粤西云开岩群的建立──云开地区前泥盆纪变质地层的再认识

Establishment of the Yunkai Group-complex in western Guangdong：A new understanding of pre-Devonian metamorphic strata in the Yunkai area

根据最新1∶5万区域地质调查成果，认为粤西云开地区前泥盆纪变质地层属一套总体有序、局部无序的构造地层单位系统，因此建议新建云开岩群。依据叠覆关系，又将其划分为新垌岩组、帅堂岩组、山美岩组、清垌岩组4个岩组。各岩组间以顺层韧性剪切变形带为界面，空间分布主要受第一期北西向褶皱控制。云开岩群适用于整个粤西云开地区，前人所建立的"云开群"及"高州岩群"实为同一套岩层，即云开岩群。

： Through recent 1∶50000 regional geological mapping in the Yunkai area， western Guangdong， the authors think that pre-Devonian metamorphic rocks in the Yunkai area is a tectono-stratigraphic unit system which is ordered in general but disordered in part． Based on the regional superimposition relationships the Yunkai Group-complex may be further divided into the Xindong， Shuaitang， Shanmei and Qingdong formation-complexes． The four formation-complexes are separated by bedding-parallel ductile shear zones and the first-phase NW-trending folds control their distribution．The Yunkai Group-complex is suited for the whole Yunkai area， western Guangdong． The Yunkai Group and Gaozhou Group-complex is actually the same tectono-stratigrphic unit， i．e． the Yunkai Group-complex．