Esmeraldas Formation, Ecuador

The Esmeraldas Formation is an Early Pliocene (Montehermosan to Chapadmalalan in the SALMA classification) geologic formation of the Borbón Basin in northwestern Ecuador.[1]

Esmeraldas Formation
Stratigraphic range: Early Pliocene
(Montehermosan-Chapadmalalan)
~5.3–3.6 Ma
TypeGeological formation
OverliesBorbón Formation
Lithology
PrimaryMudstone
OtherSandstone, tuff
Location
Coordinates1.0°N 79.8°W / 1.0; -79.8
Approximate paleocoordinates0.8°N 79.0°W / 0.8; -79.0
RegionEsmeraldas & Manabí Provinces
Country Ecuador
ExtentBorbón Basin
Type section
Named forEsmeraldas
Esmeraldas Formation, Ecuador (Ecuador)

Description

The bioturbated, tuffaceous, green mudstones and sometimes sandstones with small or medium-sized rounded pebbles are scattered throughout the formation, or more rarely concentrated into minor beds or seams of conglomerate. Large calcareous concretions, some rounded or with an irregular rootlike shape, generally with hollow centers are common at many places. The beds are highly foraminiferal, with pelagic types, often pure enough to form a foraminiferal ooze-like sediment. On the fresh surface of the rock platform, the formation is hard, and of a gray-black or dark olive-green color. The sediments were deposited in a deep marine environment.[1]

Fossil content

The formation has provided bivalve, gastropod, echinoid, coral, bryozoa, radiolaria, foraminifera and scaphopod fossils.[1]

See also

References

Further reading

  • P. F. Hasson and A. G. Fischer. 1986. Observations on the Neogene of Northwestern Ecuador. Micropaleontology 32(1):32-42
  • P. Jung. 1989. Revision of the Strombina-group (Gastropoda; Columbellidae), fossil and living. Schweierische Paläontologische Abhandlungen 111:1-298
  • A. A. Olsson. 1964. Neogene Mollusks From Northwestern Ecuador
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.