Estacao Agronomica - Bed 5 (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 5" 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.
• Purer, hard and compact, moldic 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 60981: 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 sp. Gray 1847 clam
 Cardiida - Cardiidae
"Cardium (Trachycardium) cf. coutinhoi" = Trachycardium
"Cardium (Trachycardium) cf. coutinhoi" = Trachycardium cockle