Cambrian Ichnostratigraphy of the Eastern Basin and Range and Western Rocky Mountains

本研究主要集中在大盆地东部和落基山脉西部的生物地层学和古环境研究中利用鱼化石（生物成因沉积构造）。下寒武统微量化石研究将从四个方面进行：技术分类（系统分类）；生产方式（隧道、明沟等）；ichnostratigraphy;古生态和古地理意义。初步工作表明，该地区的鱼化石种类繁多，数量丰富。此外，潜在的痕迹制造者的各种化石组合也存在。本文将对节肢动物痕迹化石的分类分类进行修订，并制定一套可在整个类群中一致应用的分类标准。考虑将包括形态模式，结构力学，结构类型（内源性或表观遗传），以及推断的痕迹制造者。记录犹他州下寒武统及邻近地区微量化石的地层分布，并评估利用Cruziana和Rusophycus鱼种建立寒武-奥陶系地层模型的全球意义。将利用现代的痕迹制造者（例如昆虫和甲壳类动物），通过检查样品和在沉淀物水槽和水族馆实验中复制痕迹，来调查克鲁兹亚纳和Rusophycus的生产方式。将对鱼相和岩相（或岩型）之间的关系进行表征，以记录早古生代的底栖生物群落关系。微量化石还可以提供重要环境因素的详细信息，如基质浓度、盐度和沉积物缺氧。//这些因素的分布模式有助于推断局部古地理，从而使现有的区域古地理模式得到比目前更明确的界定

The proposed research focuses on the utility of ichnofossils (biogenic sedimentary structures) for biostratigraphy and paleoenvironmental studies in the eastern Great Basin and western Rocky Mountains. Four aspects of Lower Cambrian trace fossils will be studied: ichnotaxonomy (systematic classification); mode of production (tunnels, open furrow, etc.); ichnostratigraphy; paleoecologic and paleogeographic implications. Preliminary work has revealed a great diversity and abundance of ichnofossils in this area. In addition, diverse fossil assemblages of potential trace-makers also are present. A revision of the taxonomic classification of arthropod trace fossils will be undertaken, and a set of taxonomic criteria that can be applied consistently across the group will be formulated. Consideration will include patterns of morphology, mechanics of construction, the type of structure (endogenic or epigenic), and inferred trace-makers. The stratigraphic distribution of trace fossils within the Lower Cambrian of Utah and adjoining areas will be documented, and the global significance of Cambro-Ordovician stratigraphic models using ichnospecies of Cruziana and Rusophycus will be assessed. The mode of production of Cruziana and Rusophycus will be investigated by the examination of samples and the reproduction of traces in sediment flume and aquarium experiments, using modern trace-makers (e.g., insects and crustaceans). Characterization of relationships between ichnofacies and lithofacies (or lithotopes) will be made to document benthic community relationships in the early Paleozoic. Trace fossils also can furnish detailed information about important environmental factors, such as substrate consistency, salinity, and sediment anoxia. Patterns in the distribution of these factors allow local paleogeography to be inferred, which will allow existing regional paleogeographic models to be defined more clearly than they are at present.//