Planktonic foraminifera stratigraphy and datums of ODP Site 184-1143 and Hole 184-1146A, South China Sea

The biostratigraphy of Miocene-age sediment samples recovered from Ocean Drilling Program Sites 1143 and 1146, South China Sea, is presented. The preservation of the planktonic foraminifers recovered from both sites varies widely, from poor to very good. The volume of biogenic sediment in the >63-µm size fraction also varies considerably, with many samples being dominated by mud. In comparison to shipboard biostratigraphy, based on core catcher analyses with a depth resolution of ~10 m, we analyzed samples from the two stratigraphic columns every 2-3 m (~45- to 93-k.y. resolution). The placement of planktonic foraminifer zonal boundaries was made at a resolution of ~1.5 m at Site 1146 and ~3.0 m at Site 1143. The higher resolution has resulted in significant changes in biostratigraphic zonal boundary locations compared to shipboard results. […]

本数据集展示了从南海大洋钻探计划（Ocean Drilling Program, ODP）1143与1146站位获取的中新世沉积物样品的生物地层学特征。两个站位获取的浮游有孔虫（planktonic foraminifers）保存状态差异显著，从极差至极佳不等。粒度大于63微米的生物成因沉积物占比同样存在显著差异，多数样品以泥质成分为主。相较于基于岩芯捕集器分析、深度分辨率约10米的船上生物地层学研究，本研究对两个地层柱的沉积物样品以每2-3米的间隔进行分析，对应分辨率约为4.5万至9.3万年。1146站位浮游有孔虫生物地层带边界的厘定分辨率约为1.5米，1143站位则约为3.0米。相较于船上分析结果，本研究采用的更高分辨率分析使得生物地层带边界的位置发生了显著变化。[…]