岩浆接触或侵入煤层时因其高温、挥发物和压力使煤发生变质的作用。导致煤发生接触变质的，常是岩墙、岩脉、岩床等浅成侵入体，通常其覆盖层较薄，煤受其高温产生的挥发性气体较易逸出，冷却也较快。由于这种快速加热在一定程度上与炼焦过程相似，因而与岩浆侵入体直接接触的煤常转变为天然焦和高变质煤。
系统地研究了接触变质作用条件下二氧化碳释放规律，模拟计算了二氧化碳气的释放量。
The releasing rules of carbon dioxide under the condition of contact metamorphosis were systematically studied, and the releasing amount of carbon dioxide was calculated by modeling.
它们的形成可能与晚古生代古亚洲洋的消减作用有关，该期花岗岩的就位导致马家街群发生了接触变质作用。
They are probably related to the subduction of the Paleo-Asia Oceanic plate, and their intrusion resulted in the contact metamorphism of the Majiajie Group.
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