摘要
据新疆阿尔泰新发现的多拉纳萨依、沙尔布拉克等７－９个成型金矿的成矿流体化学成分、盐度、密度、矿化度、还原参数、成矿温度、成矿压力、氧逸度、硫逸度、ｐＨ值、Ｅｈ值、硫同位素、碳氧同位素和氢氧同位素的系统研究认为，矿床成矿物质具多来源，但主要来源于围岩；成矿溶液水介质也具多来源，但主成矿阶段主要来源于大气降水；成矿环境以富碱质元素的中性－弱碱性强还原中低温低压环境为主；矿床具多期多阶段、多成因特点。
The arc-trench system developing in the Altay area,Xinjiang,is called the Ertix tectono-magmatic domain, and is similar to the present one in West Pacific.It originated from the subduction of the North TianshanJunggar plate toward the Siberian continental plate during the Variscan period.The arc-trench system is composed of five tectono-magmatic metallogenic belts,including trench,island arc,back-arc basin,continental-margin plutonic-magmatic arc and intraplate volcanic fault basin.Gold deposits occur in each belt. The studies on metallogenic geochemistry of the gold deposits occurring in the Altay area show that the mineralizing fluid is characterized by:1) the dominance of Ca2+,K+,Na+,HCO-3 and SO2-4 in the liquid phase and CO and CO2, in the gas phase;2) a salinity of less than 10.0% eq.NaCl,a density of less than 1.0g/cm3,mineralization intensity of 13.7-310.7 and reduction parameter of 0. 12-17. 02; 3) mineralization temperature range from 160 to 300℃ and pressure from 7. 34 to 70. 30MPa;4) lgfo2=-26.5--48.7 and lgfs2=-6. 5--15.5;5) PH =6.37-7.21 and Eh =-0.60--0. 81V,and 6) δ34S,δ18OH2O and δD range from -7.02‰ to +6.20‰,from -7.56‰ to +11.23% and from-37.0‰,to-142.2‰,In summary,those gold deposits formed in a neutrally to weakly alkaline,strongly reducing,medium to low temperature and low pressure environment.The gold deposits are of polyphase,polystage,poly-genesis and polysource.They formed in an open system.
出处
《地球化学》
CAS
CSCD
北大核心
1994年第C00期58-67,共10页
Geochimica
基金
"七五"国家重点科技攻关项目
