Time and space distribution of the Japanese Cenozoic molluscan type specimens based on the integrated biostratigraphy

为了弄清日本新生代软体动物的时空分布，主要采用生物地层学和K-Ar法、FT法等同位素测年方法，对包括模式种在内的各地层进行了精确的年代学研究。我们研究了北海道、日本东北部、日本中部、日本西南部、九州和冲绳的新生代地层的地质时代。并整理了近10年来发表的有关地层地质时代和地质对比资料的论文。据此，提出了新的新生代软体动物生物地层划分方案，并将其发表在2008年8月出版的《第9届太平洋新第三纪地层学会议录》（日本地质调查局公报特刊）上，从生物年代学角度对日本古近纪动物群进行了编制，将中新世软体动物群划分为亚热带Akeyo-Kunugidaira动物群（20-16. 4 Ma），热带和/或亚热带八尾-角野 ...更多信息 萨瓦动物群（16. 4-15. 3 Ma），亚热带和/或暖温带Moniwa动物群（15. 3-15 Ma）、暖温带的古老盐原-山动物群（15-11 Ma）和中温带和/或冷温带的新盐原-山动物群（11-5 Ma）。3 Ma）。这些动物群可以被认为是从热带到冷温带地区的逐步冷却阶段的响应。Kukinaga动物群是早中新世Vicarya-bearing动物群的遗迹，以Arabi-Potamidid动物群为特征。然而，我们再次尝试了微体化石生物地层学的库库纳加群，它仍然是继续调查。此外，还对主要分布于关东地区的祖师软体动物群进行了生物年代学研究，并根据钙质超微化石生物地层学确定其时代为中新世晚期，从而结合日本海裂谷的发展过程，编制了日本列岛详细的新生代地质和古生物史。少

In order to clarify the time and space distribution of the Japanese Cenozoic molluscan species, we have been investigated precise age of each strata which including the type species mainly based on the integrated biostratigraphy and isotopic age such as K-Ar and FT method. We studied the geologic age of Cenozoic strata of Hokkaido, NE Japan, Central Japan, SW Japan, Kyushu and Okinawa Islands., and also compiled published papers described data on the geological age of strata and geologic correlation during the last 10 years. As a result, we can proposed new Cenozoic molluscan biostratigraphical scheme, which will be published in the proceedings of the 9th Pacific Neogene Stratigraphy in August, 2008 (Special issue of the Bulletin of Geological Survey of Japan).Japanese Paleogene faunas have been compiled from the biochronological aspect, and Miocene molluscan faunas are now divided into the subtropical Akeyo-Kunugidaira fauna (20-16. 4 Ma), the tropical and/or subtropical Yatsuo-Kadono … More sawa fauna (16. 4-15. 3 Ma), the subtropical and/or warm temperate Moniwa fauna (15. 3-15 Ma), the warm-temperate Older Shiobara-Yama fauna (15-11 Ma) and the mild-temperate and/or cool-temperate Younger Shiobara-Yama fauna (11-5. 3 Ma). These faunas can be considered as responses to stepwise cooling stages from tropical to cool-temperate realms, respectively. The Kukinaga fauna, characterized by Arcid-Potamidid fauna, is considered as a relict of the Vicarya-bearing early Miocene fauna. However, we tried once again microfossil biostratigraphy for the Kukunaga Group, and it is still continue to investigate. In addition, we studied the Zushi molluscan fauna which distributed mainly around the Kanto area from the biochronological aspect and concluded it is late Miocene in age based on calcareous nannofossil biostratigraphy.Consequently, we compiled detailed Cenozoic geological and paleoenvironmtal history of the Japanese Islands in conjunction with the developmental process of the rifting of the Japan Sea. Less