海南定安某金矿地质物化探特征与找矿方向探讨

发布时间：2018-06-03 07:01

  本文选题：金矿床 + 硫同位素　； 参考：《长安大学》2017年硕士论文

【摘要】：通过野外地质路线、实测剖面、矿井、岩芯等调查研究,室内测试和综合研究,对海南岛中北部定安县某金矿区,从该金矿的矿区地质构造、矿床相关的岩石学、矿物学、稳定同位素及流体包裹体等手段入手,深入研究该金矿的矿床地质特征,探索其成矿物质来源和成矿流体特征,结合该矿区与本次专题研究同时进行的矿区物探、化探调研资料,进行综合研究,总结成矿特征和成矿规律、指出找矿方向。通过多方面综合研究,取得如下研究新认识:1、该区出露地层主要为早白垩世鹿母湾组碎屑岩:岩性主要为含(砾)长石石英杂砂岩,泥质粉砂岩,泥岩等。因沉积物松散、孔隙度大、又夹有钙质层,地层易松动形成层间裂隙,成矿热液沿这类裂隙运移沉淀成矿,使得矿体产状与地层产状近一致。可以,归属于层间滑动破碎带控矿构造类型。因此,造成化探异常与地球物理异常的长轴方向也与地层走向相一致。2、本区出露的早白垩世晚期石英闪长岩(K1γδ)侵位于早白垩世鹿母湾组岩层,其边部与内部有含金矿脉产出,在时间、空间上与金成矿相关。磁异常圈定的隐伏岩体范围与成矿元素化探综合异常多处重合,加上该区硫化物硫同位素数据显示金的成矿物质来主要来自于深部岩浆。所以,该石英闪长岩在时间、空间、及成因上与金成矿密切相关。不仅为成矿提供物质来源,而且为成矿作用提供热源与动力。3、对该金矿石英脉流体包裹体从其岩相学、均一温度、冰点、盐度、密度等进行了详细研究,发现该区主要发育气液两相水溶液包裹体、少量CO2三相包裹体及富气相包裹体。成矿流体具有中低温(均一温度113.9~323.9℃)、低盐度(平均值2.97wt%NaCl)、中密度(平均值0.90 g/cm3)的特征。从而计算出该金矿成矿压力为80.16~235.45×105 Pa,成矿深度为0.27~0.78 km。因此,该金矿为浅成低温热液矿床。4、结合矿区已有的地质物化探资料,大致圈定出了中西部和东南部2处找矿靶区。
[Abstract]:Through investigation and study of field geological route, measured section, mine and core, laboratory test and comprehensive study, the geological structure, petrology and mineralogy related to the gold deposit in a gold deposit area of Dingan County, central and northern Hainan Island, have been studied. By means of stable isotopes and fluid inclusions, the geological characteristics of the gold deposit are studied in depth, the source of the ore-forming material and the ore-forming fluid characteristics are explored, and the geophysical exploration of the ore area, which is carried out at the same time as this special topic study, is combined. Geochemical survey data, comprehensive study, summarized metallogenic characteristics and metallogenic law, and pointed out the direction of prospecting. Through comprehensive research in many aspects, the following new understanding is obtained: the exposed strata in this area are mainly clastic rocks of early Cretaceous Lumuwan formation: lithology is mainly composed of feldspar quartz complex sandstone, argillaceous siltstone, mudstone and so on. Because of loose sediment, large porosity and calcareous layer, the formation is easy to loosen the fracture between cambium, and the ore-forming hydrothermal fluid moves along this kind of fissure to precipitate and form mineralization, which makes the occurrence of orebody close to that of stratigraphic occurrence. Yes, it belongs to the type of ore-controlling structure in the interlayer sliding fracture zone. Therefore, the long axis direction of geochemical anomaly and geophysical anomaly is consistent with stratigraphic strike. The late early Cretaceous quartz diorite (K 1 纬 未) intruded in the early Cretaceous Lumuwan formation, and there were gold bearing veins in its edge and interior. It is related to gold mineralization in time and space. The range of concealed rock bodies delineated by magnetic anomalies coincides with the comprehensive geochemical anomalies of ore-forming elements, and the sulfide sulfur isotope data in this area show that the gold ore-forming materials mainly come from the deep magma. Therefore, the quartz diorite is closely related to gold mineralization in time, space and genesis. Not only to provide material source for metallogeny, but also to provide heat source and power for mineralization. The fluid inclusions of the quartz vein of the gold ore are studied in detail from its petrography, homogenization temperature, freezing point, salinity, density, etc. It is found that there are mainly gas-liquid two-phase aqueous inclusions, a few CO2 three-phase inclusions and gas-rich inclusions. The ore-forming fluid has the characteristics of moderate and low temperature (uniform temperature 113.9t 323.9 鈩，

本文编号：1971916