旋回地层学：地层学解读时间的第三里程碑

围绕对地质时间的认识,地层学取得了从岩石地层学、生物地层学和旋回地层学3次里程碑性的重大进展.以生物地层学为基础并与放射性同位素定年技术相结合建立的、以百万年为计时单位的地质年代表既创造了地层学的辉煌,也在一定程度上降低了地质学对精确数字定年的不懈追求和为人类社会服务的功能.本文以时间为线索,简要回顾了地层学解读时间的漫长过程,阐述了旋回地层学概念的起源、形成和发展,以及旋回地层学与层序地层学在科学目标、研究内容和研究方法上的异同.以广西晚泥盆世弗拉期-法门期之交海相碳酸盐地层为例,从理论与实践的结合上剖析了旋回地层学的研究方法以及在岩石地层学和生物地层学基础上构建高分辨率,并能与人类社会时间接轨的地质时间坐标的广阔前景和科学意义.

Cyclostratigraphy: The Third Milestone of Stratigraphy in Understanding Time

Focusing on understanding geological time,stratigraphy has made three milestone achievements characterized by lithostratigraphy,biostratigraphy and cyclostratigraphy.A geological time scale based mainly on both biostratigraphy and radiometric dating created stratigraphic refulgence,but at the cost of lowered accuracy and preciseness and weakened function of serving the human society.The paper briefly reviews the long history of stratigraphy in understanding geological time,expatiating on the origin,formation and development of cyclostratigraphical concepts,and on similarities and differences between cyclostratigraphy and sequence stratigraphy in the scientific objective,research content and method.Taking the Late Devonian Frasnian-Famennian transitional marine carbonate successions from Guangxi,South China as an example,the paper discusses the research method of cyclostratigraphy,and the prospect and scientific significance of cyclostratigraphy in establishing the high-resolution geological time scale which bridges the gap between the existing geological time coordinate with time unit of million-year scale and anthropological time units such as millennium,century and year,etc.