一、前言 霍邱群分布于霍邱县西,四十里长山东麓,向北延经吴集、草楼、周集,越过淮河至颖上陶坎、汪坝等地,近南北向延展。经较多的钾氩法同位素年龄测定,其年龄为17亿年左右(铷锶法测定大于20亿年)。 霍邱群为一套中深变质的角闪斜长片麻岩、硅线、蓝晶黑云片岩、黑云变粒岩、大理岩等,自下而上,可划为四个组。 I. Introduction Huoqiu group is located in the west of Huoqiu County, 40 miles long mountain east of Lu, northward extension of Wuji, Cao Lou, Zhouji, across the Huaihe Ying Ying Taokan, Wangba and other places, near the north-south extension . After more potassium and argon isotope dating, its age is about 1.7 billion years (rubidium strontium method for the determination of more than 2 billion years). Huo Qiuqun is a set of middle-metamorphic hornblende plagioclase gneiss, silicon line, blue crystal black rock schist, black cloud granulite, marble, etc., from bottom to top, can be divided into four groups.