遗迹组构研究现状及进展

The current achievements and potential of ichnofabric

遗迹组构是由生物成因改造的沉积岩组构,是物理过程和生物过程相互作用的产物.近年来,遗迹组构分析其日益增长的意义主要表现在含油气盆地地层单元成因环境的精确解释和各类不连续面的精细识别.从以下4个方面分析了目前国内外遗迹组构的研究现状和应用前景:遗迹组构与关键地层界面的识别,不同的遗迹组构区分出了9种关键地层界面,这些关键地层界面上下由于流体运动、缺失、侵蚀、固结、成岩、沉降、上升等作用会发生变化,但可通过生物群落的再殖居表现出来;对复杂遗迹化石和遗迹组构的精细研究和重新解释,包括遗迹化石自身结构的复杂性、功能的多样性、造迹生物行为习性的多样性和复杂性以及多期造迹生物对底质的多重叠加改造;对一些复杂遗迹组构来说,搞清遗迹化石造迹过程、造迹方式、造迹深度及与其他遗迹的世代阶层关系等,特别需要对遗迹组构进行三维可视化分析和计算机模拟.实践证明,遗迹化石研究不仅在油气勘探中大有用武之地,而且在油气生产中也能发挥重要作用.遗迹组构能以多种可预测的方式改变地层的渗透率.

Ichnofabric is sedimentary rock fabric resulting from biogenic reworking, which is generated by interaction of physical and biological processes. Ichnofabric analysis displays a rising significance on accurate environmental interpretation of sedimentary units in oil - bearing basin and precise recognition of depositional disconuities. The paper summarizes current achievements and potential of ichnofabric in four aspects： Nine key stratal surfacies can be differentiated by the different ichnofabrics and change in flow regime, omission, erosion （at all scales） , consolidation and lithification, subsidence, uplift, emersion. Each of these may be reflected in the biotic recolonization by animals and/or plants which typically accentuate the key stratal surface ; detailed study and re - explanation of complex trace fossils and ichnofabrics depend on the study of com- plex of ichnofabric itself, diversity of function, diversity and complex of behaviour of tracemarkers and multiple juxtaposed reworking of different shape of tracemarkers; it it much important for study of complex ichnofabrics to exactly understand the process, mode of tracemaking and its depth and relationship between different tiers, especially need the three - dimensinal visualization analysis and computer simulation of ichnofabric ; the facts of oil exploration show that study of trace fossils can not only be widely used in petroleum geology, but also by used in oil production, and the ichnofabrics can change the permeability of strata by different predicted methods.