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 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 R∼ 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.