西北地质2026，Vol.59Issue(1)：60-78,19.DOI:10.12401/j.nwg.2025103
西秦岭李坝金矿床成因探讨:来自含金石英脉流体包裹体及锆石U-Pb年代学的证据
Genesis of the Liba Gold Deposit in West Qinling:Evidence from Fluid Inclusions and Zircon U-Pb Dating in Gold Bearing Quartz Vein
摘要
Abstract
The Liba gold deposit is located 2 km outside the Zhongchuan pluton in the West Qinling Orogen.Based on the latest exploration results of the Liba gold deposit,the geological characteristics are analyzed in de-tail,and the fluid inclusion and zircon U-Pb dating in the gold bearing quartz vein are studied.The mineralized alteration types of Liba gold deposit are pyritization,sericitization and silicification,which are obviously differ-ent with the metamorphic characteristics of the Zhongchuan pluton contact zone.Mineralized alteration,ore body and vein rock are strictly controlled by faults,but the scale and mineralization degree of vein rocks are lower than ore body,indicating that magmatic activity may not provide main fluid and material for metallogene-sis.The study of fluid inclusions indicate that the ores were deposited from medium-high temperature(220～360℃),low salinity(5%NaCleq～10%NaCleq)NaCl-H2O-CO2-(CH4)fluids,similar to metamorphic flu-id.The zircons in the gold bearing quartz veins are mostly sub rounded,indicating that they may undergone the process of transportation and rounding sedimentation.Zircon U-Pb ages can be divided into four spectral seg-ments:397～585 Ma,673～1 023 Ma,1 097～1 868 Ma,and 1 963～2 575 Ma,which are very close to the age characteristics of detrital zircons in the host rock Liba Group,indicating that they were captured from the stra-tum during the activation and migration of ore-forming fluid.The Liba gold deposit can be grouped with other orogenic gold deposits that have similar characteristics,which is formed under the transition tectonic back-ground from collision to extension.During the emplacement of Zhongchuan pluton,faults were developed along its margin,providing favorable spaces for the precipitation of ore-forming fluid and the emplacement of vein rocks.This caused the granitic pluton,vein rocks and gold bodies are together with space and time,but it may not have an inherent genetic relationship.关键词
李坝金矿床/流体包裹体/含金石英脉/锆石U-Pb年龄/造山型金矿床/西秦岭造山带Key words
Liba gold deposit/fluid inclusions/gold bearing quartz vein/zircon U-Pb dating/orogenic gold deposit/West Qinling Orogen分类
天文与地球科学引用本文复制引用
杨涛,朱赖民,胡妍,龙登红,王飞,夏云,刘伟刚,姜洪颖,刘子锐..西秦岭李坝金矿床成因探讨:来自含金石英脉流体包裹体及锆石U-Pb年代学的证据[J].西北地质,2026,59(1):60-78,19.基金项目
深地国家科技重大专项(2025ZD1009600),甘肃省2024年自然资源重点人才项目(2024-1),甘肃省自然科学基金项目(24JRRE017、23JRRA1396),自然资源部新一轮找矿突破战略行动科技支撑项目(ZKKJ202415)及国家自然科学基金项目(42173066)联合资助. （2025ZD1009600）
