华南泥盆纪层序地层系、统、阶界线的建立与生物地层、年代地层界线的对比

THE ESTABLISHMENT OF THE SYSTEM,SERIES AND STAGE BOUNDARIES AND CORRELATION OF BIOSTRATIGRAPHIC AND CHRONOSTRATIGRAPHIC BOUNDARIES IN THE DEVONIAN STRATA IN SOUTH CHINA

关键词:  华南  泥盆纪  层序地层系、统、阶界线

Key words:  South China  Devonian  system  Series and stage boundaries of sequence stratigraphy

摘要:

本文以EXXON公司P.R.Vail等人创立的层序地层学理论为准。对华南泥盆系的层序地层进行了区域上的研究、分析、对比.研究结果表明,从下泥盆统的洛赫科夫阶至上泥盆统的法门阶可识别出20~21个Ⅰ级层序.华南泥盆系的岩石地层、生物地层、年代地层的系、统、阶界线均已确定。与层序地层研究结果对比,生物地层界线均比相应的层序地层界线滞后。本文试图以层序地层序列为准,建立一新的地层系统作为相应的生物地层、年代地层的系、统、阶相对应的辅助性地层系统.研究结果表明。在岩石地层、生物地层、年代地层研究程度高的地区,可建立层序地层的系、统、阶界线系统以利于野外作业。华南地区的泥盆系内。除弗拉斯阶与法门阶的阶间界线置于饥饿层(starved section)外,其他的阶、统、系界线均位于有关阶(统)顶部层序中的HST的顶面.

Abstract:

In this paper regional analysis and correlation have been conducted on the sequence stratigraphy of the Devonian strata in South China according to the theory of sequence stratigraphy created by P.R.Vail et al.from Exxon Corporation.The results of research have shown that more than twenty third-order sequences may be recognized from the Lochkovian to Famennian.The boundaries of various stratigraphic units such as system, series and stage of Devonian lithostratigraphy,biostratigraphy and chronostratigraphy of South China have been well defined,and by comparison the boundaries of biostratigraphy tend to be later in ages than their corresponding boundaries of sequence stratigraphy. In the light of the criteria for the recognition of sequence stratigraphy,the author at-tempts to establish a new auxiliary stratigraphic system with its defined boundaries of sys-tem,series and stage which are comparable with those of the biostratigraphy and chronos-tratigraphy.The results have revealed that a boundary system of sequence stratigraphy should be established to make things easy for stratigraphyic correlation in the field when-ever the degrees of research on lithostratigraphy,biostratigraphy and chronostratigraphy permit,and that all the boundaries of the system,series and stage of the Devonian strata in South China are located at the top surface of the highstand systems tract of relevant strati-graphic units'in the sequences except the boundary between the Frasnian and Famennian which is located in the starved section.