沉积记录研究的现代过程视角

沉积记录是揭示地球演化的主要数据来源之一,地层学提供了宏观大尺度沉积记录的分析方法,而沉积学则提高了沉积记录的时空分辨率。但上述方法主要是针对沉积体系特征和现象信息的,而有关沉积体系过程和机制信息的提取还较为薄弱。通过评述现代过程在沉积记录研究中的定位,提出了新的科学问题。研究结果表明,基于现代过程研究的勘测性模拟是一种值得追求的方法。经典数值模拟依赖于未知变量与方程个数相同的控制方程,用实测数据作为验证材料,而勘测性模拟是控制方程加工作假说构成的体系,其模型输出指示了过程—产物关系。因此,通过现代沉积体系模拟及其与钻孔资料的对比,可以获取沉积记录所含的过程和机制信息。勘测性模拟也是地球久远时代沉积记录的潜在分析工具。

Discover More Information from Sedimentary Records: Views Based on Contemporary Earth Surface Dynamic Processes

The purpose of this paper is to discuss and review the methodology of sedimentary record studies adopted in stratigraphy and sedimentology and to propose new research directions. Sedimentary records are the major data source for the study on earth's history,which are dealt with by stratigraphy and sedimentology,using macro-temporal scale and high resolution analyses,respectively. However,the information thus obtained is associated mainly with the char-acteristics of the deposits or the environment in which the deposits were formulated, with little information on the processes and mechanisms for the formation of the records. Here I propose a method of"prospective modeling"to ex-tract the process and mechanism information from the sedimentary record. Classical numerical modeling is a system containing governing equations with the same number of unknowns,with the model output being calibrated against ob-servations. In contrast,prospective modeling depends on a combination of governing equations and working hypothe-ses. The working hypotheses are evaluated against sedimentary records. As such,once established, the model output reveals the process-mechanism information in the sedimentary records.Prospective modeling may also serve as a poten-tial tool for analyzing the stratigraphic records formed in the geological past.