地质学报2026，Vol.100Issue(3)：897-919,23.DOI:10.19762/j.cnki.dizhixuebao.2024277
白云鄂博矿区韧性变形、年代学及其地质意义
Ductile deformation and geochronology in the Bayan Obo ore district and their geological significance
摘要
Abstract
The Bayan Obo deposit is the largest comprehensive Fe-REE-Nb deposit in the world.The shape of ore bodies and the texture of ore are closely related to ductile structures.To understand the deformation characteristics and evolution of ore structures in the ore district,this study collected rocks for microscopic and Th-Pb geochronological analysis based on macroscopic structural analysis.Results show that rhombic,banded,and folded ore structures can be identified in the Bayan Obo deposit,which reflects gradually strengthening ductile deformation,involving minerals such as magnetite,monazite,fluorite,rare earth minerals,and dolomite.The most widely developed banded structures represent the products of ductile deformation of rocks during the compression stage.Selected syntectonic monazite gives a Th-Pb age of 432±4 Ma.Referring to previous geochronological results in the Bayan Obo deposit,it is believed that this age represents the ductile deformation occurs at the Middle Silurian.In addition,the coarse-grained monazite shows an age range of 838 Ma to 477 Ma and the geological significance represented by these ages is not yet clear.It may be related to the alteration of monazite during the mineralization by hydrothermal activity,resulting in a certain degree of lead loss.The U-Pb age of zircon in the undeformed diorite-porphyrite dyke is 274±4 Ma,which constrains the upper limit of ductile deformation.Combining regional geological results,it is suggested that the Middle Silurian ductile deformation in the Bayan Obo deposit corresponds to the collage between the North China plate and the Bainaimiao arc.The intense collision has transformed the original ore-forming structure from both macro-and microscopic aspects,forming the existing pattern.关键词
构造解析/构造控矿/独居石Th-Pb测年/白云鄂博/华北板块Key words
tectonic analysis/structural ore-control/monazite Th-Pb dating/Bayan Obo/North China Plate引用本文复制引用
王东升,马收先,诸泽颖,彭自栋,高玉璞,佘宏全,张丽,李以科,赵剑,柯昌辉,郭宾,苑星宇..白云鄂博矿区韧性变形、年代学及其地质意义[J].地质学报,2026,100(3):897-919,23.基金项目
本文为国家深地重大专项项目(编号2024ZD1001001)、国家重点研发计划项目(编号2022YFC2905301)、国家自然科学基金面上项目(编号42072114),中国地质科学院基本科研业务费项目(编号JKYQN202324)和中国地质科学院矿产资源研究所科技成果转化项目(编号HE2224、HE2228、HE2416、HE2332、HE2333、HE2334)联合资助的成果. （编号2024ZD1001001）
