摘要
研究表明,巴楚地区一间房组生物礁具有6项特征:①单个礁体规模小,礁体多;②含礁层系由主礁体层和次礁体层组成;③礁体形态多种多样,与围岩均为突变接触;④礁体构成简单,微相类型单一;⑤Calathium呈高丰度、低分异度、原地生长、原地埋藏;⑥礁核内发育水道充填体。在生物礁发育的诸多控制因素中,水动力作用即存在建礁作用,也存在着毁礁作用。前者反映水流作用建造了局部的浅滩,产生了礁基有利于Calathium等的繁殖,强化了粘结作用和障积作用,促进了礁体的生长。后者则冲蚀了礁体的外形和内部的完整,改变了建礁生物的原身状态,限制了礁体的规模、形态直至发育,建礁作用和毁礁作用相互作用的结果,使得中奥陶世生物礁经历了奠基期,建礁期和毁礁期。
There exist 6 characteristics of reef features which include individual reefs are small, but numerous; ②the reef-bearing in the middle member of the Yijiangfang Formation is composed of a lower main reef unit and an upper less well developed reef unit; ③the reefs have various shapes and exhibit sharp contacts with surrounding strata; ④faunal and floral reef components are relatively simple, and their microfacies are relatively monotonous; ⑤calathium occurs in great abundance, but low diversity, and has autochthonous occurrences as both living and buried elements; ⑥Channel fills may be developed within the reef cores. Among the various reef growing-controlling factors are the hydrodynamic conditions that affect both reef construction and destruction. Local shallw-water sand bars is served as reef bases, is beneficial for the establishment and growth of Calathium, and strengthening the binding and baffling actions that modified reef growth. Subsequent currents erode the reefs, wash out and destroy their original outlines and shapes, and affect completeness of preservation of reef interiors. Erosional processes modify the growth of reef-building organisms, and restrict the scales and shapes of the developing reefs. The interactions between reef-building and reef-destruction process; therefore, it results in three main stages of development of these middle Ordovician reefs: such as foundation stage, reef construction stage and destruction stage.
出处
《石油天然气学报》
CAS
CSCD
北大核心
2006年第3期13-16,共4页
Journal of Oil and Gas Technology
基金
国家教育部科技司重点项目(03086)
