USGS 17442 - Chinen Sand Member, Ryukyu Group, Okinawa (Pliocene of Japan)

Also known as MD 25

Where: Okinawa, Japan (26.3° N, 127.9° E: paleocoordinates 26.6° N, 127.4° E)

• coordinate estimated from map

• outcrop-level geographic resolution

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

• Fine gray sand. 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 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.
• Fine gray sand

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 42229: 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
unclassified
  -
Gastropoda
 Trochoidea - Trochidae
 Cerithioidea - Turritellidae
Turritella filiola turret shell
 Neogastropoda - Mitridae
Mitra (Cancilla) filaris Linnaeus 1771 mitre shell
Mitra (Cancilla) cf. flammea Quoy 1832 mitre shell
 Neogastropoda - Nassariidae
 Neogastropoda - Fasciolariidae
 Neogastropoda - Columbellidae
 Neogastropoda - Clavatulidae
 Neogastropoda - Conidae
Conus aff. virgo Linnaeus 1758 cone shell
 Neogastropoda - Clathurellidae
 Neogastropoda - Turridae
 Neogastropoda - Costellariidae
 Neogastropoda - Muricidae
Typhis arcuatus murex snail
 Sorbeoconcha - Tonnidae
 Sorbeoconcha - Ranellidae
"Cymatium (Limatella) cingulatum" = Linatella caudata
"Cymatium (Limatella) cingulatum" = Linatella caudata Gmelin 1791 triton shell
 Sorbeoconcha - Ovulidae
Volva (? Pellasimnia) sp. Iredale 1931 snail
 Sorbeoconcha - Naticidae
Polinices albumen Linnaeus 1758 moon snail
Mammilla melanostoma Gmelin 1791 moon snail
Tanea undulata Röding 1798 moon snail
Natica cf. vitellus Linnaeus 1758 moon snail
 Heterostropha - Architectonicidae
"Architectonica maxima" = Architectonica (Architectonica) maxima Philippi 1849 sundial
Architectonica perspectiva Linnaeus 1767 sundial