations of high-field-strength elements(HFSEs,such as Nb,P,Ti).In combination with the regional tectonic evolution,petrological and geo-chemical data indicate that this suite of volcanic rocks formed in a post-orogenic extensional setting.The magma was derived from the partial melting of crustal rocks,and the magmatic evolution was related to the extensional tectonic background after the closure of the Mongol-Okhotsk Ocean.关键词
锆石U-Pb年代学/地球化学/岩石成因/满克头鄂博组/都兰/大兴安岭中南段Key words
zircon U-Pb chronology/geochemistry/petrogenesis/Manketouebo Formation/Dulan Area/the middle and south-ern sections of the Greater Khingan Range分类
天文与地球科学引用本文复制引用
韩荣文,何鹏,赵子军,蒋园,杨圣坤,朵兴芳,徐方..大兴安岭中南段都兰地区满克头鄂博组火山岩年代学、地球化学及成因研究[J].地质找矿论丛,2025,40(4):524-532,9.基金项目
中国地质调查局项目"燕山-太行成矿带区域地质调查"([2025]01-023/DD202401023)资助. （[2025]01-023/DD202401023）
