Marks (1951) IPC# 1080 (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 uppermost part of blue siltstone mbr, 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 61088: 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 - Turritellidae
"Turritella infracarinata" = Turritella (Turritella) infracarinata
"Turritella infracarinata" = Turritella (Turritella) infracarinata Grzybowski 1899 turret shell
 Neogastropoda - Muricidae
 Neogastropoda - Buccinidae
Hanetia sp., Phos haughti, "Cantharus predistortus" = Nicema predistorta
Hanetia sp. Jousseaume 1880 true whelk
Phos haughti Marks 1951 true whelk
"Cantharus predistortus" = Nicema predistorta Marks 1951 true whelk
 Neogastropoda - Columbellidae
"Strombina striatocostata" = Strombina (Strombina) colinensis
"Strombina striatocostata" = Strombina (Strombina) colinensis Hodson 1931 snail
 Neogastropoda - Clavatulidae
Turricula sp. Schumacher 1817 snail
 Heterostropha - Architectonicidae
Bivalvia
 Arcida - Arcidae