摘要
据产出在闽北中生代陆相长英质火山质中受陷爆碎屑岩控制，以铀、银、钼共生为特征的５７０矿床流包裹体及氢、氧同位素研究表明，５７０矿床成矿温度为１５０－１８０℃，成矿流体以富含ＨＣＯ３、Ｆ、ＳＯ４＾２－、Ｋ、Ｎａ等组分为特征，铀主要以ＵＯ２（ＣＯ３）２＾２－，ＵＯ２（ＵＯ３）３＾４－、ＵＯ２Ｆ４＾２－、ＵＯ２Ｆ３形式运移，成矿富集作用与两种不同成因水溶液（火山热液和大气降水）的混合有关。对火山岩。
No 570 deposit, occurred in Mesozoic continental felsic volcanic rocks, is controlled by cryptoexplosive elastic rocks and characteristic of U-Ag-Mo paragenesis. The study of fluid inclusion showed that the ore-forming temperature is 150 -- 180℃, which belongs to the hydrothermal deposit of low to moderate temperatures; the fluid is enriched in HCO￣-_3, F-,SO￣2-_4, K+. Na+, but has comparative low salinity (1. 25 - 1. 48% NaCl equiv.) ;and uranium was migrated mainly as forms of UO2 (CO3)￣2-_2, UO2 (CO3￣4-_3, UO2F￣2-_4,UO2F￣-_3,in the ore--forming solution. According to hydrogen and oxygen isotope studies. the metallogenic enrichment of ore materials in No 570 deposit has close relationship to the mixing of two different solutions (volcanic hydrothermal solution and meteoric water). The geochemistry of Ph, S. C isotopes and trace elements from country rocks indicates that the ore--forming material of No 570 deposit has multiple sources and in close relationship with basement rocks. It is determined that uranium is contributed mainly by the Gaxi granite body and felsic volcanic rocks of the Nanyuan Formation. molybdenum is derived from volcanogenic hydrothermal solution, but silver is mainly from metamorphic rocks of the Mayuan Group. This paper suggests a metallogenic model of multisourced tectonomagmatic activation for No 570 deposit.
出处
《高校地质学报》
CAS
CSCD
1996年第2期187-197,共11页
Geological Journal of China Universities
基金
国家自然科学基金
关键词
隐爆碎屑岩
铀矿床
钼矿床
物理化学
银矿床
North Fujian
cryptoexplosive elastic rock. U-Ag-Mo paragenesis.
