摘要
本文总结北祁连山中西段塞浦路斯型铜矿特征及找矿标志 ,获得如下认识 :1成矿环境为奥陶纪亲弧扩张脊 (岛弧扩张脊和弧后扩张脊 ) ,容矿岩石为蛇绿岩套上部火山 -沉积岩系 ;矿床成矿金属组合为铜锌 ,贫铅 ;2矿床地质模型为蘑菇状 ,蘑菇茎代表沿热液通道的柱状矿体 ,蘑菇伞代表在热液喷流口周围海底展开的透镜状、似层状矿体 ,伞翼之下为基性火山岩 ,伞上常覆盖碧玉岩 ,成矿环境不稳定时 ,缺失碧玉岩。近喷流口位置矿体 Cu>Zn,远喷流口位置矿体 Cu<Zn;3成矿热液起源于海水与玄武岩在高温下的反应 ,成矿金属元素主要来自火山岩 ,矿化剂硫来自二者 ;4对于露头矿 ,地表存在硫化物氧化带 ,对于浅隐伏矿 ,地质标志是铜矿化与碧玉岩共存 ,地球化学标志是以铜为主的铜、锌套合异常 ,地球物理标志是存在电、磁组合异常。
The characteristics and prospecting indications of Cyprus type copper deposits in mid west sect of the North Qilian mountains are summarized in the paper And the conclusions are as follows: (1)The metallogenic setting was arc related spreading ocean ridges(island arc and back arc spreading ocean ridges) in Ordovician period The host rock belongs to volcanic rocks or volcanic sedimentary rocks in the upper part of ophiolite suite The assemblage of main metallogenic metals was Cu Zn type (2)The geological model of the deposits was mushroom shaped The stem of mushroom delegated columnar ore body along pathway of the hydrothermal solution and the umbrella of mushroom delegated lentoid and stratiform like ore body spreading in the seabed near the spout of the hydrothermal solution, as well as under limb of the umbrella, there is basic volcanic rock The umbrella is often covered by jaspilite, but no jaspilite exicts when the metallogenic setting was not steady The ore body was Cu>Zn near the spout of the hydrothermal solution ,and Cu<Zn far from the spout of the hydrothermal solution (3)The hydrothermal ore forming solution originated from reaction between sea water and basaltic rocks at high temperature, in which the ore forming metal elements came from the basaltic rocks and the sulfur from both the former and the latter (4)There is oxidized zone of sulfide in the outcrop deposits The superficial hidden deposits, there exist geological indication of copper mineralization and jaspilite,geochemical indication of copper and zinc register abnormity and geophysical indication of electricity and magnetism assembled abnormity
出处
《西北地质》
CAS
CSCD
2002年第4期65-85,共21页
Northwestern Geology
基金
中国地质调查局"甘肃北祁连山错沟-寺大隆一带铜矿预测与评价"项目 (编号 :2 0 0 0 10 2 0 0 15 2 )
关键词
成矿作用
找矿标志
祁连山
铜矿床
地质构造
成矿环境
the North Qilian mountains
arc related spreading ocean ridges
Cyprus type copper deposits
