北京西山早、中侏罗世煤田岩浆活动特征及其与聚煤作用的关系

Features of magmatic activities and its relations to coal-accumulating in the early and middle Jurassic coal fields of the Western Hills, Beijing

对北京西山岩浆活动和聚煤作用特征的研究表明,早、中侏罗世岩浆活动与窑坡组聚煤作用关系密切,早侏罗世的岩浆活动形成火山盆地,为聚煤提供基底并引起基底隆起;窑坡早期的岩浆活动,喷出火山碎屑物质降落于湖泊,使湖水变浅成煤;煤系形成后的岩浆侵入,产生接触变质,煤层受到破坏和改造.

The features of magmatic activities and coalaccumulating in the early and middle Jurassic coal fields of the Western Hills in Beijing are studied. The result shows that the magmatic activities were closely related to the coalaccumulating. The volcanic eruption formed the basement for coalaccumulating and caused the swelling in the early Jurassic. The pyroclastic material fell down to the lake and formed coal layer during lower part of the Yaopo Formation. The magmatic intrusion metamorphosed and destroyed the Coalbearing formation after Yaopo Formation.