Upper Eocene Spherule Layers: Number, Geographic Extent, and Source Areas

两种不同类型的上始新世球粒已经被描述过：1)属于北美球粒散落区的微球粒；2)含斜辉石球粒。始新世球粒层数存在争议。拟议研究的目的是利用海洋钻探项目15-20个地点的岩心样本，确定球体层的数量及其地理范围。我们还将寻找相关的撞击抛射物。球粒的生物地层资料、岩石学和成分（主要、微量和同位素）以及任何相关喷出物的性质将用于整理球粒层的数量。球粒丰度的地理变化以及岩石学和成分数据将用于确定每个球粒层的母物质和源区域（如果可能的话，还有源陨石坑）的性质。

9903811Glass Two different kinds of upper Eocene spherules have been previously described: 1) microtektites belonging to the North American tektite strewn field, and 2) clinopyroxene-bearing spherules. The number of Eocene spherule layers is in dispute. The purpose of the proposed research is to determine the number of spherule layers and their geographic extent using Ocean Drilling Project core samples from 15-20 sites. We will also look for associated impact ejecta. Biostratigraphic data, petrography and composition (major, trace, and isotopic) of the spherules, and the nature of any associated ejecta will be used to sort out the number of spherule layers. Geographic variations in spherule abundance and petrographic and compositional data will be used to determine the nature of the parent material and the source area (and, if possible, the source crater) for each spherule layer.