A Study on the Tectonic Basement of Late Mesozoic Igneous Rocks in Southeastern China

摘要: According to middle high grade metamorphic rock assemblages, structural deformational styles and newer data of isotopic ages, this paper suggests that a Precambrian continental block existed in the southern Zhejiang-northern Fujian-central Jiangxi-eastern Guangdong region, South China. This oldland, with oldest age 2100 Ma named Cathaysian Oldland, is characterized by large scale development schist, gneiss migmatic rocks interval from 1800Ma 1200 Ma, which comprise crustal basement. About 1100～900Ma, Oldland collided Yangzi plate form Shaoxing-Jiangshan-Dongxiang-Pingxiang Fault Zone. Not long time later, about 800 was dispersed into three blocks different strikes distinct outline, is, NEE striking Southeastern Zhejiang-Northwestern Fujian Block, sub N S Central Jiangxi-Southern Jiangxi Block NE Yunkaidashan respectively. The Sinian-Early Paleozoic sedimentary materials thickness filled among these blocks. Study proposes oldland subjected phase tectonic thermal events at least, Luliang event (1800 1600Mha), Jinning (1100 900Ma) Caledonian (420 400Ma) since Neo Proterozoic become basement Late Mesozoic (mainly Cretaceous) volcanic intrusive complexes. feature Coastal Region not clear due lack outcropped data. But according geochronological 1806Ma whole Rb Sr method on core gneissic Linfeng hole N0.1 East China Sea (East Wenzhou), we guess should exist under Meso-Cenozoic Sea. During Mesozoic-Paleogene, intra rift basin formed along Zone, red bed filled. ancient framework constrains tectonics magmatism difference magmatic compositions distributrion.