初论浅成作用和热液矿床成因分类

通过简单列举现有金矿床类型的名称,发现热液矿床分类命名混乱、繁杂、缺乏科学逻辑,严重制约着教学、科研和找矿勘探事业的发展,原因是对于深度<10 km、温度为50~300 ℃条件下的地质作用研究薄弱,缺乏概念描述,构成认识盲区,因此提出了浅成作用(epizonogenism)的概念,用于概括深度<10 km、温度为50~300 ℃条件下的地质作用。藉此将热液矿床划分为浅成热液、变质热液和岩浆热液等3个成因端员;确定浅成、变质和岩浆流体的特征分别是低盐度 贫CO₂、低盐度 富CO₂和高盐度 CO₂含量变化大;岩浆热液矿床发育含多种子晶包裹体和高盐度富CO₂的包裹体,变质热液矿床发育低盐度富CO₂包裹体,浅成热液矿床只发育水溶液包裹体,缺乏含子晶包裹体和富/含CO₂包裹体。

On epizonogenism and genetic classification of hydrothermal deposits

This paper, through listing the genetic type names of hydrothermal gold deposits presented in literatures, reveals that the existing genetic classifications of hydrothermal deposits are scientifically illogical, confusing and abusive, without satisfactory connection to logics in other geoscience disciplines. This greatly hinders the ore geological training, research and exploration targeting, and is resulted from a conceptual gap of the geological processes occurred at depths less than 10 km and temperatures of 50 - 300 ℃. Hence we propose a concept of epizonogenism to describe the geological processes occurred at depths of <10 km and temperatures of 50 - 300 ℃. In correspondence, hydrothermal deposits are classified into three end-members, namely epizonogenic, metamorphic and magmatic. It is confirmed that the epizonogenic fluids are characterized by low-salinity and CO_2-poor, the metamorphic fluids by low-salinity and high-content of CO_2-rich, and the magmatic fluids by high-salinity and variable content of CO_2. The magmatic hydrothermal systems contain multiple daughter-crystals-bearing and CO_2-rich high-salinity fluid inclusions; the metamorphic deposits contain low-salinity CO_2-rich fluid inclusions; and the epizonogenic hydrothermal systems contain neither daughter-crystal-bearing nor CO_2-rich/bearing fluid inclusions, but are populated by aqueous fluid inclusions.