GEOLOGICAL FEATURES AND TECTONIC EVOLUTION OF THE MIDDLE PROTEROZOIC LONGQUAN GROUP IN SOUTHERN ZHEJIANG

The Longquan Group is a component part of the Precambrian metamor- phic basement of Zhejiang and Fujian.It is separated from the lower Pro- terozoic Badu Group by a large ductile shear zone and is the volcanic-sedi- mentary product in a tensional fracturing environment.The basal part of this group is represented by a bimodal volcanic formation,the middle part an arenaceous-pelitic clastic formation,and the upper part a clastic-carbonate formation. The main rock types include granulitite,mica schist,epidote-plagio- clase amphibolite,itabirite and marble.The group has undergone regional metamorphism and folding.The general structural configuration is a nearly N-S-trending linear fold system.