Estacao Agronomica - Bed 8 (Estacao Lmst.) (Miocene of Brazil)

Where: Para, Brazil (1.0° S, 48.0° W: paleocoordinates 1.0° S, 43.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Estacao Limestone Member (Pirabas Formation), Early/Lower Miocene (23.0 - 16.0 Ma)

• Collection from "bed 8" within the limestone unit. No description of the section is given so this collection cannot be placed in a stratigraphic framework. Fauna not very much like that of the Rio Pirabas outcrop, although many species are in common. Molluscan fauna indicate a Lower Miocene age. The deposit is stratigraphically near to the Pirabas Formation, but paleontological evidence is insufficient for an exact correlation. Maury (1924) suggested that it could be synchronous, slightly younger or slightly older. No specimens of Orthaulax have been ound in the fauna, suggesting a younger age, perhaps equivalent to the Gatun Fm. Simone (1994) does not illustrate any other Miocene units in the Parnaiba Basin other than the Pirabas Formation, for which I conclude the Estacao Limestone must now be considered a member of. The Pirabas Fm has a latest Late Oligocene to Middle Miocene age according text. Early Miocene in Vokes (1990), and is accordingly assigned to Early Miocene here.

• bed-level stratigraphic resolution

Environment/lithology: lithified, fine-grained, shelly/skeletal, gray, calcareous limestone

• No environmental data reported.
• Fine-grained, light gray limestone. Otherwise fine-grained, generally grayish limestone, composed of finely ground sediments, including imperfectly preserved molluscan shells and bryozoan colonies. The limestone is highly calcareous.

Size class: macrofossils

Preservation: cast, mold/impression

Collection methods: quarrying,

• Artificial casts of the external molds were made. Collected by F. de Carvalho and Dr. Gonzaga for G. de Campos of the Brazil Geological Survey. Types are reposited at the Museum of the Brazil Geological Survey.

Primary reference: C. J. Maury. 1924. Fosseis Terciarios Do Brazil. Servico Geologico E Mineralogico Do Brazil Monographia 49 [A. Miller/A. Hendy/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 60984: authorized by Austin Hendy, entered by Austin Hendy on 28.05.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• Fairly lengthy list, but possibly not exhaustive given the quality of the fauna. The nomenclature is antiquated, though has species-resolution assignments; identifications by Maury who had extensive knowledge of circum-Caribbean faunas.
 Cheilostomata - Lunulitidae
 Arcida - Arcidae
"Scapharca ? melloi" = Scapharca (Cunearca) melloi
"Scapharca ? melloi" = Scapharca (Cunearca) melloi Maury 1924 ark
 Pectinida - Plicatulidae
 Cardiida - Solecurtidae
"Psammosolen cereris" = Solecurtus cereris
"Psammosolen cereris" = Solecurtus cereris Maury 1924 clam
 Cardiida - Tellinidae
"Macoma cf. riopirabica" = Macoma (Psammacoma) riopirabica Maury 1924 tellin clam
 Cardiida - Cardiidae
"Cardium (Trachycardium) coutinhoi n. sp." = Trachycardium
"Cardium (Trachycardium) coutinhoi n. sp." = Trachycardium cockle
Resembles: C. paraense
 Cardiida - Veneridae
Callocardia sp., "Clementia brasiliana n. sp." = Clementia (Clementia) dariena
Callocardia sp. Adams 1864 venus clam
"Clementia brasiliana n. sp." = Clementia (Clementia) dariena Conrad 1855 venus clam
 Sorbeoconcha - Turritellidae
Turritella callizona turret shell
 Neogastropoda - Turridae
"Pleurotoma barretti" = Polystira barretti
"Pleurotoma barretti" = Polystira barretti Guppy 1866 turrid
 Neogastropoda - Conidae
Conus longesperatus n. sp. cone shell
Close ally of: C. tortuosostriatus; complete specimen