摘要
本文通过对河台金矿流体包裹体的研究,从包裹体一般特征,成矿温度、压力,成矿流体特征、来源等方面系统分析了成矿的物理化学条件,并进一步探讨了成矿流体在不同成矿期、不同成矿阶段的演化以及流体的演化在成矿过程中的意义。通过这些研究,结合成矿地质条件、矿床地质特征以及矿物学等方面的研究成果,提出了本区的找矿方向。
Located in Yunkai Mountains, western Guangdong, and controlled by a ductile shear zone, the Hetai deposit is an important gold deposit in South China. Fluid inclusion studies show that ore-forming fluids are of the H_2O-CO_2-NaCl system, and metallogenic environments are noted for moderate to low temperatures (350～220℃), low salinities (3.50～10.50wt% NaCl), weak acidity (pH=4.57～4.17), low f_(O_2), (10^(-35)～10^(-44) bar), low f_(S_2), (10^(-7)～10^(-16) bar) and pressures of 1200～1000 bar. Ore-forming fluids are characterized by K^+> Na^+, Ca^(2+)>>Mg^(2+) Cr^->>F^-, CO_2>CH_4 and abundant K^+, Na^+, Cl^-, Ca^(2+) and Mg^(2+). Ore-forming fluids, derived mainly from metamorphic and magmatic waters, changed gradually in composition from the ductile shearing phase through the gold-quartz stage of the brittle deformation phase to the gold-quartz-sulfide stage.
The conversion from ductile deformation to brittle deformation resulted in the mineralization and concentration of gold in the ore district.
Great gold-hunting potentiality exists in Yunkai area, where 'Hetai type' gold deposits, 'quartz vein type' gold deposits and 'sedimento-metamorphic type' gold deposits might be further discovered. The eastern part of the No. 11 orebody might extend to a depth of some -400 m and plunge laterally towards the Houjing deposit. Mineralization is poor in the depth of the No. 12 orebody of the Houjing deposit and between the Gaocun and the Yunxi deposit; nevertheless, the depth of the No, 9 orebody of the Yunxi deposit seems rather promising.
出处
《矿床地质》
CAS
CSCD
北大核心
1993年第2期120-128,共9页
Mineral Deposits
