Neogene Radiolarians from the Kerguelen Plateau

Abundant, generally well-preserved radiolarians from Sites 737, 744, 745, 746, 747, 748, and 751 were used in stratigraphic analysis of Neogene, and particularly middle Miocene to Holocene, Kerguelen Plateau sediments. The composite Kerguelen section is more complete than the Weddell Sea sections recovered by Leg 113, and the radiolarians are better preserved. Leg 113 radiolarian zonations of Weddell Sea sites were applicable with only slight modification, and three new zones - Siphonosphaera vesuvius, Acrosphaeral labrata, and Amphymenium challengerae - are proposed for the latest Miocene. Geologic age estimates are given for all radiolarian zones used. Major hiatuses affecting most sites were seen within the middle Miocene, in the latest Miocene, and latest Pliocene. Five new species are described: Acrosphaera? labrata, Acrosphaera? mercurius, Siphonosphaera vesuvius, Actinomma? magnifenestra, and Helotholus? haysi.

本次研究使用采自737、744、745、746、747、748及751站位的丰富且保存状态良好的放射虫（radiolarians），开展凯尔盖朗海台（Kerguelen Plateau）新近纪（Neogene，尤其中中新世至全新世）沉积物的地层分析。复合凯尔盖朗剖面相较于第113航次（Leg 113）在威德尔海（Weddell Sea）获取的沉积物剖面更为完整，且放射虫的保存质量更优。第113航次威德尔海站位的放射虫带划分方案仅需小幅调整即可适配本研究，同时本文为晚中新世地层提出3个新放射虫带：维苏威管球虫（Siphonosphaera vesuvius）带、唇饰顶球虫（Acrosphaera labrata）带以及查林杰双膜虫（Amphymenium challengerae）带。所有纳入本次研究的放射虫带均已给出对应的地质年龄估算值。多数站位均可见发育于中中新世、晚中新世以及上新世最晚期的主要沉积间断。本文还描述了5个放射虫新物种：顶球虫属？唇饰种（Acrosphaera? labrata）、顶球虫属？墨丘利种（Acrosphaera? mercurius）、维苏威管球虫（Siphonosphaera vesuvius）、辐杆虫属？大窗种（Actinomma? magnifenestra）以及盔球虫属？海斯种（Helotholus? haysi）。