@article{oai:soar-ir.repo.nii.ac.jp:00012098, author = {久保田, 正史 and 小坂, 共栄}, issue = {1}, journal = {信州大学理学部紀要}, month = {Oct}, note = {The Kato Mountain Range, which lies north of the Uchimura Mountain Range, is underlain by greenish altered volcanic rocks and sedimentary rocks of lower to middle Miocene age. Geologic sections of this area subdivided into following formations in ascending order, such as the Omineyama, Taroyama, Yokoo and Iseyama Formations (Yamagishi, 1964). In this paper the author report the planctonic foraminifers found in the Yokoo Formation. Planctonic foraminifers in the Yokoo Formation are characterized by follwing species, such as Globigerina angustiumbilicata BOLLI, Gg. bulloidea d' ORBIGNY, Gg. eamesi BLOW, Gg. falconensis BLOW, Gg. praebulloides BLOW, Gg. woodi JENKINS, Gg. sp., Globorotalia maeri CUSHMAN and ELLISOR, Gg. peripheroronda BLOW and BANNER, Gr. praescitula BLOW, Gr. sp., Globigerinoides immaturus LEROY, Gs. sicanus DE STEFANI, Gs. subquadratus BRONNIMANN, Gs. triloba (EGGER), Globigerinella praesiphonifera (BLOW), Globoquadrina dehiscens (CHAPMAN, PARR and COLLINS), Sphaeroidinellopsis (FINLAY), Ss. seminulina seminulina (SCHWAGER), Praeorbulina glomerosa circularis (BLOW), Orbulina universa d' ORBIGNY. From these facts it is concluded that the Yokoo Formation can be assigned to planctonic foraminiferal zones N. 8~9., Article, 信州大学理学部紀要 25(1): 35-42(1990)}, pages = {35--42}, title = {北部フォッサマグナの新第三系横尾層から産出した浮遊性有孔虫化石}, volume = {25}, year = {1990} }