Geology of the Tomioka Area, Gunma Prefecture, with a note on "Lepidocyclina" from the Abuta Limestone Member

• Main Author: Matsumaru Kuniteru
• Format: Report
• Language: English
• Published: Tohoku University 1967
• Subjects: Planktonic foraminifera
• Online Access: http://hdl.handle.net/10097/28797; https://tohoku.repo.nii.ac.jp/?action=repository_uri&item_id=11994; https://tohoku.repo.nii.ac.jp/?action=repository_action_common_download&item_id=11994&item_no=1&attribute_id=18&file_no=1

The Tertiary System distributed in the area extending from Shimonita-machi to the west of Takasaki City, Gunma Prefecture was studied with the purpose to make a biostratigraphical classification of the different lithological units based upon the Foraminifera (planktonic and benthonic). Emphasis was given to the interpretation of the geostructure, sedimentary environment of the fossiliferous Tertiary strata, geological ages of the stratigraphic units, correlation with other areas and to make a paleontological study on Nephrolepidina from the present area. Descriptions are given to each of the formations recognized in the field, preserved specimens of Nephrolepidina from the Abuta Limestone Member of the Idozawa Formation and the planktonic Foraminifera from several localities of each formation are treated in detail.