Pliocene and Pleistocene diatom datum levels of the Northwest Pacific ...

• Main Author: Koizumi, Itaru
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1986
• Subjects: Drilling/drill rig; Composite Core; Leg86; Glomar Challenger; Deep Sea Drilling Project DSDP; Pacific; Subarctic
• Online Access: https://dx.doi.org/10.1594/pangaea.690404; https://doi.pangaea.de/10.1594/PANGAEA.690404

Thick sections of Pliocene and Pleistocene biosiliceous clay and ooze were recovered by the Hydraulic Piston Corer (I-IPC) at three northwest Pacific sites (DSDP Sites 578, 579, and 580). They contain a well-preserved paleomagnetic record which made it possible to evaluate diatom events used in low and high latitudes in the transitional region of the northwest Pacific. Equatorial Pacific events are usually isochronons between the equatorial and subarctic regions. However, species which have short ranges in low latitudes tend to have diachronous first and last appearances in higher latitudes. All subarctic North Pacific datum species are present in the sediments at three sites which lie north and south across the subarctic front, but their ranges become shorter in southern regions. They do not penetrate into the equatorial region. Spatial distributions of these events are influenced by the paleo-position of the subarctic front. The migration of species from their home-area outwards, in the form of the first ... : Supplement to: Koizumi, Itaru (1986): Pliocene and Pleistocene diatom datum levels related with paleoceanography in the northwest Pacific. Marine Micropaleontology, 10(4), 309-325 ...