黑龙江省砂宝斯金矿床成矿条件及成因探讨

砂宝斯金矿床为近年来在黑龙江省漠河县发现的-大型岩金矿床，产于中侏罗统陆相碎屑岩中，共有6条矿脉，走向近SN。金矿体严格受SN和NNW向断裂控制，围岩和侵入岩参与了成矿作用。通过流体包裹体的研究认为：成矿流体属于Ca^2＋（K^＋、Na^＋）-SO4^2-（F^-、Cl^-）型，具有低盐度（0．8wt％-9．2wt％）、低密度（0．895g／cm^3）、偏碱性（pH值为8．05～8．26）、高硫低氧（Logfo，值为-39．4～-39．2）和相对还原环境（Eh值为-0．71--0．68）的特点；成矿温度为200—230℃、成矿压力为40MPa，成矿深度为1．33km。矿石Pb、S、C、H和O同位素及岩（矿）石微量元素分析研究表明：金矿成矿物质来源于深部岩浆和地层；成矿流体主要来源于深部岩浆，有部分大气降水加入，是岩浆热液和大气降水的混合流体。砂宝斯金矿床的地质-地球化学特征与世界低硫化型浅成低温热液金矿类似，其成因类型属低硫化型浅成低温热液金矿床。

Ore-forming Conditions and Genesis of the Shabaosi Gold Deposit,Heilongjiang Province

The Shabaosi gold deposit in Mohe County, Heilongjiang Province, is a large gold deposit. It occurred in the Middle Jurassic continental clastic rock. There are six ore veins with nearly SN trend in the deposit. The ore bodies are strictly controlled by SN and NNW trend fault and the surrounding rocks and the intrusive rocks are involved in the mineralization. From the study of fluid inclusions, it is concluded that the ore-forming fluid belongs to Ca^2＋ （K^＋ , Na^＋）-SO]（F,Cl）type,which is characterized by the low salinity（0.8% -9.2% ）,low density（0. 895g/cm^3） ,alkali （ pH ： 8.05 - 8.26 ）, high sulfide, low oxidize （ Logfo2 ： -39.4 - -39.2 ） and relative reducing environment （ Eh ： -0.71- -0.68）. The ore-forming temperature ranges from 200 - 230℃ ,with pressure of 40MPa and depth of 1.33km. Based on the analysis of Pb, S, C, H and O isotopes and the study of microelements of the gold deposit, it is found that the ore-forming dements are from magma and strata in depth. The ore-forming fluids are mainly derived from magma in depth,with a little atmospheric water. The geological and geochemical characteristics of the Shabaosi gold deposit are similar to those of low sulphidation epithermal gold deposits in the world, and it belongs to low sulphidation epithermal gold deposit.