浅析华北板块中元古代—古生代构造格局及其演化

通过对区域地层层序特征、沉积 生物 构造古地理的综合分析 ,提出华北板块经历了中、新元古代边缘裂陷阶段和古生代全域性差异升降阶段两大构造演化阶段。其中 ,前者可进一步划分为中元古代强裂陷亚阶段及新元古代弱裂陷亚阶段 ;后者可进一步划分为早古生代弱差异升降亚阶段和晚古生代强差异升降亚阶段。其间发生了 3次划时代的构造运动 ,即芹峪运动、蓟县运动和秦皇岛运动 ,这些运动均影响板块全域 ,成为划分板块构造演化阶段的标志。每次构造转换后均出现特征鲜明、近乎覆盖全域的同期、近同期的沉积标志层。分析表明 ,华北板块在中元古代至古生代长达 15 0 0Ma间 ,似乎从未经历过大规模的水平挤压运动 ,即没有与毗邻大板块有过大规模的碰撞与对接 ,而是长期独自发展 ,漂移、徘徊于赤道两侧低纬度区或在中低纬度区。

THE PRELIMINARY RESEARCH ON TECTONIC PATTERN AND TECTONIC EVOLUTION OF MESOPROTEROZOIC-PALEOZOIC IN NORTH CHINA PLATE

On the stratigraphic sequence and sedimentary-biology- tectonic paleogeography analysis, two tectonic stages, which are depressed stage of the plate margin in Meso-Newproterozoic and differential depressed stage of whole plate in Palaeozoic, of the North China Plate were brought on in this pap er. The depressed stage of the plate margin in Meso-Newproterozoic can be furth er divided into two substages, violent depressed stage of the plate margin in Me soproterozoic and weak depressed stage of the plate margin in Newproterozoic. Th e differential depressed stage of whole plate in Palaeozoic can be further divid ed into two substages, strong differential depressed stage of Early Palaeozoic a nd weak differential depressed stage of Later Palaeozoic. Three major tectonic m ovements, which are Tieling Movement(1,400 Ma), Jixian Movement(1,000 Ma) and Qinhuangdao Movement (470 Ma), were occurred from Mesopr oterozoic to Palaeozoic. These movements affected the whole plate and became a s ymbol to divide tectonic stage of the plate. Some marked bed, which was formed i n same or near same epoch and covered the whole plate, were formed the end of ev ery tectonic stage. Large scale level tectonic movement never occured from Mesop roterozoic to Palaeozoic. In other words, the North China Plate did not occur la rge scale impact with neighbor plate. It independently developed and walked in l ow or middle-low latitude region on both sides of equator.