Middle Eocene to early Oligocene planktonic and benthic foraminifers from ODP Hole 125-786A

Drilling at Site 786, located in the center of the Izu-Bonin forearc basin, penetrated an apparently continuous section of middle Eocene/lower Oligocene volcaniclastic breccias and nannofossil oozes. Planktonic foraminiferal faunas underwent a gradual transition from relatively high-diversity middle Eocene through late Eocene tropical or warm-water assemblages to a cooler-water, less diverse assemblage during the early Oligocene. […]对位于伊豆-小笠原弧前盆地（Izu-Bonin forearc basin）中部的786站位开展的钻探，钻遇了一套近乎连续的中始新世/渐新世早期火山碎屑角砾岩与超微化石软泥（nannofossil oozes）。浮游有孔虫动物群（planktonic foraminiferal faunas）呈现出逐步演替的特征：从中始新世到晚始新世相对高多样性的热带/暖水组合，逐渐过渡至渐新世早期冷水、低多样性的组合。[…]