牛角塘伴生型镉矿床特殊的成矿环境

发布时间：2018-06-30 00:12

本文选题：成矿环境 + 古地理环境　；参考：《吉林大学学报(地球科学版)》2017年02期

【摘要】：牛角塘伴生型镉矿床镉的富集程度高,比克拉克值高4~5个数量级,比工业品位高十几倍至上百倍。早寒武世清虚洞期牛角塘地区处于台缘滩丘环境,在清虚洞组中上部形成了藻丘建造,发育了含藻类、藻球粒、藻鲕粒、核形石和生物碎屑的白云岩,是该矿床最主要的容矿岩性单元。矿体普遍呈似层状、透镜状和脉状产出,矿体产状与容矿围岩的产状基本一致,矿体的分布受清虚洞组藻丘建造以及有利岩性组合的联合控制,具明显的层控、相控、岩控的特点。藻丘建造还可能提供了部分矿源。镉的超常富集、成矿与麻江古油藏的成藏演化具有一定的关系:一是牛角塘矿床成矿年龄为433~510 Ma,即加里东运动的中晚期,而加里东运动中晚期是麻江古油藏的油气活动时期,麻江古油藏的早期演化阶段与牛角塘镉矿的成矿期大体是重合的,成藏应略早于成矿,成矿是在古油藏液态烃仍然存在的情况下进行的,且成矿期有可能一直延伸至油藏被破坏以后;二是油藏流体为成矿提供具还原性质的成矿流体和部分硫源。特殊的岩相古地理环境和古油藏为牛角塘矿床镉的富集和成矿提供了有利条件。
[Abstract]:The enrichment degree of cadmium in Nijiaotang associated cadmium deposit is high, which is 4 ~ 5 orders of magnitude higher than Clark value and 10 to 100 times higher than industrial grade. The Niujiaotang area in the early Cambrian Qingxuxudong period was in the platform margin beach and mound environment. In the middle and upper part of the Qingxudong formation, algal dune formation was formed, and dolomite containing algae, algal globules, algal oolitic grains, nuclear rocks and bioclastic rocks were developed. Is the most important ore-bearing unit of the deposit. The orebodies are generally stratiform, lenticular and vein-like, and the occurrence of orebodies is basically the same as that of the host rock. The distribution of orebodies is controlled by the algal dune formation of Qingxuxudong formation and the favorable lithologic assemblage, which is controlled by obvious stratification and facies control. The characteristics of rock control. Algae-dune construction may also provide part of the mineral resources. The supernormal enrichment of cadmium has a certain relationship with the evolution of Majiang paleoreservoir: first, the metallogenic age of Niujiantang deposit is 433510Ma, that is, the middle and late Caledonian movement is the period of oil and gas activity of Majiang paleoreservoir, and the middle and late Caledonian movement is the period of oil and gas activity in Majiang paleoreservoir. The early evolution stage of Majiang paleoreservoir coincides with the metallogenic stage of Niujiantang cadmium deposit, and the reservoir formation should be slightly earlier than the metallogenic stage, and the mineralization is carried out under the condition that the liquid hydrocarbon still exists in the paleo-reservoir. The ore-forming period may extend until the reservoir is destroyed, and the reservoir fluid can provide the ore-forming fluid and some sulfur source with reductive property for metallogeny. The special lithofacies paleogeographic environment and paleoreservoir provide favorable conditions for cadmium enrichment and mineralization in Niujiantang deposit.
【作者单位】：中国石油辽河油田公司;
【基金】：国家自然科学基金项目(49633110)~~
【分类号】：P618.81

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