重庆市城口锰矿矿体空间赋存规律及找矿预测

Orebody Spatial Occurrence Regularity and Prospecting Prediction of Chengkou Manganese Mine in Chongqing City

城口锰矿床为沉积型矿床,自2015年开展整装勘查工作以来,由于对锰矿体的空间赋存规律研究不足,严重制约了钻孔见矿效果,无法实现重大找矿突破。为此,通过综合分析城口锰矿以往研究成果及矿产勘查资料,对矿体空间赋存规律进行了研究。结果表明:(1)锰矿体空间赋存受地层、沉积环境和成矿后期破矿构造3个因素影响;(2)锰矿体的赋存地层为震旦系下统陡山沱组二段顶部,形成于从酸性向碱性转化的还原沉积环境中;(3)台缘斜坡—局限台地(泻湖)相为锰矿发育的主要相带,局限台地(潮下)次之;(4)矿区发育的断层和褶皱均为成矿后期破矿构造,构造形态与矿体在深部的展布形态一致。根据上述分析,圈定了3处找矿靶区,其中,(1)号靶区最具有找矿潜力,(2)、(3)号靶区找矿潜力次之。

Chengkou manganese deposit is a sedimentary deposit. Due to the lack of study on the spatial occurrence of manganese orebodies, the drilling effects is restricted seriously, and a major prospec- ting breakthrough can not be achieved,since the integTated exploration work is carried out in 2015. In or- der to solve this problem, through the study of the past analysis results and mineral exploration data of Chengkou manganese deposit, the orebody spatial occurrence regularity of the deposit are analyzed. The study results show that：①the spatial occurrence of manganese orebodies are affected by three factors,in- eluding stratigraphy,sedimentary environment and ore-breaking structure after metallogenic period ; ②the manganese orebodies occur at the top of the second member of the Doushantuo Formation of Lower Sini- an,formed in the reductive sedimentary environment from acidic to alkaline transformation ; ③the platform margin slope and the restricted platform （lagoon） facies are the main facies for the development of man- ganese orebodies,and the restricted platform （subtidal） facie is a secondal7 important facie for manga- nese orebodies ;④faults and folds in the mining area are all ore-breaking structures after metallogenic pe- riod, and the structural forms is consistent with the distribution of the orebodies in deep area. According to the above study results,three prospecting targets ares are delineated,the No. 1 target area is the most im- portant prospecting potential area and the others are the secondary important prospecting potential areas.