Late Miocene to Holocene planktonic foraminifers from ODP Leg 108 holes

Planktonic foraminifers were examined from 27 holes situated at 12 separate sites in the tropical Atlantic. The sites are located in various environments, including areas of upwelling, areas affected by cool currents, areas of strong dissolution, and areas that show little dissolution in warm-water settings. Paleomagnetic results were variable at these sites, but accumulation rate curves have been produced by combining the existing paleomagnetic data with the available microfaunal data. Determinations of the ages of the planktonic foraminifer datums from these accumulation rate curves show some species to be strongly diachronous, while others provide good stratigraphic markers. The warmest water sites with the least dissolution show the most complete ranges of species.

本研究针对热带大西洋12个独立站位的27个钻孔中的浮游有孔虫（Planktonic foraminifers）展开分析。上述站位分布于多种沉积环境，涵盖上升流区、受寒流影响的海域、强溶解作用区以及暖水环境下溶解作用极弱的区域。各站位的古地磁（Paleomagnetic）结果存在一定差异，但通过整合现有古地磁数据与可获取的微古生物数据，已构建出沉积速率曲线。基于上述沉积速率曲线对浮游有孔虫标志面的年龄进行测定，结果显示部分类群的出现或消失时间具有显著穿时性，而另一部分类群则可作为优质的地层标志。其中溶解作用最弱的暖水站位，其浮游有孔虫的物种延续序列最为完整。