Unified stratigraphy by means of Oxygen isotopes and microfossils for Paleozoic-Mesozoic siliceous deposits

本项目旨在通过放射虫等微化石和氧同位素地层学统一生物地层学。该项目最重要的议程是组成激光微探针分析仪，该分析仪由激光单元和氧气净化线组成。该分析仪已在项目期限结束时完成，因为与旧建筑的更新和新建筑的建设有关的两次移动。然而，新建立的分析仪比原来计划的要有用得多，因为它不仅产生氧同位素，还产生硅同位素。在新潟大学的分析仪建立之前，日本地质调查局使用激光微探针分析仪测量了ODP Leg 129期间从太平洋获得的深海硅质矿床的氧同位素。初步结果表明，通过氧同位素和放射虫的分析，上侏罗统—下白垩统地层已成功统一。在日本西南部米诺和Chichibu地区进行了放射虫生物地层学和微古生物学研究。放射虫古生物学和地层学的科学成果来自中国藏南和菲律宾北巴拉望地块。在欧洲阿尔卑斯山脉的瑞士、意大利和斯洛文尼亚，系统地收集了上古生物硅质岩。这些样品将在不久的将来用于氧和硅的同位素测量。

This project aims at unifying biostratigraphy by means of microfossils such as radiolarians and Oxygen isotope stratigaphy. The most important agenda for this project was to make up a laser microprobe analyzer composed of a laser unit and Oxygen purification lines. The analyzer has been completed at the end of the project term due to twice moves in connection to the renewal of an old building and the construction of a new building. However, the newly established analyzer is much more useful than originally planed because it produces not only Oxygen isotopes but also Silicon isotopes.Oxygen isotopes of deep sea siliceous deposits obtained from the Pacific during ODP Leg 129 were measured by using a laser microprobe analyzer in the Geological Survey of Japan before the analyzer in Niigata University was set up. A preliminary result indicates that Upper Jurassic to Lower Cretaceous stratigraphy by means of Oxygen isotope and radiolaria is successfully unified.Radiolarian biostratigraphic and micropaleontologic researches were carried out in the Mino and Chichibu Terranes, Southwest Japan. Scientific results on radiolarian paleontology and stratigraphy came from Southern Tibet in China and the North Palawan Block in the Philippines. Pelagic biogenic siliceous rocks have been collected systematically from Switzerland, Italy and Slovenia in the European Alps. These samples will be used for Oxygen and Silicon isotope measurements in the near future.