湘西北早奥陶世南津关组生物丘(礁)及其形成环境

THE EARLY ORDOVICIAN(NANJINGUAN PERIOD) BIOHERMS OF NORTHWESTERN HUNAN AND ITS FORMING ENVIRONMENT

在湘西北张家界市温塘早奥陶世南津关组中部发现了小型生物丘 (礁 ) ,它们位于开阔台地与台地边缘斜坡毗邻的开阔台地边缘。经研究组成该生物丘 (礁 )的主要造礁生物之一是瓶筐石 (Calalhium) ,它具有固着、吸附和粘连周围生物或生物屑的造礁作用。笔者等的研究证实这类生物在早奥陶世南津关期业已出现 ,并有了初步繁盛 ,在此基础上 ,至红花园期有了更大的繁荣 ,广泛出现在扬子区。

The bioherms found in the middle part of the Nanjinguan Formation in Wengtang, Zhanjiajie city, Hunan lied at the edge of the open plateau. The dominant reef making creatures were Calathium and the Calathium only ocurred in Honghuayuan Formation of Lower Ordovician. Our study shows that the Calathium occurred and flourished initially in the Nanjinguan period of Early Ordovician. Furtheremore, it flourished again during Honghuayuan period of Early Ordovician and distributed in Yangtze area, China.