Inuwaka, Unakami-gun, Simosa Province: Piacenzian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Rhynchonellata - Terebratulida - Cancellothyrididae
Rhynchonellata - Terebratulida - Terebratulidae
Gryphus radiata Hatai 1936
Gryphus angularis (Hayasaka 1922)
Rhynchonellata - Terebratulida - Laqueidae
Laqueus quadratus Yabe and Hatai 1934
Rhynchonellata - Terebratulida - Dallinidae
see common names

Geography
Country:Japan
Coordinates: 35.7° North, 140.9° East (view map)
Paleocoordinates:35.6° North, 140.2° East (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period: Neogene Epoch: Pliocene
Stage: Piacenzian 10 m.y. bin: Cenozoic 6
Key time interval: Piacenzian
Age range of interval: 3.6 - 2.58 m.y. ago
Stratigraphy
Formation:Naarai
Stratigraphic resolution:group of beds
Stratigraphy comments: From the "Brachiopod-Crevices" which are cut into the Paleozoic rocks. The Inubo Group (of which the Naarai Fm is the basal part) on the Choshi peninsula is composed of marine deposits with a thickness of about 500 m. The depositional age of the group has been estimated at 3.2 Ma to 0.4 Ma from nannofossil biostratigraphy (Nishida 1980; Fujioka & Kameo 2004), magnetostratigraphy (Niitsuma 1970; Sakai 1990), and widespread tephras (Fujioka & Kameo 2004; Tamura et al. 2006). Over 50 tephra beds are intercalated in this group (Sakai 1990; Fujioka & Kameo 2004). Naarai Fm spans the Plio-Pleistocene boundary (ranging from Piacenzian to Gelasian) (Satoguchi & Nagahashi 2012), but this locality is from the lower part.
Lithology and environment
Primary lithology:tuffaceous,blue poorly lithified sandstone
Lithology description: Bluish, soft tuffaceous or sandy rock
Environment:marine indet.
Geology comments: "fairly deep water"
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Metadata
Database number:190821
Authorizer:M. Clapham Enterer:M. Clapham
Modifier:M. Clapham Research group:marine invertebrate
Created:2017-12-18 21:38:43 Last modified:2025-02-22 15:12:02
Access level:the public Released:2017-12-18 21:38:43
Creative Commons license:CC0
Reference information

Primary reference:
64049. K. M. Hatai. 1940. The Cenozoic Brachiopoda of Japan. Science Reports, Tohoku Imperial University, Series 2 20:1-413 [M. Clapham/M. Clapham]