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为确定华北板块南缘高变质煤条带形成机制与形成时代,通过研究华北板块南缘中二叠统山西组二1煤层煤级分布和岩浆岩空间展布特征,结合华北板块与扬子板块碰撞历史,利用地质学“重力均衡”原理和日本岩石学家都城秋穗提出的“双变质带”理论,建立碰撞热流模型并合理解释导致高变质煤条带形成的热流来源,得出:1)扬子板块向华北板块的俯冲作用,在华北板块南缘前陆盆地形成高温低压带,促进了煤化作用,形成高变质煤条带;2)结合地质资料和区域构造特征分析,发现高变质煤带走向与印支期构造走向(东—西)一致,该高变质煤条带形成于印支期。燕山期岩浆控制了华北板块南缘大部分煤变质作用,但是在晋城—济源一带其煤变质是由于印支期板块碰撞形成的异常热作用的结果。
In order to determine the formation mechanism and formation age of the high metamorphic coal belt in the southern margin of North China Plate, by investigating the distribution of coal rank and the spatial distribution of magmatic rocks in the No.2 coal seam of the Middle Permian Shanxi Formation in the southern margin of the North China Plate, and combining the collision of the North China Plate and the Yangtze Plate History, using the theory of geology “gravity balance ” and the theory of “double metamorphic belt ” proposed by Japanese petrographer Akutagawa to establish the collision heat flow model and reasonably explain the source of heat flow that led to the formation of highly metamorphic coal strata The results are as follows: 1) Subduction of the Yangtze Plate to the North China Plate resulted in the formation of a high-temperature and low-pressure belt in the foreland basin in the southern margin of the North China Plate, promoting coalification and forming a highly metamorphic coal belt. 2) Based on the analysis of geological data and regional tectonic features, The metamorphic coal belt is consistent with the Indosinian tectonic strike (east-west), and the metamorphic coal belt was formed during the Indosinian. The Yanshanian magmatic controlled most of the coal metamorphism in the southern margin of the North China Plate. However, the coal metamorphism in the Jincheng-Jiyuan area was the result of anomalous thermal effects caused by the Indosinian plate collision.