摘要
碧田矿床是成因上与燕山晚期次火山岩有关的以银为主的大型铜金银矿床。金属矿物种类复杂，除常见的黄铁矿、黄铜矿、斑铜矿外，还有多种铜铋硫盐矿物（锌砷黝铜矿、铋砷黝铜矿、铋锑黝铜矿、针硫铋铅矿、硫铋铜矿）、钨锡硫化物（硫铁锡铜矿、硫钨锡铜矿）及多金属硫化物。金银矿物除辉银矿外，主要是Ａｕ－Ａｇ系列的自然金、银金矿、金银矿及自然银。这些矿物形成于不同的物理化学条件下，大多数铜矿物、铜铋硫盐矿物和钨锡硫化物是在中高温（２６０—３８０℃）条件下、硫逸度较高（ｌｇｆＳ２＝－８．７４—－１２．０６）、流体盐度高并处于沸腾的状况下形成的；而多金属硫化物和金银矿物则主要是在中低温（１２０—２６０℃）条件下，硫逸度较低（ｌｇｆＳ２＝－１１．６—－１９．５），流体盐度也较低的状况下形成的。
The Bitian ore deposit is a silver-dominant large-size copper-gold-silver deposit related to Late Yanshanian subvolcanic rocks. Species of metallic deposits are quite complicated:Besides commonly-seen pyrite, chalcopyrite and bornite, there exist varied copper-bismuth sulfosalt minerals (sandbergerite, Bi-tennantite, Bi-tetrahedrite, aikinite, wittichenite), tungsten-tin sulfides (mawsonite, kiddcreekite) and polymetallic sulfides. In addition to argentite, gold-silver minerals mainly include native gold, electrum, kiistelite and native silver of gold-silver series. These minerals were formed at bornite-chalcopyrite-pyrite stage, gold-silver polymetallic sulfide stage and native silver-quartz stage respectively under different physicochemical conditions.Most chalcopyrite, bornite, copper-bismuth sulfosalt minerals and tungsten-tin sulfides were formed under the conditions of medium-high temperature (260-380℃), relatively high sulfur fugacity (1g f S 2=-8.74—-12.06), high salinity of fluids and boiling, whereas polymetallic sulfides and gold-silver minerals were formed under the conditions of medium-low temperature (120—260℃), comparatively low sulfur fugacity (lg f S 2=-11.6—-19.5) and also relatively low salinity of fluids. The discovery of varied types of copper-bismuth sulfosalt minerals indicates a certain degree of bismuth enrichment in the Bitian silver-dominant large-size copper-gold-silver deposit. Therefore, importance should be attached to the study of the mode of occurrence of bismuth.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
1997年第3期260-270,共11页
Acta Petrologica et Mineralogica
基金
中国地质科学院资助
关键词
福建
铜矿床
金矿床
银矿床
金属矿物
metallic mineral
ore-forming stage
physicochemical condition
copper-gold-silver deposit
Fujian
