江苏溧水爱景山锶矿床天青石矿物形态学与成矿过程的关系

The relation between mineral morphology and metallogenic process of celestite in the Aijingshan strontium deposit in Lishui,Jiangsu Province

江苏溧水爱景山锶矿床位于长江中下游成矿带溧水盆地东段,是我国火山热液型锶矿床的典型代表。文章对该矿床的矿石样品进行了天青石矿物宏观形态学与微观形态学分析,探讨了天青石矿物形态学与成矿过程的关系。研究表明:天青石主要有板状、片状-薄片状、他形细粒状、晶簇状4种宏观形态和板状、细粒状-薄片状、无定型状3种微观形态。该锶矿床的热液成矿过程可分为早期成矿过程和中晚期成矿过程,进一步分为天青石、黄铁矿-天青石、高岭土-天青石和方解石-天青石4个矿化阶段。天青石的矿物形态与矿化阶段相对应,表现为宏观及微观形态中的板状天青石主要形成于早期成矿过程中的天青石和黄铁矿-天青石矿化阶段,其余形态的天青石多数形成于中晚期成矿过程,其中宏观形态中的片状-薄片状、它形粒状和微观形态中的薄片-细粒状多数形成于高岭土-天青石矿化阶段,宏观形态中的晶簇状天青石常形成于方解石-天青石矿化阶段,微观形态中的无定型状天青石在高岭土-天青石矿化阶段和方解石-天青石矿化阶段均可形成。

The Aijingshan strontium deposit in Lishui of Jiangsu Province,located in the eastern section of the Lishui Basin in the middle-lower reaches of Yangtze Basin metallogenic belt,is a representative of volcanic hydrothermal strontium deposits in China.The relation between the morphological characteristics of celestite and its mineralization stages is discussed in the paper by analyzing the macroscopic and microscopic morphology of celestite samples gathered from the strontium deposit.The macro morphological characteristics of celestite main-ly include four forms:tabular,platy-flaky,xenomorphic fine granular and drusy.The microscopic morphology of celestite is characterized with three shapes:tabular,fine granular-flaky and amorphous.The hydrothermal metallo-genesis of the Aijingshan strontium deposit undergone early and mid-late metallogenic processes in sequence,which can be further divided into four stages:celestite,pyrite-celestite,kaolinite-celestite and calcite-celestite.The mineral morphology of celestite corresponds to the metallogenic process,which shows that the tabular celestite in the macro and micro morphology is mainly formed in the celestite and pyrite-celestite mineralization stages dur-ing the early metallogenic process,while the other shapes of celestite are mostly formed during the mid-late pro-cess,i.e.platy-flaky,xenomorphic fine-granular celestite in the macro morphology,and flaky-fine granular ce-lestite in the micro morphology are mostly formed in the kaolinite-celestite mineralization stage,drusy celestite in the macro morphology is formed in the calcite-celestite mineralization stage,while amorphous celestite in the mi-cro morphology can be formed both in the kaolinite-celestite and calcite-celestite mineralization stages.