深部地质结构对浅层地质与成矿作用的制约——以中国东部大陆及海区为例

根据十余年来参加中国岩石圈三维结构研究和国际合作编图资料,将深部地质结构与浅层地质、成矿特征进行统一的综合分析研究,对中国东部及邻近海域地质构造取得一些新认识,提出一些新观点:(1)在中国大陆及邻近海域400 km深度内,划分出5层地质结构,其中第3、4层之间的变化制约了浅层地质与成矿作用;(2)中国大陆及海区受周边动力挤压,其中西部挤压力大于东部,导致西部软流圈物质经4条路径向东流动,使东部汇聚巨大巨厚的软流圈,形成独特的软流圈巨量热能(力)-动力主体动力区,构成了亚洲大陆第4个主体动力区;(3)太平洋板块俯冲力制约了北纬42°40'以北的完达山及俄罗斯远东地区,菲律宾海板块俯冲力制约了台湾和中国东南沿海地区,二者的动力之和构成了阻挡软流圈物质向东部洋区流动的"远程力效应";(4)软流圈巨量热能(力)-动力作用的主体动力区打造了中国东部及海区7项地质、地貌特征和三大类矿产资源效应。其中岩浆活动与化石燃料矿产(石油、天然气、煤)之间不是"水火不相容",而是岩浆活动为提升油-气成熟度和煤化作用及变质作用提供了重要的温度条件;(5)软流圈巨量热能(力)-动力作用打造了中国东部及海区一些独有的地质作用:①形成了新生代南海小洋盆,并向巴拉望岛俯冲。②产生了新生代陆缘裂谷带,形成了琼州海峡、台湾海峡,并向台湾岛轻度俯冲。③大面积的巨厚软流圈是一座"巨型岩浆山",成为东部及海区"地幔柱"的统一"根基"。地幔柱实际上是巨大"岩浆山"中的"岩浆山峰",今后会发现更多"地幔柱"(即"岩浆山峰")。④中国东部地震除吉林省珲春地区的深源地震(540 km)外,朝鲜半岛及其以西的中国东部和海区均为浅源与中深源地震(震源深度小于100 km),其主体动力都来自本区巨量热能(力)-动力源,太平洋板块-菲律宾海板块的联合俯冲力只起了"远程力效应"的深部侧向挤压辅助作用。⑤巨量热能(力)-动力作用形成了一系列盆-山耦合带,组成了中国东部及海区中-新生代"盆-山耦合群","盆"里有油气资源,"山"里有内生矿产。

DEEP GEOLOGICAL STRUCTURE CONSTRAINTS ON SHALLOW GEOLOGY AND MINERALIZATION: A STUDY IN THE LAND AND SEA AREAS OF EAST CHINA

Based on the research of the 3D Model of Lithospheric Structure supported by the international cooperation mapping project among China and surrounding countries, and the comprehensive analysis and study of deep geological structures, shallow geology and mineralization, the authors proposed the following ideas in this paper:① up to the depth of 400 km, in the land and sea areas of East China, there are five tectonic layers. The variations of the third and fourth layers constrains the shallow geology and mineralization; ②The land and sea areas of East China are under the squeezing pressure from surrounding areas, in which the pressure from the west dominates, resulting in the accumulation of great amount of asthenospheric materials and the formation of a large thermal energy and dynamic region. As the result, the forth power area is formed in the Asian Continent; ③the suduction of the Pacific Block ends at the latitude of 42°40'N along the Wandashan Mountain and the Far East of Russia, while the subduction of the Philippine Sea Block ends along Taiwan and Southeast coastal area of China. The joint action of the above-mentioned two forces drives the asthenospheric materials flowing to the Eastern sea area; ④the huge amount of energy from the asthenoshere, and the dynamic effect derived from the movement caused the formation of seven geological and morphologic features and three kinds of mineral resources in the land and sea areas of East China. The relationship between magmatism and the fossil fuel resources, such as petroleum, natural gas and coal, is not always negative. Magmatic activities may provide important thermal conditions necessary for oil-gas maturation, coalification and metamorphism; ⑤the huge amount of energy from the asthenosphere as well as its dynamic effect, may bring about some unique geological effects in the land and sea areas of East China; a, formation of some Cenozoic small oceanic basins, which have subducted to the Palawan Island; b, formation of some Cenozoic continental margin rift belts and the formation of the Qiongzhou Strait and Taiwan Strait, and the slight subduction towards the Taiwan Strait; c, the enormous accumulation of the asthenospheric materials caused the formation of a "giant Magmatic Mountain", which is in fact the source and foundation of the mantle plumes in the land and sea areas of East China. Each mantle plume is the peak of the Magmatic Mountain. It is believed that more mantle plumes or Magmatic Mountain peaks will be discovered in the future; d, except the deep earthquake (540 km) happened in Huichun of Jilin Province, most of the earthquakes in the Eastern China, as well as those occurred in Korean Peninsula and to the west of it in the land and sea areas of East China are mainly shallow and intermediate ones (<100 km), the main energy of which is from the giant thermal accumulation, the source of the earthquakes and the subduction of the Pacific Block and the Philippines Sea Block only play a limited role as a supplement to provide remote stresses; e, The giant thermal energy and dynamic movement results in a series of basin-mountain coupling belts in the land and sea areas of East China. There are energy resources in basins, and mineral resources in mountains.