【摘要】 江南断裂作为江南隆起带北缘边界的区域性断裂,时空变形特点表现为前燕山期非造山性质的沉积相突变带和燕山期具造山性质的构造变形带。突变带内同生角砾岩仅具相带划分意义。构造变形带内江南断裂中浅层宏观总体表现逆冲断层;地质证据和ESR年龄证据表明断裂作用起始于燕山早期,持续至喜山早期;宏微观构造、包体测温和差异应力等综合研究显示断层总体处于脆性、低温、低差异应力构造变形环境。但江南断裂现今中浅层主要变形形迹和成生条件所表现的构造属性与空间断层性质不相对应,原因可能与中浅层构造变形样式、基底变形特征及区域应力作用特点有关。更多还原

【Abstract】 As an important boundary fault in the northern Jiangnan uplift zone,the Jiangnan fault shows its spatial-temporal characteristics of the nondiastrophic abrupt belt of sedimentary facies and the orogenic belt of tectonic deformation. In an abrupt belt that had formed before Yanshanian Period the breccia as the representative of the contemporaneous fault just plays an important part in subdivision of sedimentary facies. And the Jiangnan fault in middle and upper layers of the tectonic zone,as a whole,may be a thrust,which is presumably comprised of fault systems in different orientations or at different grades and systems of folds between these faults. The geological evidences and ESR dating indicate that faulting started from early Yanshanian Period (192.8Ma) and continued to early Himalayan Period (29-44Ma),and the fault experienced three main stages of tectonic deformation at least during this period including early thrust,middle-stage strike-slip fault and late extensional deformation. Moreover,macro-and micro-structures,homogenization temperature of fluid inclusions and e-twinning differential stress collectively suggest that the Jiangnan fault developed in a brittle,low temperature and low differential stress (20-50Mpa) environment. However,the principal traces of deformation in the middle and upper layers and formation conditions of the Jiangnan fault,which is a constitute part of thrust-nappe tectonics in the southeastern Hubei Province,reveal that the Jiangnan fault doesn′t have the tectonic attributes of discordogenic fault and is inconsistent with its characteristics spatially,in which case the contradiction may presumably be related to tectonic style of middle and upper layers,the deformation characteristics of basement rock and the action pattern of regional stress.更多还原