辽宁省海城县桦子峪地区中、下元古界再划分

A REDIVISION ON THE LOWER-MIDDLE PROTEROZOIC (LIAOHE GROUP) IN THE HUAZIYU AREA,HAICHENG COUNTY, LIAONING PROVINCE

以构造—地层法为准则进行区域填图,在桦子峪地区发现有三个彼此之间呈不整合接触的构造层。各个构造层分别遭受了不同类型的区域变质作用。据此,将本区的中、下元古界(原辽河群)分解成三套不同的地层—宽甸群、草河群和辽阳群。同位素年代学资料确定它们的主变形变质幕分别发生在2100Ma、1850Ma和1400Ma。

Three structural stages contacting unconformably one another are discovered in regional geological mapping by using the tecto-stratigraphic method. They had undegone different-types of regional metamorphism repectively. Therefore, he Lower-Middle Pro erozoic s rata(previously called Liaohe Group)is redivided into three groups: Kuandian Group,Caohe Group and Liaoyang Group. Their main deforma ional and metamorphic episodes occured in 2100Ma,1850Ma and 1400Ma respectively according to isotopic chronological data.