USGS 17479 - Chinen Sand Member, Ryukyu Group, Okinawa (Pliocene of Japan)

Also known as TKRS 7

Where: Okinawa, Japan (26.4° N, 128.0° E: paleocoordinates 26.7° N, 127.4° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Chinen Sand Member, Early/Lower Pliocene (5.3 - 3.6 Ma)

• Lower sand units were formely included in the Shimajiri beds, but they are disconformable with the underlying Shimajiri Formation. The lower sandy and silty part of the Ryukyu Group is divided into two elements, the Nakoshi Sand and the Chinen Sand. Presumably the two members are equivalent in age, but they are laterally not related. The Chinen sand is light gray to dark gray and more uniformely fine than the Nakoshi, and can have fine silt partings.

• bed-level stratigraphic resolution

Environment/lithology: marine; unlithified, fine-grained, gray, silty sandstone

• Probably reworked Shimajiri material during a transgression. Its deposition was followed immediately by a period during which reefs flourished and large ares were strewn with reef detritus.
• Light gray to dark gray, uniformely fine, can have fine silt partings.

Size class: macrofossils

Preservation: original aragonite

Collection methods: quarrying,

• Collections held in USNM and UGSG repositories.

Primary reference: 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]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 42238: authorized by Austin Hendy, entered by Austin Hendy on 26.07.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for gastropoda. No bivalves.
 Neogastropoda - Turridae
 Tonnoidea - Tonnidae