USGS 17545 - Yontan Limestone, Ryukyu Group, Okinawa: Early/Lower Pleistocene, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Neogastropoda - Fasciolariidae
Latirulus cf. cracticulatis
Gastropoda - Cerithiidae
Cerithium (Thericium) echinatum Lamarck 1822
Gastropoda - Trochidae
Trochus calcaratus
Gastropoda - Turbinidae
Marmorostoma (Batillus) cf. cornuta
see common names

Geography
Country:Japan State/province:Okinawa
Coordinates: 26.4° North, 127.7° East (view map)
Paleocoordinates:26.5° North, 127.5° East
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period:Quaternary Epoch:Pleistocene
10 m.y. bin:Cenozoic 6
Key time interval:Early/Lower Pleistocene
Age range of interval:2.58800 - 0.78100 m.y. ago
Stratigraphy
Geological group:Ryukyu Member:Yontan Limestone
Stratigraphic resolution:bed
Stratigraphy comments: The Yontan Limestone is the upper part of the Ryukyu Limestone. Some parts of the Yontan Limestone have a tecture similar to parts of the Naha Limestone, but in general the Yontan is coarser. Locally it consists of unsorted detrital fragments up to a foot in dimension. None of the fragments can be identified as Naha Limestone. The rock is highly porours to dense. The greatest observed thickness of the Yontan Limestone is about 200 ft, elsewhere the greatest thickness is around 40 ft. The Yontan Limestone rests on Paleozoic rocks, on beds of the Shimajiri Fm, or on the Naha Limestone. Its contact with the later is a wavy erosional discontinuity.
Lithology and environment
Primary lithology:coarse poorly lithified conglomeratic "limestone"
Includes fossils?Y
Lithology description: Limestone, though coarser than that of the Naha. Locally it consists of unsorted detrital fragments up to a foot in dimension
Environment:carbonate indet.
Glacial or sequence phase:transgressive
Geology comments: Shallow water carbonate environment? No specific paleoenvironmental data provided.
Taphonomy
Modes of preservation:body,original aragonite
Size of fossils:macrofossils
Collection methods and comments
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:Exhaustive for gastropoda. No bivalves.
Metadata
Also known as:WF 236
Database number:42354
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Created:2004-07-28 09:31:18 Last modified:2013-11-25 13:37:23
Access level:the public Released:2004-07-28 09:31:18
Creative Commons license:CC BY
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]