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
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Latirulus cf. cracticulatis
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Gastropoda
- Cerithiidae
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Cerithium (Thericium) echinatum
Lamarck 1822
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Gastropoda
- Trochidae
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Trochus calcaratus
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Gastropoda
- Turbinidae
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Marmorostoma (Batillus) cf. cornuta
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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] |