广西大厂锡多金属矿田深部碳酸盐岩的碳、氧同位素特征及其对于深部找矿的意义  

C,O Isotopic Compositions of Carbonate Rocks and its Significance for Deep Prospecting in the Dachang Tin-Polymetallic Deposit,Guangxi

作　　者：秦燕[1] 王登红[1] 梁婷[2] 李建康[1] 

机构地区：[1]国土资源部成矿作用与资源评价重点实验室中国地质科学院矿产资源研究所,北京100037 [2]长安大学地球科学与资源学院,陕西西安710054

出　　处：《大地构造与成矿学》2014年第2期359-365,共7页Geotectonica et Metallogenia

基　　金：国家深部探测技术与实验研究专项课题(编号:SinoProbe 0301);中国地质大调查项目(编号:1212011120989,1212010633903,1212011120354);国家自然科学基金青年基金(编号:41103004)联合资助

摘　　要：以广西大厂超大型锡多金属矿田深部钻探 ZK39-1钻孔获得的新鲜岩心为研究对象,详细分析了钻遇中下泥盆统灰岩样品的碳、氧同位素组成及矿化元素含量。结果表明,各类样品的δ18OV-SMOW为12.07‰~24.31‰,钻孔深度1000 m以下岩心样品的δ18OV-SMOW明显偏低；δ13CV-PDB为-4.6‰~1.7‰,1000 m以下样品的δ13CV-PDB逐步降低。岩心碳、氧同位素组成负异常的部位同时也出现了矿化元素显著的正异常,由此推测1000 m深度以下存在热液流体活动。研究表明,钻孔岩心碳酸盐岩样品的碳、氧同位素组成的变化规律可以提供蚀变作用及相关流体的重要信息,可作为一种重要的找矿标志,从而为深部找矿勘查提供科学依据。This paper takes the limestone samples, which drilled from the drill hole of ZK39-1 in the Dachang Tin-Polymetallic Ore Field, as the study object. Carbon and oxygen isotopes, together with ore metal contents of the limestone samples were analyzed. The δ18OV-SMOW values of all the samples range from 12.07‰ to 24.31‰, and decrease obviously for samples below the depth of 1000 meters. Theδ13CV-PDB values of all the samples are distributed between-4.6‰to 1.7‰, and also decrease at the depth of 1000 meters like theδ18OV-SMOW values. In this drilling core, while the carbon and oxygen isotope values decrease, however, the ore metal contents increase at depth below 1000m. We conclude that the limestones experienced hydrothermal alteration below 1000 meters depth. Our results show that the variation of carbon and oxygen isotopic compositions of carbonate samples from drill core can provide important information about the alteration and the fluids, which can be used as an important scientific evidence for deep prospecting.

关 键 词：碳酸盐岩 碳 氧同位素 矿化元素 深部找矿 广西大厂超大型锡矿田 

分 类 号：P597.2[天文地球—地球化学] P612[天文地球—地质学]