Ponce Limestone Explained

Ponce Limestone
Type:	Formation
Age:	Neogene ~
Period:	Neogene
Prilithology:	Limestone
Otherlithology:	Carbonate,^[1] Clastic facies,^[2] Chalk, Marl, Shale Phosphate
Namedfor:	Ponce, Puerto Rico
Namedby:	Watson H. Monroe
Region:	Caribbean
Country:	Puerto Rico
Coordinates:	18.007°N -66.661°W
Paleocoordinates:	18°N -66.6°W

The Ponce Limestone is a geologic formation in Puerto Rico. It preserves fossils dating back to the Neogene period^[3] (20.45 million years ago (Mya).

Description

Ponce Limestone includes beds of brown clay and has a maximum estimated thickness of 850 meters.^[4] It consists mostly of yellowish-orange, soft to moderately hard, fossiliferous limestone and appears almost continuously as a narrow band extending from Bahía Montalva in Patillas to Río Pastillo, in Barrio Canas.^[5]

Deposits

Exposed in the Ponce, Río Descalabrado, Punta Cucharas, Yauco, Punta Verraco, Guanica, La Parguera, San German, and Cabo Rojo quadrangles of the United States Geological Survey maps.^[6]

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.^[7]

See also

• List of fossiliferous stratigraphic units in Puerto Rico
• Caliche

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

Notes and References

1. https://pubs.usgs.gov/pp/pp1419/pdf/BOOK.PDF 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.
2. https://pubs.usgs.gov/pp/pp1419/pdf/BOOK.PDF Geology and Hydrogeology of the Caribbean Islands Aquifer System of the Commonwealth of Puerto Rico and the U.S. Virgin Islands.
3. http://www.fossilworks.org/cgi-bin/bridge.pl?action=home Fossilworks: Gateway to the Paleobiology Database.
4. http://mrdata.usgs.gov/geology/pr/prgeo-unit.php?unit=Tpo Ponce Limestone.
5. https://pubs.usgs.gov/pp/pp1419/pdf/BOOK.PDF Geology and Hydrogeology of the Caribbean Islands Aquifer System of the Commonwealth of Puerto Rico and the U.S. Virgin Islands.
6. http://mrdata.usgs.gov/geology/pr/prgeo-unit.php?unit=Tpo Ponce Limestone.
7. https://pubs.usgs.gov/pp/pp1419/pdf/BOOK.PDF Geology and Hydrogeology of the Caribbean Islands Aquifer System of the Commonwealth of Puerto Rico and the U.S. Virgin Islands.