小秦岭华阳川铀多金属矿床新生代隆升剥露的裂变径迹证据  

Fission track evidence of Cenozoic uplift and exhumation of Huayangchuan uranium polymetallic deposit in Xiaoqinling

作　　者：陈智柏 严杰 孙岳[1,3] 康清清 潘春蓉 夏菲[3] 潘家永[3] CHEN Zhibai;YAN Jie;SUN Yue;KANG Qingqing;PAN Chunrong;XIA Fei;PAN Jiayong(College of Earth Sciences,East China University of Technology,Nanchang,Jiangxi 330013,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang,Jiangxi 330013,China;Geological Party No.224 Sino Shaanxi Nuclear Industry Group,Xi'an,Shaanxi 710000,China)

机构地区：[1]东华理工大学地球科学学院,江西南昌330013 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]东华理工大学,核资源与环境国家重点实验室,江西南昌330013 [4]中陕核工业集团二二四大队有限公司,陕西西安710000

出　　处：《地质学报》2025年第3期794-808,共15页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号42262017,41902075,42172098);江西省自然科学基金项目(编号20212BAB213009);江西省教育厅科技计划项目(编号GJJ200767);中国铀业有限公司-东华理工大学联合创新基金项目(编号2023NRE-LH-12,NRE2021-01,NRE2021-09)联合资助的成果。

摘　　要：华阳川铀多金属矿床是一个以铀铌铅为主并伴生稀土元素的综合性超大型矿床。为理清该矿床的剥露历史和矿体保存情况,本文依据矿体展布特征在华阳川矿区系统采集10个片麻岩样品,进行磷灰石裂变径迹测试。径迹结果显示,样品的径迹年龄介于52.0±2.9~35.2±0.8 Ma之间,平均径迹长度为11.5~13.7μm。热史模拟显示,华阳川地区新生代以来主要经历了始新世(54~34 Ma)和中中新世至今(13~0 Ma)2期快速隆升剥露,以及渐新世至中中新世(34~13 Ma)缓慢剥蚀过程。结合区域构造演化,构建了华阳川地区新生代构造演化模式,认为该地区始新世时期的快速隆升剥蚀是受小河断裂自南向北逆冲推覆以及华山山前断裂伸展活动共同影响;34~13 Ma期间研究区整体处于构造寂静期;13 Ma以来快速隆升剥露主要受华山山前断裂影响,导致研究区发生北仰南倾的掀斜。裂变径迹数据和热史模拟表明研究区南东侧矿体保存状况良好,找矿潜力较大。The Huayangchuan uranium polymetallic deposit,a super-large,comprehensive deposit dominated by U-Nb-Pb with associated rare earth elements,presents a compelling case study for understanding the interaction of geological processes and ore body preservation.To unravel the exhumation history of this deposit,a systematic apatite fission track analysis was conducted on 10 gneiss samples strategically collected from the Huayangchuan mining area,guided by the distribution of the ore body.The results show that the obtained fission track ages range from 52.0±2.9 to 35.2±0.8 Ma,with average track lengths between 11.5 and 13.7μm.Thermal history simulations,based on these data,indicate two distinct periods of rapid uplift and denudation in the Huayangchuan area since the Cenozoic:the Eocene(54~34 Ma)and the Middle Miocene to present(13~0 Ma),with a period of tectonic quiescence from the Oligocene to Middle Miocene(34~13 Ma).Integrating the fission track data with regional tectonic evolution,a comprehensive Cenozoic tectonic evolution model for the Huayangchuan area is constructed.It is considered that the rapid uplift and denudation in the Eocene period are attributed to the southward-to-northward thrusting of the Xiaohe fault and the extension of the Huashan piedmont fault.During the 34~13 Ma period,the study area experienceda period of relative tectonic quiescence.The rapid uplift and exhumation since 13 Ma are mainly affected by the Huashan piedmont fault,resulting in a north-to-south tilt of the study area.The fission track data and thermal history simulation show that the ore bodies located on the southeast side of the study area are well-preserved and have great prospecting potential.

关 键 词：磷灰石裂变径迹 铀多金属矿床 隆升剥露 华阳川 

分 类 号：P61[天文地球—矿床学]