事件地层学在生物礁研究中的应用

Applications of Event Stratigraphy to the Study of Organic Reefs

事件地层学不但在地层划分和对比中成为重要手段,而且在沉积学领域中的运用,也猛烈冲击了一些传统的沉积学观念,给沉积学研究领域注入了活力。人们越来越认识到,在地质历史中,沉积作用常常伴有突发的、不连续的地质事件。如众所周知的浊流、风暴、洪水、海啸等沉积。这些事件沉积无疑给沉积学研究方面开辟了新的思路和方法。

Organic reefs commonly serve as the criteria for recognition of sedimentary facies and palaeoclimate. The following three types of the covers of reefs are often believed to result in the death of the organic reefs:(1)the deep-sea sediments;(2)sandstones and mudstones, and(3)evaporites. Many sections of reefs and their covers indicate the alternation of growth and death, i.e., the alternation of normal and abnormal conditions and of stable and catastrophic periods. Therefore, vertical profiles through the reefs and their covers can only be explained in terms of catastrophism instead of gradualism. The dramatic subsidence or rise are usually thought to be a leading factor resulting in the sudden death of the organic reefs. It is clear that the death of the organic reefs may represent regionally the beginning of event sedimentation. The development and distribution of the organic reefs on both temporal and spatial scales can be studied by the event sedimentological method.