Shinzato Tuff, Shimajiri Formation, Okinawa: Late Miocene - Early Pliocene, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
unclassified
see common names

Geography
Country:Japan State/province:Okinawa
Coordinates: 26.5° North, 127.5° East (view map)
Paleocoordinates:
Basis of coordinate:estimated from map
Geographic resolution:basin
Time
Period: Neogene Epoch: Miocene - Pliocene
10 m.y. bin: Cenozoic 6
Key time interval: Late Miocene - Early Pliocene
Age range of interval: 11.63 - 3.6 m.y. ago
Stratigraphy
Formation:Shimajiri Member:Yonabaru Clay
Regional section:Okinawa
Stratigraphic resolution:formation
Stratigraphy comments: The uppermost part of the Shimajiri Formation. The Shinzato is fairly homogeneus, consisting for the most part of sandyy or silty clays with minor partings of ash. Its color ranges from dark gray to light gray. Its maximum known thickness is about 200 ft. The base of the formation is characterized by conglomeratic pumice, and in places chanels cut into the Yonabaru Clay Member.
Lithology and environment
Primary lithology:tuffaceous,gray silty,sandy claystone
Includes fossils?Y
Lithology description: Consists for the most part of sandy or silty clays with minor partings of ash. Its color ranges from dark gray to light gray.
Environment:deep-water indet.
Glacial or sequence phase:transgressive
Geology comments: Molluscs found in assemblages of the Shinzato Tuff Member occur in depths as much as 300 m, although some can be in shallower water. Generally the assemblage should be regarded as deep-water.
Taphonomy
Modes of preservation:body,original aragonite
Size of fossils:macrofossils
Collection methods and comments
Collection excludes:some macrofossils
Collection methods:selective quarrying,field collection
Reason for describing collection:taxonomic analysis
Collection method comments: Collections held in USNM and UGSG repositories.
Taxonomic list comments:Taxa described in text, but not listed for specific localities. Importantly this list contains bivalvia
Metadata
Database number:42389
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Created:2004-07-28 14:26:16 Last modified:2025-02-22 15:12:02
Access level:the public Released:2004-07-28 14:26:16
Creative Commons license:CC0
Reference information

Primary reference:
7337. F. S. MacNeil. 1960. Tertiary and Quaternary Gastropoda of Okinawa: A comparison of the late Miocene, Pliocene, and Pleistocene Gastropoda of Okinawa with related faunas of East Asia together with a resume of the geological setting of the fossiliferous deposits. United States Geological Survey Professional Paper 339:1-148 [A. Miller/C. Ferguson/P. Wagner]