德国泥盆纪生物礁的基本特征

德国泥盆纪的层孔虫十分繁盛，不同形态、不同规模的层孔虫礁体广泛发育于台地内部、台地边缘和深海盆地内的火山周日。块状层孔虫是主要的造礁生物，四射珊瑚也参与了造礁，但数量极少。礁区岩相分异明显，盆地相、礁前相、礁核相和礁后泻湖相清晰可辨。部分礁体，如布瑞隆环礁显示清楚的初殖、拓殖、繁殖和衰亡四个演化阶段。层孔虫礁的主要繁盛期为吉维特期－弗拉斯期。德国泥盆纪生物礁的基本特征类似于加拿大同时期的生物礁，但在德国泥盆纪的礁灰岩杂体内至今尚未发现有经济价值的石油和天然气。这可能与莱茵海西地槽复杂的地质发展史有关。

CHARACTER OF DEVONIAN REEFS IN GERMANY

Devonian stromatoporod reefs with various sizes and forms in Germanyare developed in theinterior of the shelf,on shelf margia and around the vnlkans of the deep sea basin,Massive stromatoporids were main reef-builder,corals took part in thereef-building,too,but they played a secondary role. The facial differentiation in the reefregion,such as basin facies,fore-reef facies,reef-core facies and back-reef facies withlagoon,are recognized.Some of reefs,e.g. Brilon atoll include 4 typical developmentalphases:stabilization,colonization,diversification and dead.The most important reef-building phase lasted from Givctian to Frasnian,Character of Devonian reefs in Germanyare similar to the reefs with the same age in Canada. But in Germany no economic oil andgas in Devonian reef limesstone complexes are found.This depends probably on thecomplex development history of the rhenish geosynoline.