Late Eocene-early Oligocene radiolarian events and abundances in ODP Leg 199 sediments

During Ocean Drilling Program Leg 199, eight sites (Sites 1215-1222) were cored in the Central Pacific. Late Eocene-early Oligocene thick radiolarian-rich biogenic sediments were collected from Holes 1218A, 1219A, and 1220A. This is the first attempt to calibrate the ages of Paleogene radiolarian events using magnetostratigraphy in this region. A total of 107 species and species groups, which are valuable for stratigraphic correlation, are listed with numeric data and figures. Among these three holes, a total of 77 radiolarian events were recognized and their ages were calibrated by correlation with paleomagnetic events recorded in Hole 1220A.

在大洋钻探计划（Ocean Drilling Program）第199航次期间，科研人员在中太平洋海域完成了8个站位（1215至1222站位）的岩心钻探作业。本次工作从1218A、1219A及1220A三个钻孔中采集到了晚始新世—早渐新世时期的厚层富放射虫生物成因沉积物。这是该区域首次利用磁地层学（magnetostratigraphy）对古近纪放射虫事件的年代进行校准的尝试。研究共列出了107个具备地层对比价值的放射虫物种及物种群，并配套提供了数值数据与图像资料。在上述三个钻孔中，共计识别出77处放射虫事件，并通过与1220A钻孔中记录的古地磁事件进行对比，完成了这些事件的年代校准。