摘要
大兴安岭地区矿产资源十分丰富,是我国重点勘查区之一,区内已经探明的矿床点200多处,其多与中生代岩浆活动有关,近年来有研究证明林西组底部存在海相沉积,通过地质调查、剖面测制、层序调查、粒度分析、矿物鉴定等综合研究,并通过碳酸盐、稀土光谱、微量元素等分析古环境,认为林西组沉积环境早期为海陆交互相环境,中晚期为河湖相环境。通过资料分析大兴安岭地区矿化带中存在三个比较大的沉积中心,以林西一带为南部沉积中心,以兴安盟大石寨~索伦一带为中部沉积中心,以呼伦贝尔盟阿荣旗~巴林一带为北部沉积中心。本区位于中部沉积中心,其特征是地层厚度较大,沉积构造较好,含丰富的植物化石和双壳类化石,尤其在底部出现一套碎屑岩夹碳酸岩(核形石灰岩)的组合,更加完善了林西组层序的完整性,该矿区林西组一段发现了4层形成于碳酸盐台地边缘的核形矿物,为东北地区的首次发现,具有重要的地质意义。
The Daxing'anling area is rich in mineral resources and is one of the key exploration areas in China. There are more than 200 proven ore deposits in the area, which are mostly related to Mesozoic magmatic activities. In recent years, studies have proved that there are marine deposits at the bottom of Linxi Formation. Through comprehensive studies such as geological survey, profiling, sequence investigation, grain size analysis, mineral identification, and through carbonate and rare earth spectroscopy. Based on the analysis of palaeoenvironments by trace elements, it is concluded that the sedimentary environment of Linxi Formation is marine-continental interfacies in the early stage and river-lake facies in the middle and late stage. According to the data analysis, there are three relatively large sedimentary centers in the mineralization zone of Daxing'an Mountains, with Linxi area as the southern sedimentary center, Dashizhai-Solun area of Xing'an League as the central sedimentary center, and Arong Banner-Bahrain area of Hulunbeir League as the northern sedimentary center. Located in the central sedimentary center, this area is characterized by large stratum thickness, good sedimentary structure, abundant plant fossils and bivalves, especially a combination of clastic rocks with carbonate rocks (karyotypic limestone) at the bottom, which further improves the sequence integrity of Linxi Formation. Four layers of karyotypic minerals formed on the margin of carbonate platform were found in the first member of Linxi Formation in this mining area, which is east. The first discovery in North China has important geological significance.
作者
丁伟
DING Wei(Liaoning Provincial Geological Exploration Institute,Dalian 116100,China)
出处
《世界有色金属》
2019年第6期195-200,共6页
World Nonferrous Metals
关键词
大兴安岭
成矿带
地质特征
沉积环境
Daxing'an Mountains
Metallogenic Belt
Geological Characteristics
Sedimentary Environment
