Paleogene Biostratigraphic Correlations of the Pacific Northwest

9406325 Nesbitt该项目是一项修订和完善俄勒冈州西部海相古新世岩石年代地层对比的研究。华盛顿、不列颠哥伦比亚省和阿拉斯加半岛。目前为这些岩石定义的生物地层学方案有许多误差来源。由于缺乏对相控制的认识、动物群的时间超越性以及生物地理上的地方性，这些问题一直存在。这项研究将评估现有的软体动物生物区，并在需要的地方定义新的生物区。软体动物分区方案将与目前在该地区工作的合作微古生物学家提供的有孔虫和钙质超微浮游动物数据相关联。将从合适的沉积单元中夹层的凝灰岩和其他火山岩中获得放射性日期。太平洋西北部的纬向方案将与世界时间尺度相关联。这种精确、可靠和具有全球意义的年代地层学将成为未来无脊椎动物和脊椎动物系统发育、动物群对全球气候变化的反应和边界灭绝等研究项目的基础。

9406325 Nesbitt The proposed project is a study to revise and refine the chronostratigraphic correlation of marine Paleocene rocks of western Oregon. Washington, British Columbia and the Alaskan Peninsula. The currently defined biostratigraphic scheme for these rocks has numerous sources of error. These have been perpetuated because of the lack of recognition of facies controls, time- transgressive nature of the faunas, and biogeographical provincialism. This study will evaluate the existing molluscan biozones and define new biozones where needed. The molluscan zonal scheme will be correlated with foraminiferal and calcareous nannoplankton data supplied by collaborating micropaleontologists who are currently working in this area. Radiometric dates will be obtained from tuffs and other volcanic rocks interbedded within the appropriate sedimentary units. The zonal scheme for the Pacific Northwest will be correlated with worldwide time scales. This refined, reliable and globally relevant chronstratigraphy will be the foundation for future research projects on invertebrate and vertebrate phylogenies, faunal response to global climate changes, and boundary extinctions.