Late Proterozoic Colisional Orogen and Geosuture in Southeastern China:Petrological Evidence

The Jiangshan-Shaoxing fracture belt(JSFB)is a Late Proterozoic geosuture due to island arc-continent collision in South China,The Cathaysian Block(CT),lying on the southeast side of JSFB,is composed of green schist-amphibolite complexes in the form of a series of tectonic flakes. On the northwest side of JSFB,which is located in the border area of Zheijiang,Jiangxi and Ahhhi provinces(abbreviated as ZJP-JXP-AHP),are distrbuted and ophiolite suite and other rocks,constituting the Jiangnan ancient island arc(JN)on the southeast margin of the Yangtze Block(YZ).The collision between JN and CT at-0.9Ga ago led to the folding of JN.followed by the intrusion(-0.9-0.8Ga ago)of many dioritic and ultramafic stitching plutons along the fracture belt.As a result,the basic Precambrian tectonic framework of southeastern China was shaped.

The Jiangshan-Shaoxing fracture belt(JSFB)is a Late Proterozoic geosuture due to island arc-continent collision in South China.The Cathaysian Block(CT),lying on the southeast side of JSFB,is composed of green schist-amphibolite complexes in the form of a series of tectonic flakes. On the northwest side of JSFB,which is located in the border area of Zhejiang,Jiangxi and Anhhi provinces(abbreviated as ZJP-JXP-AHP),are distributed an ophiolite suite and other rocks, constituting the Jiangnan ancient island arc(JN)on the southeast margin of the Yangtze Block(Y Z).The collision between JN and CT at～0.9Ga ago led to the folding of JN,followed by the intrusion(～0.9-0.8Ga ago)of many dioritic and ultramafic stitching plutons along the fracture belt.As a result,the basic Precambrian tectonic framework of southeastern China was shaped.