Small shelly fossils and carbon isotopes from the lower–middle Cambrian of Idaho (western USA)

爱达荷州中下寒武纪（美国西部）的小壳化石和碳同位素

• 批准号: 521080007
• 负责人: Professor Dr. Thomas Wotte
• 金额: --
• 依托单位: Lehrstuhl für Paläontologie / Stratigraphie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/521080007?language=en
• 关键词: Small; shelly; fossils; carbon; isotopes

The Cambrian System is presently the only Phanerozoic period characterized by the lack of a formal international subdivision. Up to now, bases of Cambrian stages 2, 3, and 4 are not defined and an intercontinental correlation of the Wuliuan Stage (base of the traditional middle Cambrian) is not possible with sufficient accurateness. One of the reasons for these problems is a pronounced provincialism of early and early middle Cambrian metazoans (especially trilobites and archaeocyaths). A way out of this misery is the combination of bio- and chemostratigraphic information. A potential non-traditional biostratigraphic tool are small shelly fossils (SSFs). SSFs have a wide distribution during the mid and late parts of the early Cambrian (Cambrian stages 2–4) as well as of the middle Cambrian (Miaolingian Series). Especially in sedimentary successions characterized by the absence of archaeocyaths or where it is hard to extract trilobites (e.g. in carbonates) SSFs deliver often the only biostratigraphic information. During the last two decades the knowledge on the potential of SSFs of worldwide early–middle Cambrian (Stage 2–Wuliuan Stage) successions has been fundamentally increased. At the same time, it becomes obvious that the data base on SSFs of western Laurentia (western Canada and USA) is still very poor. Concerning a chemostratigraphic information, carbon isotope stratigraphy has emerged as a robust correlation method in Cambrian strata. But, also for this robust marker almost no data exist for the early–middle Cambrian of western Laurentia. Above all, neither information on SSFs nor any chemostratigraphic data exist for the well-preserved early–middle Cambrian successions of Idaho. Aim of the project is the first time investigation of SSF fauna and carbon isotopes of Idaho (1) to improve a bio-chemostratigraphic subdivision and correlation of the Cambrian of western Laurentia and (2) to shed new light on the ecology and evolution of Cambrian ecosystems.

寒武纪系统目前缺乏正式的国际分区。早期和早期的MBRIAN后生动物（尤其是三叶虫和考古学），潜在的非传统生物地层工具Shelly化石（SSF）在沉积物中，由于缺乏考古学或很难提取三叶岩（例如在碳酸盐中）的地方，在过去的二十年中静止的一种相关方法，在cambrian地层中，既不存在SSF的信息，也没有任何化学的地层数据，即保存完好的早期中部寒武纪Aime的副总统为了改善西方劳伦山脉寒武纪和（​​2）的c细分和相关性，以对寒武纪生态系统的生态学和进化进行新的启示。