中国东南部中、新生代盆地特征与构造演化

Geological features and tectonic evolution of Meso-Cenozoic basins in southeastern China

中国东南部中、新生代盆地与花岗岩构成了复杂的盆岭镶嵌体系———华南盆岭构造。根据盆地的几何学、运动学、动力学与构造演化特征,将研究区中、新生代盆地划分为类前陆盆地、裂谷盆地和断陷盆地三大类型。对晚三叠世以来各个时代盆地的规模、产状、边界、岩石组合、指相矿物、沉积构造进行了分析。不同时代盆地的特征和重点区段盆区岩层的节理测量-统计结果表明,晚三叠世以来研究区的盆-岭格局至少经历过4期地球动力学演化。该盆-岭体系具有密切的时空和成因联系,二者时间相近,空间相伴,成因相关。研究表明,永定-龙南-始兴是一个中侏罗世陆内裂谷带,武夷山是晚中生代的古地理与气候分隔带,赣江带是晚中生代的火山岩界线。

Meso-Cenozoic basins and granites in southeastern China form a complex basin-range mosaic pattern-the South China basin-range tectonics. According to the geometric, kinematic and dynamic features and features of tectonic evolution of the basins, Meso-Cenozoic basins are divided into three types, namely foreland basin, rift basin and downfaulted basin. Analysis is made of the sizes, attitudes, boundaries, rock associations, sedimentary structures and diagnostic minerals of the basins of various ages since the Triassic. The characteristics of basins of various ages and measurements and statistics of the joints in the strata of the basins in major areas indicate that the basin-range pattern in the study area at least underwent four phases of geodynamic evolution since the Late Triassic. This Meso-Cenozoic basins and granite bodies have close tempo-spatial and genetic relations; i.e. they occurred approximately at the same time and are spatially and genetically associated. Study suggests that the Yongding-Longnan-Shixing basin is a Middle Jurassic intracontinental rift zone, the Wuyi Mountains are a Late Mesozoic paleogeographic and paleoclimate boundary, and the Ganjiang River fault is a western boundary of the Late Mesozoic volcanic zone. On that basis, southeastern China is divided into three Meso-Cenozoic tectono-magmatic-sedimentary regions.