内蒙古腮林忽洞群综合地层和白云鄂博矿床赋矿微晶丘  

COMPOSITE STRATIGRAPHY OF THE SAILINHUODONG GROUP AND ORE-BEARING MICRITE MOUND IN THE BAYAN OBO DEPOSIT, INNER MONGOLIA, CHINA

作　　者：乔秀夫[1] 高林志[1] 彭阳[1] 章雨旭[2] 

机构地区：[1]中国地质科学院地质研究所 [2]中国地质科学院

出　　处：《地质学报》1997年第3期202-211,T002,共11页Acta Geologica Sinica

基　　金：国家自然科学基金(编号4962008);国家基础性重大研究项目(SSLC)

摘　　要：据层序地层、事件地层、生物地层和岩石地层研究.腮林忽洞群是白云鄂博群的一部分。于腮林忽洞群下部层位的岩石切片中首次发现三叶虫屑,并首次分离出奥陶系疑源类及几丁虫化石;于上部层位首次识别出碳酸盐震积岩组及顶部巨型微晶丘(micrite mound)。白云鄂博超大型铌稀土铁矿赋矿白云岩既非火成碳酸岩,也非一般层状沉积岩,而是一巨型微晶丘,与腮林忽洞群顶部微晶丘白云岩宏观特征一致,并可能属同一层位。根据已有的化石材料,腮林忽洞群与白云鄂博群应为下古生界而非中元古界。本文的新发现与新认识将对白云鄂博超大型矿床的成因解释提供新的思路。并有可能在其以南地区发现新的同类型矿床。Based on studies on sequeence stratigraphy, event stratigraphy, biostratigraphy and lithos-tratigraphy, it is concluded that the Sailinhuodong Group is a part of the Bayan Obo Group. Some fragments of trilobites are first found in thin sections of the rock from the lower part of the Sail-inhuodong Group and some Ordovician acritarch and chintinozoans are also found in this group. A series units of carbonate seismites are first recognized in the upper part and a huge micrite mound at the top. Dolomite bearing the super-giant Bayan Obo iron-niobiumn-rear-earth deposit is neither igneous carbonatite nor common bedded sedimentary carbonate, but a huge micrite mound. It has the same macroscopic characters as the micrite mound at the top of Sailinhuodong Group, which suggests that they should be the same horizon. According to the fossils, the age of the Sailinhuodong Group and Bayan Obo Group is Early Palaeozoic, rather than middle Protero-zoic. The new discovery and new idea will throw light on the explanation of the genesis of the super-giant Bayan Obo Iron-Niobium-rear-earth deposit.

关 键 词：腮林忽洞群 多金属矿床 震积岩 微晶丘 赋矿 

分 类 号：P536[天文地球—古生物学与地层学] P618.202[天文地球—地质学]