摘要
系统测定了紫金山铜金矿床及外围矿化区和远景区蚀变岩石、矿物和石英中流体包裹体的年龄，对成岩成矿作进一步分期。在系统的Ｐｂ、Ｓｒ、Ｎｄ、Ｓ、Ｏ、Ｈ、Ｃ稳定同位素综合研究的基础上，应用Ｐｂ、Ｏ同位素地球化学示踪，在紫金山及其外围进行了找矿评价研究，首次发现蚀变岩石的Ｐｂ、Ｏ同位素组成随钻孔深度呈有规律的变化。在本区建立了两种成矿模式：（１）是低１８Ｏ和低２０６Ｐｂ／２０４Ｐｂ成矿，即δ１８Ｏ和放射成因铅（以２０６Ｐｂ／２０４Ｐｂ为找矿标志）降低的地方是矿体或矿化作用和蚀变作用强烈的地方。（２）高１８Ｏ和（或）高放射成因铅成矿，即δ１８Ｏ值和２０６Ｐｂ／２０４Ｐｂ比值升高的地方是矿体矿化部位或蚀变作用强烈的地方。
The zijinshan ore deposit is found recently as a new type of copper-gold deposit which is a mid-low temperature subvolcanic hydrotherm type copper-gold deposit related to volcanic neck phase docitic porphyrite and volcanic cryptoexplosion breccia in the Cretaceous volcanic eruption center.The ages are systematically determined by using Rb-Sr method for altered rocks and minerals and fluid inclusions in quartz from the copper-gold deposits of Zijinshan and its surrounding areas.The stages of diagenesis and mineralization are further divided.The main mineralization occured in Late Yanshanian period.On the basis of systematic and comptehensive Pb,Sr,O,S,H and C stable isotope studies,and by using Pb and O isotope geochemical tracing method,the research is made on the exploration assessment.It is first discovered that the Pb and O isotope compositions of the altered rocks change regularly with the drill hole depth.Two models are estoblished from Zijinshan and its surrounding areas:(1)mineralization with lower δ18O and 206Pb/204Pb values,i.e.where theδ18O value and radiogenic lead(206Pb/204Pb is used as the exploration mark) decreas is the place of orebody;(2)mineralization with high δ180 and high radiogenic lead,i.e.where the δ18O value and 206Pb/204Pb ratio increase is the place of orebody or the positin of intensive mineralization.
出处
《大地构造与成矿学》
EI
CAS
CSCD
1996年第4期348-360,共13页
Geotectonica et Metallogenia
关键词
铜矿床
金矿床
成矿年代
同位素
找矿
mineralization chronology,isotope geochemical tracer,Zijinshan copper-gold deposit
