Higashi-Tanakura Group Kubota Fm Molluscan Fauna Locality 17 (Miocene of Japan)

Also known as Locality 17

Where: Japan (37.5° N, 140.0° E: paleocoordinates 38.9° N, 138.4° E)

• coordinate based on political unit

• local area-level geographic resolution

When: Kubota Formation (Higashi-Tanakura Group), Late/Upper Miocene (11.6 - 5.3 Ma)

• Higbashi-Tanajura group is a marine representative of the regressive Genjigawa stage

• formation-level stratigraphic resolution

Environment/lithology: marginal marine; lithified, medium-grained, micaceous, gray, blue, argillaceous sandstone and lithified, fine-grained, micaceous, black, blue, argillaceous sandstone

• Lateral and vertical changes of lithofacies indicate that the group had been accumulated in the course of a local transgression and regression. Sediment is supplied from Abukuma mountain block. Paleogeographically, Higashi-Tanakura group is the deposits filling up a small shallow embayment open to the north.
• massive medium sandstone in the lower part and massive fine sandstone with intercalations of several ash tuff layers in the central and upper part of the basin...characterized by abundant occurrence of molluscan fossils. Bluish-gray medium to fine sandstone covers (beds below) and consists mainly of quartz and mica grains with argillaceous materials. It is fine in the west, and becomes coarser eastward...The medium sandstone is covered by massive fine sandstone in the southern area. This fine sandstone is bluish-black colored, massive, homogeneous, argillaceous and rich in mica flakes. Several white fine ash tuff layers are intercalated in the middle part of the fine sandstone. They are concentrated in three restricted horizons. Coarse sandstone lenses, rich in shell fragments and quartz grains are found at Okada. They are more than 10m in thickness and are contemporaneous with the fine sandstone and diminish laterally into the fine sandstone.

Primary reference: Y. Iwasaki. 1970. The Shiobara-type Molluscan Fauna: An ecological analysis of fossil molluscs. Journal of the faculty of science, University of Tokyo, Section 2 17(3):351-444 [A. Miller/K. Bulinski/K. Bulinski]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 52123: authorized by Arnold Miller, entered by Kate Bulinski on 25.07.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

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Gastropoda
 Cerithioidea - Turritellidae
Turritella tanaguraensis
 Sorbeoconcha - Naticidae
"Neverita kiritaniana" = Glossaulax didyma
"Neverita kiritaniana" = Glossaulax didyma Röding 1798 moon snail
 Neogastropoda - Buccinidae
Neptunea hukusimensis
Bivalvia
 Carditida - Crassatellidae
"Crassatella" cf. pauxilla
 Cardiida - Veneridae
Dosinia japonica, Mercenaria chitaniana
Dosinia japonica venus clam
 Lucinida - Lucinidae
"Lucinoma annulata" = Lucinoma annulatum
"Lucinoma annulata" = Lucinoma annulatum Reeve 1850 clam
 Mytilida - Mytilidae
"Mytilus grayanus" = Crenomytilus grayanus
"Mytilus grayanus" = Crenomytilus grayanus Dunker 1853 mussel
 Pectinida - Pectinoidae
"Pecten (Patinopecten) paraplebejus" = Mizuhopecten paraplebejus, "Chlamys (Miyagipecten) matsumoriensis" = Miyagipecten matsumoriensis, "Chlamys kaneharai" = Mimachlamys kaneharai
"Pecten (Patinopecten) paraplebejus" = Mizuhopecten paraplebejus Nomura and Hatai 1936 scallop
Dominant species at locality
"Chlamys (Miyagipecten) matsumoriensis" = Miyagipecten matsumoriensis Masuda 1952 scallop
"Chlamys kaneharai" = Mimachlamys kaneharai Yokoyama 1926 scallop
 Arcida - Arcidae
Barbatia obtusoides
 Arcida - Glycymerididae
Glycymeris yessoensis
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium yokoyamai