新疆西天山查岗诺尔铁矿含矿地层特征研究

发布时间：2018-05-06 07:13

本文选题：西天山 + 大哈拉军山组　；参考：《长安大学》2015年硕士论文

【摘要】：新疆西天山查岗诺尔铁矿是近年来在西天山阿吾拉勒成矿带发现的亿砘级铁矿之一,本文依托“西天山阿吾拉勒铁矿带铁矿成矿机理与控矿因素研究”项目,开展查岗诺尔铁矿含矿地层特征研究,对查明含矿地层形成时代,成矿地质背景,以及成矿预测具有重要的理论意义和实际意义。在广泛收集前人资料的基础上,开展了大量野外地质工作路线调查、实测地层剖面和室内综合研究工作,重点依据含矿地层的岩石组合特征、古生物化石特征、同位素年龄等资料,对查岗诺尔铁矿的含矿地层特征,包括其岩性组合、古生物化石组合、火山岩建造的喷发韵律、同位素年龄等进行了系统研究,并结合区域地层资料进行了地层对比。取得了如下认识:1、通过对查岗诺尔矿区地质剖面测制及详细的地质调查工作,查明了研究区的含矿地层为石炭系大哈拉军山组,为一套以中酸性火山碎屑岩为主的滨-浅海相火山岩建造,据岩性组合可将其划分为上、下两个岩性段,可分别与区域大哈拉军山组的第一、第二岩性段对比。铁矿主要赋存在大哈拉军山组第二岩性段。2、对矿区含矿地层大哈拉军山组火山岩的分布、规模、喷发韵律、喷发旋回进行了系统研究,发现第一岩性段和第二岩性段分别构成了两个火山喷发旋回。下段为第一喷发旋回,由3-4个火山喷发次组成,单个喷发次在100-400米之间变化。其喷发组合序列为:火山角砾岩—凝灰岩;或火山熔岩—凝灰岩;或火山角砾岩—火山熔岩—凝灰岩。上段为第二旋回,由4-6个喷发次组成,单个喷发次百100-500米不等。其喷发岩序列为:含火山角砾凝灰岩—凝灰岩;火山集块岩—角砾凝灰岩—凝灰岩;熔岩—凝灰岩。表明火山岩形成的环境为晚古生代裂谷的滨浅海喷发环境。3、依据本次在查岗诺尔铁矿区含矿地层大哈拉军山组灰岩夹层中采到的珊瑚、腕足和海百合茎等化石,包括:Caninophyllum sp.(似犬齿珊瑚)、Dibunophyllum sp.(棚珊瑚)、Gigantoproductus sp.(大长身贝)、Linoproductus sp.(纹线长身贝)和Cyclocyclicns sp.(圆海百合茎)等,以及从本组流纹岩中获得锆石U-Pb年龄321.2±2.3Ma的数据,确定查岗诺尔铁矿含矿地层大哈拉军山组的地质时代为早石炭世的杜内期-维宪期。
[Abstract]:Chagang Noor Iron Mine in West Tianshan, Xinjiang, is one of the hundred million tons iron ore found in the Awulale metallogenic belt of West Tianshan in recent years. This paper relies on the project of "study on the metallogenic mechanism and ore-controlling factors of iron ore in the Awulale iron ore belt of West Tianshan Mountain". It is of great theoretical and practical significance to study the characteristics of ore-bearing strata in Chagannuoer Iron Mine in order to find out the forming age of ore-bearing strata, metallogenic geological background and metallogenic prediction. Based on the extensive collection of previous data, a large number of field geological work route surveys, measured stratigraphic profiles and laboratory comprehensive studies have been carried out, with emphasis on the characteristics of rock assemblages and paleontological fossils of ore-bearing strata. The characteristics of ore-bearing strata, including lithologic assemblage, fossil assemblage of paleontology, eruption rhythm of volcanic rock formation, isotopic age and so on, are systematically studied in this paper. Combined with regional stratigraphic data, stratigraphic correlation is carried out. We have obtained the following understanding: 1. Through the geological profiling and detailed geological investigation in Chagang Noor mining area, we have found out that the ore-bearing strata in the study area are the Carboniferous Dahala Junshan formation. It is a suite of shore-shallow marine volcanic rocks mainly composed of intermediate-acid pyroclastic rocks, which can be divided into upper and lower lithologic segments according to lithological assemblages, and can be compared with the first and second lithologic formations of the regional Dahara Junshan formation. The distribution, scale, rhythm and cycle of the volcanic rocks in the ore-bearing strata of the Dahala Junshan formation are systematically studied in the second lithologic section of the Dahala Junshan formation, the second lithologic section of the Dahala Junshan formation. It is found that the first lithologic segment and the second lithologic section constitute two volcanic eruptive cycles respectively. The lower part is the first eruption cycle, which consists of 3-4 volcanic eruptions, with individual eruptions varying between 100 and 400 meters. The eruption assemblage sequence is: volcanic breccia-tuff; or volcanic lava-tuff; or volcanic breccia-volcanic lava-tuff. The upper segment is the second cycle, consisting of 4-6 eruptions, with a single eruption of 100-500 meters. Its eruptive rock sequence is: volcanic breccia tuff-tuff; volcanic agglomerate-breccia tuff-tuff; lava-tuff-tuff. The results indicate that the volcanic rocks were formed in the late Paleozoic rift shoreline eruption environment. 3. According to the fossils of coral, brachiopod and sea lily stem collected from the limestone intercalation of the ore-bearing strata of Dahalajunshan formation in the Chagonauer iron ore area, including the: Caninophyllum sp. Dibunophyllum sp. (Gigantoproductus sp. Linoproductus sp. (Pinctada serrata) and Cyclocyclicns sp. The data of zircon U-Pb age of 321.2 卤2.3Ma obtained from the rhyolite, et al., indicate that the geological epoch of the ore-bearing strata of Chagannuoer iron deposit is Dune period and Weixian period of early Carboniferous.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.31

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