甘肃阳山金矿地质地球化学找矿模型

发布时间：2018-06-13 17:22

本文选题：阳山金矿 + 地球化学找矿模型　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：阳山金矿带地处甘肃省南部,属“川陕甘金三角”区,而且阳山金矿是全国近期发现规模最大的金矿。研究并建立阳山金矿地质地球化学找矿模型具有重要意义,可以为我国金矿资源勘查和川陕甘地区及周边找矿预测提供借鉴。本文在收集阳山金矿床地质资料和区域岩石、矿区岩石、区域水系沉积物化探数据的基础上,研究矿床的地质特征、地球化学异常特征,同时初步研究了阳山金矿区岩石风化过程中微量元素的定量变化,建立了阳山金矿的地质-地球化学找矿模型。主要得出以下结论:甘肃阳山金矿床为一超大型矿床,位于陇南市文县境内,矿体呈出露状态。赋矿地层主要为泥盆系三河口群千枚岩。成矿与区内花岗斑岩脉有关系密切,花岗斑岩成岩年龄约200±9Ma。金矿体受安昌河-观音坝断裂控制,主要赋存于次级剪切带或断裂中。矿石类型主要为蚀变千枚岩型和蚀变斜长花岗斑岩脉型,矿体形态呈脉状。围岩蚀变主要以硅化、绢云母化、碳酸盐化、黄铁矿化为主。阳山金矿区花岗斑岩类岩石与中国花岗岩相比,明显相对富集Al2O3和Ca O,其富集系数为1.15和1.26。阳山金矿区蚀变斜长花岗斑岩与阳山斜长花岗斑岩相比,在微量元素方面富集系数大于2.5的元素有Au、Co、Sb;即蚀变或成矿过程相对富集Au、Co、Sb。区域水系沉积物化探研究显示,相对于中国水系沉积物而言,阳山金矿区水系沉积物中明显富集Au、Sb、Hg、Cd,富集系数均大于2.5,其中Au的富集系数为2.84。结合元素地球化学异常剖析图,结果表明该矿区金矿成矿指示元素组合为Au、As、Sb、Hg、Cd、Ba、Li计7项元素。依据定量刻画风化过程中微量元素行为的经验方程对阳山矿区岩石在风化过程中元素的定量研究,表现出不相容元素中Li、Be、F在矿区出现富集,热液成矿元素中Bi、Cd、As、Sb、Hg计5项元素整体表现出正异常。前面通过区域岩石地球化学特征和地球化学剖析图确定的成矿指示元素组合Au、Sb、Hg、Cd、Ba、Li、As。基于上述研究建立了甘肃阳山金矿地质地球化学找矿模型。
[Abstract]:Yangshan gold belt, located in the south of Gansu Province, belongs to the "Sichuan, Shaanxi and Gansu Golden Triangle", and Yangshan Gold Mine is the largest gold deposit recently discovered in China. It is of great significance to study and establish the geological and geochemical prospecting model of Yangshan gold deposit, which can be used as a reference for the exploration of gold resources in China and the prospecting prediction in and around Sichuan, Shaanxi and Gansu. Based on the geological data of the Yangshan gold deposit and the geochemical exploration data of regional rocks, rocks and regional drainage sediments, the geological characteristics and geochemical anomalies of the deposits are studied in this paper. At the same time, the quantitative change of trace elements in the weathering process of rock in Yangshan gold deposit is studied, and the geological geochemical prospecting model of Yangshan gold deposit is established. The main conclusions are as follows: the Yangshan gold deposit in Gansu Province is a super large deposit located in Wenxian County of Longnan City and the orebody is exposed. The ore-bearing strata are mainly phyllite of the Devonian Sanhekou Group. The mineralization is closely related to the granitic porphyry vein in the area, and the diagenetic age of the granitic porphyry is about 200 卤9 Ma. The gold orebody is controlled by the Anchang-Guanyinba fault and mainly occurs in the secondary shear zone or fault. The ore types are mainly altered phyllite type and altered long granitic porphyry vein type. The main alteration of surrounding rock is silicification, sericite, carbonization and pyrite. The granitic porphyry rocks in Yangshan gold deposit are obviously enriched in Al _ 2O _ 3 and Ca _ 2O as compared with the granites in China, and their enrichment coefficients are 1.15 and 1.26 respectively. Compared with Yangshan plagioclase granitic porphyry in Yangshan gold deposit, the elements with enrichment coefficient greater than 2.5 in trace elements are Au-CoCoSb, that is, au CoCoSb is relatively enriched in alteration or metallogenic process. The geochemical study on the sediments of the regional drainage system shows that, compared with the sediments of the water system of China, the gold deposits of Yangshan gold deposit are obviously enriched in the sediments of the water system of the Yangshan Gold Mine, and the enrichment coefficients of au are all greater than 2.5, and the enrichment coefficient of au is 2.84. Combined with the analysis of geochemical anomalies of elements, the results show that the metallogenic indicator element assemblage of gold deposit in this area is 7 elements. Based on the empirical equation of quantitative characterization of trace element behavior in weathering process, the quantitative study of elements in rock weathering process in Yangshan mining area shows that the incompatible elements of Li-BeBeF are enriched in the mining area. In the hydrothermal metallogenic elements, the total positive anomalies of the five elements of the BigCdCd-As-Sb-Hg have been observed. The metallogenic indicator element assemblage determined by the geochemical characteristics of regional rocks and geochemical analysis map in the first place is the Auto-SbSbHgcdcdcdcdcdcdcdcdcdcdcdcdcdb@@ Based on the above study, a geological and geochemical prospecting model of Yangshan gold deposit was established.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.51

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