Naha Limestone, Ryukyu Group, Okinawa (Pliocene of Japan)

Where: Okinawa, Japan (26.5° N, 127.8° E: paleocoordinates 26.7° N, 127.4° E)

• coordinate estimated from map

• basin-level geographic resolution

When: Naha Limestone Member, Late/Upper Pliocene (3.6 - 2.6 Ma)

• The lower part of the Riukiu Limestone is called the Naha Limestone. It is of Pliocene age and is seperated from the overlying Yontan Limestone (Pleistocene) by an erosional boundary. The Naha Limestone is not a homogeneous lithologic unit. Most of it is poorly indurated medium to coarse grained lime sand, but other parts of it range from a powdery limestone to a dense nonporous limestone. It ranges in color from nearly white to brownish yellow.

• formation-level stratigraphic resolution

Environment/lithology: lagoonal or restricted shallow subtidal; poorly lithified, brown, yellow, calcareous grainstone and poorly lithified, brown, white limestone

• Probably is a reef limestone, but only coral rich in a few places. It is presumed that the Naha Limestone is a detrital lagoon deposit or a reef detritus deposited on an insular shelf. The lower part is more widespread that the upper part, probably reflecting erosion during deposition of the Yontan Limestone. The highest beds are less conglomeratic and generally contain abundant algal nodules.
• Poorly indurated medium to coarse grained lime sand, but other parts of it range from a powdery limestone to a dense nonporous limestone. It ranges in color from nearly white to brownish yellow.

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 42383: authorized by Austin Hendy, entered by Austin Hendy on 28.07.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Taxa described in text, but not listed for specific localities. Importantly this list contains bivalvia
Bivalvia
 Arcida - Arcidae
Bentharca sp. Verrill and Bush 1898 clam
Once referred to as Pseudogramatodon pacificus.....an unlikely ID according to MacNeil (1960)
 Ostreida - Gryphaeidae
"Ostrea musashiana" = Neopycnodonta musashiana
"Ostrea musashiana" = Neopycnodonta musashiana Yokoyama 1920 oyster
 Pectinida - Pectinoidae
"Pecten (Amussiopecten) praesignis" = Amussiopecten praesignis, Pecten byoritzuensis, Chlamys satoi
"Pecten (Amussiopecten) praesignis" = Amussiopecten praesignis Yokoyama 1922 scallop
Chlamys satoi Yokoyama 1928 scallop
Malacostraca
 Decapoda - Callianassidae
Neocallichirus sp. Sakai 1988 decapod
 Decapoda - Macrophthalmidae
"Macrophthalmus (Euplax) latreillei" = Macrophthalmus latreillei, "Macrophthalmus (Euplax) granulosus" = Macrophthalmus latreillei
"Macrophthalmus (Euplax) latreillei" = Macrophthalmus latreillei Desmarest 1822 crab
"Macrophthalmus (Euplax) granulosus" = Macrophthalmus latreillei Desmarest 1822 crab
 Decapoda - Portunidae
Podophthalmus vigil Fabricius 1798 periscope crab
 Decapoda - Leucosiidae
Myra fugax Fabricius 1798 fleeting purse crab