钦杭结合带加里东期造山运动构造属性探究

A brief review of Geological Structure Attributes of Qin-Hang Belt in Caledon Orogeny

华南包括北西侧扬子板块和南东侧华夏板块,钦(州湾)-杭(州湾)结合带是两板块的巨型构造结合带。它从西南端广西钦州湾,经湘东和赣中延伸到东北端浙江杭州湾地区,全长近2000 km,宽100~150 km,总体呈反S状弧形型展布。新元古代华南经历的古华南洋俯冲消减以及两板块间碰撞拼贴过程,在学界取得了广泛共识。南华纪-早古生代,拼贴的板块拉张-裂解形成盆地,但学者们对盆地的性质认识不一,特别是奥陶纪-志留纪不整合事件的地球动力学过程仍不清楚。主流观点认为陆内造山是加里东造山运动的主要机制,震旦-早古生代的盆地性质为陆内海。还有一些学者认为,大洋板块俯冲是华南加里东期造山运动的主要构造机制,华南存在震旦-早古生代残留洋盆。总之,加里东期造山运动的构造属性存在争议。本文更倾向于后一种观点。

South China including the northwest side of the Yangtze plate and the Southeast of the Cathaysian plate,Qin(Zhou Wan) belt and Hang(Zhou Wan) belt combined with two plates of the mega structure belt.It is from the southwest end of Qinzhou Bay,by the eastern Huna and central Jiangxi extends to the northeast end of the Hangzhou Bay area,length of nearly 2000 km,wide 100- 150 km,overall was reversed S-shaped curved type distribution.Experiencing the Neoproterozoic of South China ancient Nanyang subduction abatement and plate collision process of collage,in the academic community has made broad consensus.Nanhua period and early Paleozoic,spell paste plate pull- cleavage to form a basin,but scholars have different understanding of the basin nature,especially the Ordovician Silurian unconformity event of geodynamic processes remains unclear.Mainstream view within the orogenic is the main mechanism of Caledonian orogeny,Aurora to Early Paleozoic basin is intracontinental sea.Some scholars think the subducting oceanic plate is the main tectonic mechanism of Southern China Caledonian orogeny,Southern China exsit Sinian to Early Paleozoic remnant basin.In a word,the tectonic attribute of Caledonian orogeny have always been controversial.This article is more inclined to the latter view.