Dos Bocas Formation

Last updated
Dos Bocas Formation
Stratigraphic range: Chattian
(Deseadan)
~26–24  Ma
O
S
D
C
P
T
J
K
Pg
N
Type Geological formation
Unit of Subibaja Group
Underlies Villingota Formation
Overlies Zapotal Formation
Lithology
Primary Sandstone
Location
Coordinates 1°48′S80°48′W / 1.8°S 80.8°W / -1.8; -80.8 Coordinates: 1°48′S80°48′W / 1.8°S 80.8°W / -1.8; -80.8
Approximate paleocoordinates 3°36′S75°30′W / 3.6°S 75.5°W / -3.6; -75.5
Region Santa Elena Province
CountryFlag of Ecuador.svg  Ecuador
Extent Progreso Basin
Equador physical map.svg
Orange ff8040 pog.svg
Dos Bocas Formation (Ecuador)

The Dos Bocas Formation is a Chattian, about 26 to 24 Ma, [1] (Deseadan in the SALMA classification) geologic formation of the Progreso Basin in southwestern Ecuador.

Contents

Description

The formation comprises moderately-sorted, fine to medium sandstones with angular quartz-feldspathic clasts. Conspicuous rounded green grains are probably glauconite, but berthierine cannot be dismissed. The matrix is micritic and volcanogenic, possibly bentonitic. The formation was deposited in an estuarine to mid shelf environment. Fossils of sharks, turtles and the tropical Urkudelphis were recovered from the formation. [1]

Fossil content

The formation has provided fossils of:

See also

Related Research Articles

Montañita Town in Santa Elena, Ecuador

Montañita is a small coastal town in Ecuador located in the parish of Manglaralto, province of Santa Elena, about 180 kilometers northwest of Guayaquil. Its name means "small mountain." In the mid 20th century it was known as a surfing beach, with only a few fishermen's huts, and one or two surfers tents in summer, erected at the site. But in 1960, Montañita, foreigners linked to the hippie movement decided to settle there permanently. It is now a popular destination for surfers from around the world and considered one of the best surfing beaches in Ecuador's south coast.

Santa Elena Province Province of Ecuador

The Province of Santa Elena is a province of Ecuador in the coastal region. Created in 2007 from territory that belonged to the Guayas Province, it is one of the two newest provinces of Ecuador, along with Santo Domingo de Los Tsáchilas. Its capital city is Santa Elena, from which the province derives its name.

The Magallanes Basin or Austral Basin is a major sedimentary basin in southern Patagonia. The basin covers a surface of about 170,000 to 200,000 square kilometres and has a NNW-SSE oriented shape. The basin is bounded to the west by the Andes mountains and is separated from the Malvinas Basin to the east by the Río Chico-Dungeness High. The basin evolved from being an extensional back-arc basin in the Mesozoic to being a compressional foreland basin in the Cenozoic. Rocks within the basin are Jurassic in age and include the Cerro Toro Formation. Three ages of the SALMA classification are defined in the basin; the Early Miocene Santacrucian from the Santa Cruz Formation and Friasian from the Río Frías Formation and the Pleistocene Ensenadan from the La Ensenada Formation.

Paraná Basin Large cratonic sedimentary basin situated in the central-eastern part of South America

The Paraná Basin is a large cratonic sedimentary basin situated in the central-eastern part of South America. About 75% of its areal distribution occurs in Brazil, from Mato Grosso to Rio Grande do Sul states. The remainder area is distributed in eastern Paraguay, northeastern Argentina and northern Uruguay. The shape of the depression is roughly elliptical and covers an area of about 1,500,000 km2 (580,000 sq mi).

The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene. These periods are referred to as ages, stages, or intervals and were established using geographic place names where fossil materials where obtained.

The Tinguirirican age is a period of geologic time within the Late Eocene and Early Oligocene epochs of the Paleogene, used more specifically within the SALMA classification in South America. It follows the Divisaderan and precedes the Deseadan age.

The Deseadan age is a period of geologic time within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tinguirirican and precedes the Colhuehuapian age.

The Colhuehuapian age is a period of geologic time within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian age.

The Santacrucian age is a period of geologic time within the Early Miocene epoch of the Neogene, used more specifically with SALMA classification in South America. It follows the Colhuehuapian and precedes the Friasian age.

Protocyon is an extinct genus of large canid endemic to South and North America during the Late Pleistocene living from 781 to 12 thousand years ago.

Malargüe Group

The Malargüe Group is a group of geologic formations of the Neuquén Basin of the Mendoza, Neuquén, Río Negro and La Pampa Provinces in northern Patagonia, Argentina. The formations of the Malargüe Group range in age between the middle Campanian to Deseadan, an Oligocene age of the SALMA classification, straddling the Cretaceous–Paleogene boundary, about 79 million to 30 million years in age. The group overlies the older Neuquén Group, separated by an unconformity dated to 79 Ma. The rocks of the Malargüe Group comprise both marine and continental deposits which are over 400 m (1312 ft) thick in total.

Chicamocha Canyon

The Chicamocha Canyon is a steep sided canyon carved by the Chicamocha River in Colombia. With a maximum depth of 2,000 metres (6,600 ft), an area of 108,000 hectares and a length of 227 kilometres (141 mi), the canyon is the second-largest worldwide. The canyon is situated in the departments of Boyacá and Santander, stretching from Soatá in the southeast to Girón and Betulia in the northwest.

The Amazing Race 6 is the sixth season of the Latin American version of the American reality show The Amazing Race. As in seasons prior, the show consisted of 11 teams of different nationalities competing, though for this season the Race took place entirely in Ecuador. The program was broadcast throughout Latin America on cable network Space, and in Ecuador on TC Televisión. The prize for the winning team was US$100,000, which was less than the prize given in previous seasons.

Ecuador Highway 15

Ecuador Highway 15 (E15) is the main coastal trunk highway of mainland Ecuador.

Urkudelphis is an extinct genus of cetacean. The type species, Urkudelphis chawpipacha, was described in 2017 based on fossils found in the Dos Bocas Formation of Ecuador. It was a type of river dolphin.

<i>Boreostemma</i> Extinct genus of mammals

Boreostemma is an extinct genus of glyptodonts from northern South America. Fossils assigned to the genus were first described as belonging to Asterostemma from southern South America, but have been placed in the new genus Boreostemma by Carlini et al. in 2008. The type species is B. pliocena. Fossils of Boreostemma have been found in the Honda Group of Colombia, in Peru and Venezuela.

The Ituzaingó Formation, in older literature also described as Entre Ríos or Entrerriana Formation, is an extensive geological formation of Late Miocene age in the Paraná Basin of the Corrientes, Santa Fe and Entre Ríos Provinces in Mesopotamia, northeastern Argentina. The formation comprises mudstones, cross-bedded sandstones and conglomerates deposited in a fluvio-deltaic environment and is renowned for the preservation of a rich fossil assemblage, including many mammals, birds, reptiles, fish, bivalves, foraminifera, ichnofossils and flora.

The Tablazo Formation is a Middle Pleistocene geologic formation of Santa Elena Province in western Ecuador. The claystones and sandstones were deposited in an estuarine environment.

The Seca Formation is a Late Eocene geologic formation of the Progreso Basin in southwestern Ecuador. The shales of the formation have provided fossils of the marine snake Pterosphenus sheppardi.

References

  1. 1 2 Montañita/Olón at Fossilworks.org
  2. Tanaka et al., 2017

Bibliography

Further reading