The Riochican ( es, Riochiquense) age is a period of
geologic time
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geoc ...
(57.0–54.0
Ma) within the
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...
and
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...
epochs of the
Paleogene
The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (Mya) to the beginning of ...
, used more specifically within the
South American land mammal age
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 (0.011 Ma). These periods are referred to as age ...
s (SALMA). It follows the
Peligran and precedes the
Itaboraian age.
Paleo Database: Riochican
/ref>
Etymology
This age is named after the Río Chico Group
Rio or Río is the Portuguese, Spanish, Italian, and Maltese word for " river". When spoken on its own, the word often means Rio de Janeiro, a major city in Brazil.
Rio or Río may also refer to:
Geography Brazil
* Rio de Janeiro
* Rio do Sul, ...
of the Golfo San Jorge Basin
The Golfo San Jorge Basin ( es, Cuenca del Golfo San Jorge) is a hydrocarbon-rich sedimentary basin located in eastern Patagonia, Argentina. The basin covers the entire San Jorge Gulf and an inland area west of it, having one half located in Sant ...
.
Formations
Fossils
References
Bibliography
;Bogotá Formation
*
*
*
;Bororó Formation
*
;Chota Formation
*
*
;Las Flores Formation
*
;Koluel Kaike Formation
*
;Maíz Gordo Formation
*
;Mealla Formation
*
;Mogollón Formation
*
*
;Muñani Formation
*
;Peñas Coloradas Formation
*
*
;Río Loro Formation
*
;Salamanca Formation
*
*
*
*
*
{{SALMA
Paleocene South America
Eocene South America
Paleogene Argentina