扬子地台早古生代碳酸盐重力流沉积的地质背景探讨

A DISCUSSION ON GEOLOGIC BACKGROUND FOR CARBONATE GRAVITY FLOWS IN EARLY PALEOZOIC CARBONATE ROCKS ON YANGTZE PLATFORM

扬子地台早古生代碳酸盐重力流分布广,沉积类型多,发育时间长,经历了发生、发展、高峰和衰弱至终止阶段,反映了不同时期构造活动性、碳酸盐台地发育及其斜坡变化情况。重力流分布在文山—江阴深大断裂的东南侧,处在内外大陆架交界的靠外陆架一侧,也就是处在碳酸盐台地前缘斜坡地带,而大陆边缘的大陆坡应向东南方向位移在桂林—茶陵—抚州—江山一线附近,与华南海槽相毗邻。

The carbonate gravity flows in the lower Paleozoic carbonate rocks are distributed on Yangtzi Platform from Southeast Guizhou, East Guizhou, West Hunan to North Jiangxi, South Anhui and Zhejiang. Many types of carbonate rocks were deposited by the carbonate gravity flows for a long period of time, from early Cambrian to early Ordovician. The sedimentation of carbonate by the gravity flows has undergone the initial, developmental, peak and weak stages, which reflect tectonic activity, development of carbonate platform and change of its frontal slope in different time. The carbonate gravity flows were distributed on the southeastern side of Wenshan-Jiangyin deep fault, on the frontal slope at aboundery between the inner and outer shelves of the carbonate platform near the outer shelf. Thus, the continental slope of the shelf (or continental) margin has migrated to southeast, to the southeastern side of the Guilin-Chaling-Fuzhou-Jiangshan line, and was adjacent with Southeast China sea trouch.