重庆城口地区陡山沱组层序地层及锰矿控矿研究

发布时间：2018-06-26 21:03

本文选题：层序地层 + 锰矿　；参考：《成都理工大学》2015年硕士论文

【摘要】：锰矿作为我国重要战略性矿产资源,在国民经济中占有极其重要的地位。锰是钢铁产业必不可少的原料之一。重庆市锰矿资源,主要分布在秀山和城口地区,随着两地资源加工型产业迅速发展,锰工业己成为两县经济发展的支柱产业。伴随着地方经济的快速发展,锰矿资源的消耗也逐年递增,可采资源量不断减低且老矿山开采能力的逐渐下降,现有的锰矿资源难以满足市场需求,产需矛盾日渐突出。为满足地方经济发展对矿产资源的需求,一方面需要提高锰矿深加工程度；另一方面,更重要的是创新锰矿找矿方法、找矿思路,重点加强对重庆市锰矿成矿条件、控矿规律的研究,以先进的找矿理论指导锰矿勘查工作,尤其是深部锰矿勘查工作。城口地区陡山沱组的锰矿主要集中在该组上部,层控特点十分明显,然而对于该区锰矿形成至关重要的沉积因素,尤其是从岩相古地理、沉积建造、构造控矿等方面的大比例的深入研究则较少。本文以重庆市城口地区的典型矿区为研究对象,通过踏勘、剖面测制、岩心观察、矿洞观测等野外地质手段,以赋矿层位陡山沱组为研究对象,并且结合收集到的剖面资料,重点研究该区陡山沱组的沉积层序特征、层序划分及层序地层格架,在此基础上进一步结合陡山沱组的岩石地球化学特征探讨其对锰矿的控矿机制。取得以下认识：1、通过野外露头层序地层学的研究可以识别出四种典型的界面：平行不整合面、暴露面、岩性岩相转换面、地层叠置结构转换面。综合研究表明,震旦系自下而上可划分出6个中期层序,即三级沉积层序单元,分别记为ZOS0-ZOS5;2个长期层序ZSS1、ZSS2。2、由于岩性、构造特征等差异,元素地球化学特征在纵向分布上存在较大变化；轻稀土相对重稀土在总量上明显富集,Ce、Eu显示明显的负异常；微量元素结果指示了该区陡山沱组总体上一种贫氧一缺氧的环境,且沉积物形成过程中有热水的注入。3、当海水上升至海平面达到最大值时,在陡山沱组上部形成了最大海泛期的以磷锰矿层为典型特征的凝缩层,也即赋存在陡山沱中的磷锰矿。虽然城口地区陡山沱组顶部地层是磷锰矿的赋矿层位,但由于地势差异,不同地段含锰层位会有所差异,有的地区甚至没有锰矿层的产出,在空间上自北西向南东有逐渐升高的趋势。
[Abstract]:As an important strategic mineral resource in China, manganese ore occupies an extremely important position in the national economy. Manganese is one of the essential raw materials in iron and steel industry. The manganese ore resources in Chongqing are mainly distributed in Xiushan and Chengkou areas. With the rapid development of resources processing industry in both cities, manganese industry has become the pillar industry in the economic development of the two counties. With the rapid development of local economy, the consumption of manganese resources is increasing year by year, the quantity of recoverable resources is decreasing and the mining capacity of old mines is decreasing gradually. The existing manganese resources are difficult to meet the market demand, and the contradiction between production and demand is becoming more and more prominent. In order to meet the demand of local economic development for mineral resources, on the one hand, it is necessary to improve the degree of further processing of manganese ore; on the other hand, it is more important to innovate the prospecting method and train of thought of manganese ore prospecting, with emphasis on strengthening the conditions of manganese mineralization in Chongqing. The study of ore control law guides the exploration of manganese deposits, especially the exploration of deep manganese deposits, with advanced prospecting theory. The manganese deposits of the Doushantuo formation in Chengkou area are mainly concentrated in the upper part of the formation, and the stratigraphic characteristics are very obvious. However, the sedimentary factors that are crucial to the formation of manganese deposits in this area, especially from the lithofacies and paleogeography, are the sedimentary formations. A large proportion of the structural ore-control and other aspects of the in-depth study is less. In this paper, the typical mining area in Chengkou area of Chongqing is taken as the research object. Through the field geological means such as exploration, profiling, core observation and cave observation, the Doushantuo formation of the ore-bearing strata is taken as the research object, and the collected profile data are combined. The sedimentary sequence characteristics, sequence division and sequence stratigraphic framework of the Doushantuo formation in this area are emphatically studied. On this basis, the ore-controlling mechanism of the Doushantuo formation on manganese ore is further discussed in combination with the petrogeochemical characteristics of the Doushantuo formation. By the study of outcrop sequence stratigraphy in the field, four typical interfaces can be identified: parallel unconformity surface, exposed surface, lithologic lithofacies transformation surface and stratified structural transformation surface. The comprehensive study shows that the Sinian system can be divided into six intermediate sequences from the bottom to the top, that is, the third-order sedimentary sequence units, which are described as ZOS 0-ZOS 5, and two long-term sequences, ZSS 1 and ZSS 2.2, due to the differences in lithology and structural characteristics, etc. The geochemical characteristics of elements vary greatly in the longitudinal distribution, the relative heavy rare earths of light rare earth show obvious negative anomalies in the total amount of CEE, and the results of trace elements indicate that the Doushantuo formation in this area is an oxygen-poor and anoxic environment in general. In the process of sediment formation, hot water is injected into the sediment. When the sea level rises to the maximum level, the condensed layer, which is characterized by phosphorus and manganese ore, is formed in the upper part of the Doushantuo formation, that is, the phosphorous manganese deposit in Doushantuo. Although the top stratum of Doushantuo formation in Chengkou area is the ore-bearing horizon of phosphorous manganese deposit, because of the difference of topography, the manganese bearing strata in different areas will be different. From north to west to south to east, there is a rising trend in space.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.32;P539.2

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