宁镇中段矽卡岩型矿床的闪锌矿及其地质压力计应用讨论  

Genetic mineralogical properties of sphalerite and discussions on its geobarometer application in skarn ore deposits in middle Ningzhen region

作　　者：丁存根[1] 张术根[2] 马春[1] 徐忠发[1] 

机构地区：[1]江苏省有色金属华东地质勘查局地质矿产勘查开发院,江苏南京210007 [2]中南大学地学与环境工程学院,湖南长沙410083

出　　处：《地质学刊》2009年第2期124-129,共6页Journal of Geology

摘　　要：宁镇山脉中段矽卡岩型铁铜矿床的成矿深度是该地区深部找矿前景分析的重要参考因素,以往多运用地质分析法来定性讨论。通过野外调查,发现这些矿床常有少量闪锌矿伴生。初步研究了该地区伏牛山铜矿、安基山铜矿、团山硫铁矿、盘龙岗铁铜矿以及胄王村多金属矿等代表性矿床(点)所伴生闪锌矿的产出特征、矿物共生组合、常量化学成分及晶体结构,发现该区闪锌矿形成于热液硫化物阶段的中晚期,部分矿区具有至少两个结晶世代,无论其共生矿物、结晶形态、颜色、成分或晶体结构均随产状和矿物共生组合有规律地变化。只有团山硫铁矿和伏牛山铜矿的第一世代闪锌矿与六方磁黄铁矿及黄铁矿平衡共存,符合闪锌矿地质压力计应用条件,用前人修正的闪锌矿压力计获得的成矿压力与地质分析结论吻合,为0.9kPa^1.2kPa,相当于成矿深度2 420m^3 630m,比照处在相同成矿带的湖北大冶和安徽铜陵深部找矿结果,认为该区仍有深部找矿前景。The ore-forming depth was a highly concerned factor for the predication of potential ore reserves of skarn Fe-Cu deposits in the middle Nanjing-Zhenjiang granite province, and was only estimated qualitatively by geological methods before. Sphalerite was found in these deposits as minor components and the authors preliminarily studied the properties in occurrence, paragenesis, basic chemical compositions as well as crystal structure of the minerals from representative mines of Funiushan （Cu） ,Anjishan （Cu） ,Tuanshan （S）, Panlonggang （Fe-Cu） and Zhouwangcun （polymetallic）. According to the occurrence and paragnosis, sphalerite was precipitated during the medium to terminal hydrothermal sulfide stage and two generations were present at least in some of these mines. The apparent color, morphology, crystalline habit, basic chemical composition and crystal structure of sphalerite are all varied regularly with the occurrence and paragenesis. Only the first generation sphalerite with dark brown color at Tuanshan and Funiushan mine was in equilibrium with pyrite and hexagonal pyrrohotite and met the demand of geobarometer application. The pressure calculated from the revised equa- tion of sphalerite barometer was between 0.9 kPa and 1.2 kPa, equivalently to be the depth between 2.42km and 3.63 km, in a good accordance with the estimation from geological method. In reference to the recent achievement in deep prospecting in Daye, Hubei and Tongling,Anhui that was in the same metallogenetic belt with the middle Nanjing-Zhenjiang granite province the deep prospecting potential should be positive in this region.

关 键 词：闪锌矿 地质压力计 矽卡岩型矿床 宁镇山脉中段 江苏 

分 类 号：P578.23[天文地球—矿物学] P588.312[天文地球—地质学]