Marks (1951) IPC# 1457 (Blue Siltstone Mbr, Daule Fm) (Miocene of Ecuador)

Where: Guayas, Ecuador (1.7° S, 80.3° W: paleocoordinates 2.5° S, 77.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Blue Siltstone Member (Daule Formation), Middle Miocene (16.0 - 11.6 Ma)

• From Daule Fm, which is of Middle Miocene age comprises three members, a "basal calcareous" member, a middle "blue siltstone" member, and an "upper calcareous" member. The exact thickness of the unit has not been measured accurately in this section because of structural complications. The blue siltstone, from which this collecion is derived is about 800 ft thick. Faunal compositions suggests a Middle Miocene age, with affinities to the Progreso Fm, and Middle Miocene formations of Peru. Taxa are share with the Gatun fm, the Tubera Fm, the Cucurrupi Fm of Colombia.

• bed-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, blue siltstone

• Deposition at slightly greater depth, quiet conditions, several kilometers from shore, siliciclastic environment, with normal salinity conditions, during relative highstand.
• Recessive blue siltstone

Size class: macrofossils

Reposited in the PRI

Collection methods: quarrying,

• 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 61080: authorized by Austin Hendy, entered by Austin Hendy on 29.05.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for gastropoda and bivalvia.
Gastropoda
 Cerithioidea - Potamididae
 Sorbeoconcha - Naticidae
"Natica guppyana" = Stigmaulax guppiana
"Natica guppyana" = Stigmaulax guppiana Toula 1909 moon snail
 Neogastropoda - Cancellariidae
 Neogastropoda - Buccinidae
 Neogastropoda - Terebridae
"Terebra cf. cucurrupiensis" = Terebra (Panaterebra) cucurrupiensis
"Terebra cf. cucurrupiensis" = Terebra (Panaterebra) cucurrupiensis Oinomikado 1939 auger snail
 Neogastropoda - Conidae
"Conus multiliratus" = Conasprelloides multiliratus
"Conus multiliratus" = Conasprelloides multiliratus Olsson 1922 cone shell
 Heterostropha - Architectonicidae
Architectonica nobilis Röding 1798 sundial
Bivalvia
 Nuculanida - Nuculanidae
Nuculana subibasjana pointed nut clam