The Ponce Limestone is a
geologic formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
in
Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated ...
. It preserves
fossils dating back to the
Neogene period
Period may refer to:
Common uses
* Era, a length or span of time
* Full stop (or period), a punctuation mark
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (or rhetorical period), a concept ...
(20.45 million years ago (
Mya).
Description
Ponce Limestone includes beds of brown clay and has a maximum estimated thickness of 850 meters. It consists mostly of yellowish-orange, soft to moderately hard,
fossiliferous limestone
Fossiliferous limestone is any type of limestone, made mostly of calcium carbonate (CaCO3) in the form of the minerals calcite or aragonite, that contains an abundance of fossils or fossil traces. The fossils in these rocks may be of macroscopic ...
and appears almost continuously as a narrow band extending from Bahía Montalva in
Patillas to
Río Pastillo
Río Pastillo is a river in the municipality of Ponce, Puerto Rico. It is also known as Río Marueño in the area of the municipality where it runs through barrio Marueño. Together with Cañas River, Pastillo forms Matilde River. Pastillo ...
, in
Barrio Canas
Canas is one of the 31 barrios in the municipality of Ponce, Puerto Rico. Along with Anón, Coto Laurel, Guaraguao, Quebrada Limón, Real, San Patricio, and Marueño, and the coastal barrio of Capitanejo, Canas is one of the municipality's ni ...
.
Deposits
Exposed in the
Ponce,
Río Descalabrado,
Punta Cucharas
Reserva Natural Punta Cucharas (Punta Cucharas Nature Reserve) is a nature reserve in Barrio Canas, Ponce, Puerto Rico. It consists of both a land area component as well as an offshore marine area. The land component has an area of while the ...
,
Yauco
Yauco () is a town and municipality in southern Puerto Rico. Although the downtown is inland, the municipality stretches to a southern coast facing the Caribbean Sea. Yauco is located south of Maricao, Lares and Adjuntas; east of Sabana G ...
,
Punta Verraco,
Guanica,
La Parguera,
San German, and
Cabo Rojo quadrangles of the
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
maps.
Fossil content
Various fossils have been found in the Ponce Limestone: molds of gastropods, pelecypods, coral heads, and large foraminifera are indicative of deposition in shallow-water lagoon and back-reef environments. The large foraminifera, Lepidocyclina undosa and the ahermatypic “deep sea” coral Flabellum are reported within the Ponce Limestone.
''Geology and Hydrogeology of the Caribbean Islands Aquifer System of the Commonwealth of Puerto Rico and the U.S. Virgin Islands.''
Renken, Robert, et al. U.S. geological Survey. Professional Paper 1419. Reston, Virginia. 2002. p. 20. Accessed 14 November 2019.]
See also
* List of fossiliferous stratigraphic units in Puerto Rico
* Caliche
Caliche () is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semiarid regions ...
References
External links
''Geology and Hydrogeology of the Caribbean Islands Aquifer System of the Commonwealth of Puerto Rico and the U.S. Virgin Islands: Regional Aquifer-System Analysis.''
ROBERT A. RENKEN, W.C. WARD, I.P. GILL, FERNANDO GÓMEZ-GÓMEZ, JESÚS RODRÍGUEZ-MARTÍNEZ, et al. USGS. Professional Paper 1419. Reston, Virginia. 2002. Accessed 13 November 2019.
''Geologia del Distrito Ponce.''
G. J. Mitchell. Revista de Obras Publicas de Puerto Rico. Year VII. Issue 1. January 1930. Pages 7–9. Accessed 1 August 2020.
Further reading
* Monroe, W.H., 1972, Geology of the middle Tertiary rocks in the Ponce-Guanica area—a progress report: U.S. Geological Survey Open-File Report 72-258, Washington, D.C., scale 1:20,000.
''USGS Pub ofr72258.''
* Volckmann, R.P., 1984a, Geologic map of the Cabo Rojo and Parguera quadrangles, southwest Puerto Rico: U.S. Geological Survey Miscellaneous Investigations Series Map I-1557, scale 1:20,000.
''USGS Pub i1557.''
* Volckmann, R.P., 1984b, Geologic map of the Puerto Real quadrangle, southwest Puerto Rico: U.S. Geological Survey Miscellaneous Investigations Series Map I-1559, scale 1:20,000.
''USGS Pub i1559.''
* Krushensky and Monroe, 1975
* Krushensky and Monroe, 1978
* Krushensky and Monroe, 1979
* Mattson and Glover, 1973
* Monroe, W.H., 1973b
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Limestone formations
Neogene Puerto Rico
Geography of Ponce, Puerto Rico
Geologic formations of Puerto Rico
Geologic formations of the Caribbean