山东金山金矿床成矿流体特征和成矿作用

Metallogenic Fluid Characteristics and Mineralization of Jinshan Gold Deposit in Shandong Province

金山金矿床产于栖霞市北大庄子—金山—小庄韧脆性剪切带内,空间上与中生代中基性脉岩关系密切。流体包裹体研究表明成矿流体早期为低盐度、低密度富CO2的NaCl-H2O-CO2体系,之后由于沸腾作用逐渐演化成NaCl-H2O盐水体系,矿床形成温度为165-280℃,成矿深度为2.33-3.00 km,属中浅成深度中低温热液矿床。同位素研究表明成矿流体早期以岩浆水为主,晚期混入大量大气降水,成矿物质主要来源于中生代脉岩,胶东古老变质基底亦有一定贡献。成矿机理主要是由于沸腾作用和大气降水的混合作用引起流体物理化学性质变化。

Jinshan gold deposit locates in Dazhuangzi-Jinshan-Xiaozhuang ductile brittle shear zone in north Qixia city,which is closely associated with basic vein rock in Mesozoic era.The fluid inclusions show that the ore-forming fluids are of low salinity and low-density NaCl-H2O-CO2 system characterized by rich CO2 in the early stage of mineralization.But after boiling action,it later becomes to be NaCl-H2O system formed at 2.33-3.00 km below the surface with a temperature of 165-280 ℃ .Isotope studies show that the ore-forming fluids is mainly from magmatic water in the early stage of mineralization and much meteoric water were mixed into the ore forming system during the late stage,metallogenic materials originate from dikes of Mesozoic,and also from palanobasement of Jiaodong.Changes of Physical and chemical properties caused by boiling action and mixture of atmospheric precipitation is main metallogenic mechanism.