Conodont Biostratigraphy of the Upper Cambrian -- Lowest Ordovician and International Correlation of the Cambrian-Ordovician Boundary

寒武-奥陶纪牙形刺数量丰富，同类牙形刺的分布较同时代其它化石群更为广泛。由于它们的用途，它们将是寒武系-奥陶纪界线国际工作组在选择界线点时使用的主要群体。该项目将资助PI作为该委员会秘书的持续工作。该项目的其他方面是研究寒武-奥陶纪海平面升降波动。将与研究过内华达州地层和哈萨克斯坦同等地层的美国地质调查局人员合作，研究这些海平面变化期间沉积的内华达州地层。这部分研究的目标是将这些地区台地和陆坡沉积物中的异常沉积模式联系起来。本研究的最后一个方面是继续进行犹他州西部寒武-奥陶纪牙形刺的生物地层学和古生态学项目。该区的岩相变化使其成为研究寒武-奥陶纪牙形石古生态及岩相变化对牙形石生物地层学影响的天然实验室。其中一些相变与上文讨论的海平面升降波动有关，并可与内华达州、哈萨克斯坦和其他地区的沉积模式数据相关联，以形成这些海平面升降事件影响的综合图像。这些事件与动物群的变化和演化有关，在明智地选择寒武纪-奥陶纪界线之前，必须了解这些变化。

Cambro-Ordovician conodonts are abundant and the same species are more widely distributed than other contemporaneous fossil groups. Because of their utility they will be the primary group utilized for choice of a boundary point by the International Working Group on the Cambrian-Ordovician Boundary. The project will fund the PI's continuing work as Secretary of this committee. Other aspects of the project are study of Cambro-Ordovician eustatic sea-level fluctuations. Strata in Nevada deposited during these sea-level changes will be studied in cooperation with U.S. Geological Survey personnel who have studied the Nevada strata and equivalent beds in Kazakhstan. The goal of this part of the research is to correlate unusual sedimentation patterns in platform and continental-slope deposits in these areas. A final aspect of the study is continuation of a project on biostratigraphy and paleoecology of Cambro-Ordovician conodonts in western Utah. Facies changes in the area make it a natural laboratory for study of the Cambro-Ordovician conodont paleoecology and the influence of facies changes on conodont biostratigraphy. Some of these facies changes are related to the eustatic fluctuations discussed above and can be correlated with data on sedimentation patterns in Nevada, Kazakhstan, and other areas to form an integrated picture of the effects of these eustatic events. These events are related to faunal extinctions and evolutionary changes which must be understood before a Cambrian-Ordovician boundary point can be chosen wisely.