板块构造与幔柱构造的相互关系——以中国东部中、新生代控矿因素为例

侏罗纪以来,太平洋板块与欧亚板块俯冲碰撞,促成了中国东部以NNE-NE向断裂为主体的断裂构造格局。从地震面波层析成像反演资料及东北和华北地质剖面得知,该地区应属东亚巨型宽裂谷体系的东部地区,系亚幔柱活动所致。全区P波速度、岩石圈不连续和减薄转型、软流圈物质呈蘑菇云状上升以及大火成岩省等特征证明中国东部中、新生代为亚幔柱构造控制成矿成藏,从而证实板块构造与幔柱构造相辅相成的关系。幔柱构造可划分3级,金属矿床常受幔枝构造的控制,多成群成带分布。由于成矿物质来自深部地核或软流圈,金属元素呈垂直分带的规律成为"攻深找盲"的理论依据;而油气田深部常受深部热源影响,若有海相烃源层分布,是寻找"无机"和海相油气田的主攻目标。

Inter-relation of plate tectonics and mantle plume tectonics: in case of Mesozoic and Cenozoic ore control factor in east China

Subduction and collision of Pacific plate and Eurasian plate since Jurassic Period resulted in the dominant big NNE-NE fault configuration in east China. From the seismic surface wave tomographic inversion data and geological section of the northeast and North China, the east China should belong to the east part of the Eastern Asian giant rift system which originated from the sub-mantle plume tectonics. The characteristics of the P wave velocity data, the lithospheric discontinuities and thinning transformation, asthenospheric material moving up in mushroom cloud and large igneous province, all the features indicate that Mesozoic and Cenozoic sub-mantle plume tectonics controls mineralization and hydrocarbon accumulation and plate and mantle plume tectonics interact with each other. The mantle plume tectonics can be divided into three sub-units of which the mantle branch controls metal deposits. The metal deposits tend to occur in groups or belts and their ore materials come from core and asthenosphere. Due to the metal elements show vertical zonation thus the mantle plume is the theoretical target for deep and blind metal deposit prospecting. If there is marine hydrocarbon rock at the mantle plume which will be the target for "inorganic" and marine oil and gas field.