Tuffaceous facies (Tagpochau Limestone), Saipan, Mariana Islands (Miocene of Northern Mariana Islands)

Where: Northern Mariana Islands (15.2° N, 145.8° E: paleocoordinates 15.2° N, 148.0° E)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Tagpochau Formation, Early/Lower Miocene (23.0 - 16.0 Ma)

• The Tagpochau Limestone is a complex of calcareous clastic rocks that integrade with one another. The limestone appears to span the Indonesian Tertiary e interval or early Miocene age. Six lithic facies and two members are recognized in the Tagpochau Limestone, and include: 1) Donni Sandstone Member; 2) Machegit conglomerate Member; 3) transitional facies of calcareous tuff and marl; 4) TUFFACEOUS LIMESTONE FACIES; 5) limestone facies; 6) rubbly limestone facies; 7) equigrannular limestone facies; 8) inequigranular limestone facies. The collection is from the Donni Sandstone member occurs near the middle of the formation.

• group of beds-level stratigraphic resolution

Environment/lithology: poorly lithified, tuffaceous, shelly/skeletal, brown limestone

• No paleoenvironmental data reported.
• Tuffaceous, poorly indurated, very impure limestones; impure limestone, locally fossiliferous, well-bedded and locally cross-bedded, for the most part poorly indurated, reddish brown to darkish orange-brown.

Size class: macrofossils

Collection methods: quarrying,

• Collections probably reposited in USNM collections, but this is not stated.

Primary reference: P. E. Cloud, Jr, R.G. Schmidt, and H.W. Burke. 1956. Geology of Saipan, Mariana Islands: Part 1. General Geology. United States Geological Survey Professional Paper 280(A):1-126 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 43365: authorized by Austin Hendy, entered by Austin Hendy on 12.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca, echinoidea, corals, and calcareous algae are also included. Foraminifera are listed but not included in collection. Identifications of mollusca by J. Gardner, echinoids by C.W. Cooke, corals by J.W. Wells.
Bivalvia
 Pectinida - Pectinoidae
"Chlamys (Aequipecten) exageratus" = Aequipecten
"Chlamys (Aequipecten) exageratus" = Aequipecten scallop
 Cardiida - Tellinidae
Tellina ? sp. Linnaeus 1758 tellin clam
 Cardiida - Cardiidae
Tridacna sp. Bruguière 1797 cockle
Gastropoda
 Opisthobranchia - Bullidae
Bulla reussi Martin 1879 snail
 Neogastropoda - Conidae
Conus sp. Linnaeus 1758 cone shell
 Neogastropoda - Terebridae
"Terebra (Strioterebrum) indica" = Terebra (Myurella) indica
"Terebra (Strioterebrum) indica" = Terebra (Myurella) indica Martin 1879 auger snail
 Stromboidea - Strombidae
Strombus sp. Linnaeus 1758 conch
 Cypraeoidea - Cypraeidae
Cypraea sp. Linnaeus 1758 cowry
 Tonnoidea - Cassidae
"Cassis" sp. Scopoli 1777 snail
 Sorbeoconcha - Turritellidae
"Turritella sedanensis" = Haustator sedanensis
"Turritella sedanensis" = Haustator sedanensis Martin 1905 turret shell
Echinoidea
 Camarodonta - Echinometridae
Echinostrephus sp. n. sp. sea urchin