Middle Miocene to Pleistocene radiolarian biostratigraphy in the Northwest Pacific Ocean, ODP Leg 186
Middle Miocene to Pleistocene radiolarian biostratigraphy in the Northwest Pacific Ocean, ODP Leg 186
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DOI：
10.1111/j.1440-1738.2003.00421.x
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发表时间：
2004-03
期刊：
影响因子：
1.5
通讯作者：
S. Kamikuri;H. Nishi;I. Motoyama;S. Saito
中科院分区：
文献类型：
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作者：
S. Kamikuri;H. Nishi;I. Motoyama;S. Saito
摘要 在海洋钻探计划第 186 段的 1150 和 1151 号地点钻探的上新生代沉积层序，使得能够在日本北部群岛弧前区域建立放射虫分区和生物事件年龄校准。这些序列被分为从更新世 Botryostrobus aquilonaris 区域到 1150 号站点上中新世 Lipmanella redondoensis 区域的 9 个区域，以及从更新世 Stylatractus universus 区域到中中新世 Dendrospyris 区域的 11 个区域。 1151号站点的堺井带。这些区域成功地与西北太平洋许多深海岩心的研究序列以及日本陆上的一些区域进行了关联。在研究期间识别的 67 个重要的放射虫生物事件中，29 个更新世至上中新世事件通过明确的古地磁极性记录与地磁极性时间尺度直接相关，21 个上中新世事件根据硅藻生物地层学进行了校准。在这些事件中，选择了 24 个地理广泛的事件来测试西北太平洋中高纬度时间范围的同步性和有用性，涉及其他 8 个近海和陆上部分。检查表明，大多数地带性边界事件在所考虑的区域内是同步的，并且许多历时事件（其中大部分已从地带性方案中消除）是与该物种的罕见和零星发生有关的不可靠事件。研究岩心的放射虫生物地层学清楚地表明了中更新世、晚中新世和中中新世晚期的三个主要间断。后两个间断可以分别与两个全球海洋间断 NH6 和 NH3 相关。
Abstract The Upper Cenozoic sedimentary sequences drilled at Sites 1150 and 1151, Ocean Drilling Program Leg 186, enabled establishment of radiolarian zonation and calibration of the age of bioevents in the forearc area of the northern Japan Islands. The sequences were divided into nine zones from the Pleistocene Botryostrobus aquilonaris Zone to the Upper Miocene Lipmanella redondoensis Zone at Site 1150, and 11 zones from the Pleistocene Stylatractus universus Zone to the Middle Miocene Dendrospyris? sakaii Zone at Site 1151. These zones correlate successfully with the studied sequences of many of deep‐sea cores in the Northwest Pacific Ocean and with some sections of onshore Japan. Of 67 important radiolarian bioevents recognized during the study, 29 Pleistocene to Upper Miocene events were directly tied to the geomagnetic polarity time scale through the well‐defined paleomagnetic polarity records, and 21 Upper Miocene events were calibrated based on the diatom biostratigraphy. Of these events, 24 geographically widespread events were selected to test synchroneity and usefulness as time‐horizons within the mid‐to‐high latitude of the Northwest Pacific, involving eight other offshore and onshore sections. Examination showed that most of the zonal boundary events are synchronous within the considered region, and that many diachronous events, most of which are eliminated from the zonal scheme, are unreliable events linked to rare and sporadic occurrences of the species. Radiolarian biostratigraphy of the studied cores clearly indicates three major hiatuses in the Middle Pleistocene, Late Miocene and late Middle Miocene. The latter two hiatuses can be correlated to two global oceanic hiatuses, NH6 and NH3, respectively.