海侵事件成煤作用——一种新的聚煤模式

晚古生代华北陆表海聚煤盆地海平面具有高频率变化和复合性特点，海侵具有突发事件性，这一规律对盆地充填沉积、沉积体系演化和煤聚积具有控制作用。提出了“海侵事件成煤观点”，认灵海侵事件成煤是大型陆表海盆地所特有的，陆表海盆地的海侵过程是非常短暂的，表现出海侵具“突发”性质，因此海侵沉积具有较好的等时性。煤层与直接覆盖于其上的海相灰岩为一种事件沉积组合，泥炭的煤化作用过程完全处于还原环境下。

COAL FORMATION IN TRANSGRESSIVE EVENTS -- A NEW PATTERN OF COAL ACCUMULATION

The sea level changes in the North China Paleozoic epicontinental basin were of high frequency, and the transgressive events were episodic. This kind of sea level changes controlled both the basin filling and the coal accumulation within the basin. Since the transgressive coal accumulation pattern being presented by Diessel (1992), there comes an great upsurge in the study of coal accumulation in transgressive process. Diessel’s theory originated from the marginal continent basin and not fit well to the epicontinental basin. Coal formation pattern in transgressive event differs from either the coal formation in the transgressive process or that in the transgressive system tracts. The authors hold the opinion that the “events” are the main controlling factor in the coal formation. The North China Paleozoic epicontinental basin was a dish like one with flat basement, which led to the transgressive events being episodic and of eventness and has great influence on the coal formation. The coal formation occurred in the period of the rapid transgressive events and were consequently overlaid by marine sediment. Thus the coalification occurred in a reduced environment. Coal bed presents basically a isochronous surface. There is a condensed interval between the coalbed and its overlying marine sedimentary bed. The condensed interval maybe the coal bed itself or the lower part of the marine sediments. Coal beds and their overlying marine limestone are the sedimentary combinantion.