Facies Generation, Transformation and Destruction by Repetitive Excavation and Infilling of Burrow Networks

挖掘洞穴对显生界的许多沉积层序产生了压倒性的影响。洞穴挖掘过程与随后的风暴充填露天洞穴网络相结合，导致(1)前兆序列的消失或转换，(2)地下沉积相和分层的产生，以及(3)保存下来的沉积组构和动物群组合的产生，它们既不直接反映前驱相，也不直接反映地表沉积条件，纹理和面料。用传统的地层学、沉积学和古生态学原理分析受影响的沉积层序，会对古环境条件和层序演化产生误导的解释。该项目将表征受影响的现代层序的性质、程度和修改速度，并制定和测试识别和重新评估受影响的古代沉积层序的标准。佛罗里达州南部的碳酸盐陆架、泻湖和泥滩环境将作为这一研究计划的现代部分的研究区域。应用于古层序将使用德克萨斯州下白垩统、堪萨斯州宾夕法尼亚和新墨西哥州密西西比的石灰岩泻湖、陆架、泥滩和丘状沉积。结果将影响古岩层的环境解释和含油气潜力的评估。

Excavating burrowers exert an overwhelming influence on many sedimentary sequences throughout the Phanerozoic. Burrow excavation processes coupled with subsequent storm infilling of open burrow networks results in (1) obliteration or transformation of precursor sequences, (2) subsurface generation of depositional facies and stratification and (3) production of preserved depositional fabrics and faunal assemblages that are not a direct reflection of either precursor facies or the surficial depositional conditions, textures and fabrics. Analysis of affected sedimentary sequences using traditional stratigraphic, sedimentologic and paleoecologic principles will produce misleading interpretations of paleoenvironmental conditions and sequnce evolution. This project will characterize the nature, extent and rate of modification in affected modern sequences and develop and test criteria for recognition and reevaluation of affected ancient sedimentary sequences. The carbonate shelf, lagoonal and mudbank environments of south Florida will serve as study areas for the modern portion of this research program. Application to ancient sequences will use limestone lagoonal, shelf, mudbank, and mound deposits of the Lower Cretaceous of Texas, Pennsylvanian of Kansas and the Mississippian of New Mexico. Results will affect the environmental interpretation of ancient rock sequences and the assessment of their hydrocarbon potential.