辽东太子河流域中石炭世若干生物礁的发现及研究

The Discovery and Study on Some Middle Carboniferous Reefs in Taizi River Basin, Eastern Liaoning

辽东太子河流域中石炭统本溪组中发现了若干个生物礁。造礁生物为ＣｈａｅｔｅｔｅｓＰｅｎｃｈｉｅｎｓｉｓ和Ａｒａｃｈｎａｓｔｒａｅａｍａｎｃｈｒｉｔａ。太子河流域的几个生物礁在生物组成、造礁方式和礁石特征等诸方面完全一致。在宏观上呈不连续天带状展布。与区域沉积相带展布方向相同。因此，本文认为它们同属一个岸礁体系。

Some reefs of Middle Carboniferous were discovered in Taizi myer basin Located in Xiaoyu limestone bed, they emerge intermittently in a row on the surface, extending east-westernly 16 kilometers. They are situated in the Niumaoling, Chigou and Yaoziyu of Benxi. The reefs are very abundant in organisms. The principal builders are Chaetetes penchiensis and Arachnastraea manchurica. Some algae also stabilized sediments by trapping and binding in the process of buildup. Accessory Organisms are Brachiopods, Bryozoans, Sponges, Crinoids, Foraminifera, Gastropod, Ostracoda, etc. The process of buildup is very simple. At the early stage, the non-typical bloherms were formed by algae on the organic bank. At the middle stage, become principal builders, Chaetetes penchiensis colonies and Arachnastraea manchurica colonies laerally linked into thick board skeleton, which covered carbonate sediments,forming strong framework of reefs. At the late stage, the principal builders disappeared rapidly,and then Crinoids began to baffle sediments helpeds disappeared rapidly, and then Crinoids began to baffle sediments helped by algae.In the end,the organisms were not able to buildup bioherms and the process of buildup stopped.The core of reefs may be divided into three microfacies in the area.They are:(1) Bindstone microfacies;(2) Bind-coverstone microfacies;(3) Bind-bafflestone microfacies.These reefs being discovered have extremely similar composition of organisms,type of buildup and character of framework in Taizi River basin. These bioherms occur in an uncontinous belt, in line with the direction of the regional sedimentary facies belt. Therefore it is considered that these bioherms belong to one fringe feef system.