Before Later Proterozoic era, in this area more than two times of thermodynamic metamorphism took place.

在晚元古代以前该地区至少发生过两次热动力变质作用。

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In the bottom of coal measures is an acidic intrusive body, it is direct heat source of metamorphism, and provided the conversion of lignite to bituminous coal with thermodynamic power.

在本区煤系地层底部有一酸性侵人岩体，该侵入岩体是引起本区煤变质的直接热源，它提供了褐煤向烟煤转化的热动力。

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