江苏小梅岭硅灰石矿床特征及其成因

江苏溧阳小梅岭硅灰石矿产于二叠系栖霞组硅质岩中，其成矿热液主要来自庙西花岩岩体。矿体以层状产出，矿石为不规则透镜体，方解石和硅灰石常常互层，常见有硅质岩核心。伴生矿物主要有透辉石、绿帘石、符山石、鱼眼石和萤石。根据x射线衍射分析研究，矿区内硅灰石均属三斜低温硅灰石，其a=-7．934，B0＝7．321，C0=7．068，红外光谱和差热分析表明，该硅灰石矿杂质含量较少。根据野外地质条件和理论反应式、反应曲线，小梅岭硅灰石矿形成于半封闭的体系，其形成温度和压力均属中等。

CHARACTERISTICS AND ORIGIN OF THE XIAOMEILING WOLLASTONITE DEPOSIT,JIANGSU PROVINCE

The wollastonite deposit in Liyang county, Jiangsu province, occurs in siliceous limestone of the Qixia formation of Permian The Miaoxi granite supplied the heat which is needed for wollastonite forming. The orebodies oeeur in beds and irregular lenticles. Calcite and wollastonite exist in interbeds. The siliceous cores are often found in the wollastonite ores. The associnted minerals are diopside, epidote, vesuhanite, apophyllite and fluorite. According to X-Ray diffraction analysis, the wollastonite in this mine is a triclinic epithermal one, crystal cell paraxneters of which are a0= 7. 934,b0= 7. 321 and c0= 7. 068. The LAS and DTA show a little impurities existing in wollastonite ores. Based on geological conditions in field, the theoretital reaction formuta and the reaction curves, the wollastonite deposit in Xiaomeiling formed in a semi-confining system with middle ore-forming temperature and pressure.