江汉平原构造演化与中、古生界成藏模式探讨

江汉平原自晚元古代变质基底形成,中扬子准克拉通化之后,先后经历了加里东、海西～早印支、晚印支～早燕山以及晚燕山～喜山期四次大的构造旋回,空间上形成了海盆、煤盆和盐盆纵向叠置的＂三层楼＂构造格局.江汉平原构造的复杂演化过程,使江汉平原海相地层具有改造盆地的特点,也决定了本区的成藏基本地质要素动态演化的复杂性,即＂烃源岩热演化程度之高极为鲜见,后期改造十分强烈＂,造就现今江汉平原海相改造盆地油气成藏规律与原型盆地的成藏规律差别极大,因此具有早期聚集早期成藏、早期聚集晚期成藏、晚期生烃晚期成藏及次生混源等多种成藏模式.

RESEARCH ON TECTONIC EVOLUTION AND RESERVOIR-FORMING PATTERN OF MESOZOIC GROUP AND PALEOZOIC GROUP IN THE JIANGHAN PLAIN

Since an entire metamorphic basement was formed during the Latter Proterozoic era and then semicratonized during the Midian Yangtze period ,4 great tectonic cycles have happened in the Jianghan Plain, i. g. Caledonian, Hercian - Early Indosinian, Latter Indosinian - Early Yanshanian and Latter Yanshanian - Himalayian Cycles, which resulted in a three - storey - typed tectonic framework in special consisting of superposed sea basin, coal ba- sin and salt basin. It is the complex tectonic evolution process that formed the marine strata in the Jianghan Plain with characteristics like that of a reformed basin . It also resulted in a complex, active evolution in essential geological elements for reservoir formation in the area,which means an extraordinarily high degree of thermal evolution in hydrocarbon source rocks and a strong latter reformation. Therefore, a distinct contrast in reservoir - forming law occurs between the present reformed marine basin and the original basin in the Jianghan Plain. The reformed basin has a variety of reservoir - forming patterns including earlier hydrocarbon accumulation - early reservoir formation ; earlier hydrocarbon accumulation - latter reservoir formation ; latter hydrocarbon generation - latter reservoir forma- tion, and secondary multi -sourced patterns.