ZachahĂșn Corehole - 770 ft (Subibaja Fm) (Miocene of Ecuador)

Also known as Z-770

Where: Guayas, Ecuador (2.3° S, 80.4° W: paleocoordinates 3.5° S, 76.3° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Saiba Member (Subibaja Formation), Early/Lower Miocene (23.0 - 16.0 Ma)

• From Saiba Mbr of Subibaja Fm, which is of lower Early Miocene age, overyling the Dos Bocas Shale (Oligocene) and underlying the Zacachun Mbr of the Subibaja Fm and the Middle Miocene Progresso Fm. The thickness of the formation is 1800 ft at its type section. Age is approximately equivalent to the Burdigalian stage based on correlation with other S. and C. American faunas. It is regionally correlated with the Lower Zorritos (Peru) and Angostura (Ecuador) formations.

• bed-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, gray, sandy siltstone

• Deep-water siliciclastic facies of typically tropical composition.
• Siltstone, massive, dark gray, locally hard with calcareous cement, usually containing numerous foraminifera, garding into shaly and sandy facies.

Size class: macrofossils

Reposited in the PRI

• Fossil material derived from the International Ecuadorian Petroleum Company (subsidiary of Standard Oil Co.) and was collected by the author (then employed by oil company) during field exploration and drilling operations. All type and voucher material reposited in PRI collections.

Primary reference: J. G. Marks. 1951. Miocene stratigraphy and paleontology of Southwestern Ecuador. Bulletins of American Paleontology 33(139):1-448 [A. Miller/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 60721: authorized by Austin Hendy, entered by Austin Hendy on 21.05.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for gastropoda and bivalvia.
Bivalvia
 Nuculanida - Nuculanidae
Nuculana saibana pointed nut clam