Juana Diaz Formation, Puerto Rico geologic unit Tjd

Basal gravel to conglomerate overlain by limestone. Maximum estimated thickness is 850 m. Exposed in the Ponce, Rio Descalabrado, Penuelas, Punta Cuchara, Yauco, Punta Verraco, Guanica, and Sabana Grande quadrangles

Label	Tjd
Geologic age	middle Miocene-lower Oligocene
Quadrangles	Guánica, Peñuelas, Ponce, Punta Cucharas, Punta Verraco, Río Descalabrado, Sabana Grande, Yauco
Municipios	Guanica, Guayanilla, Juana Diaz, Lajas, Penuelas, Ponce, Santa Isabel, Yauco

Bibliographic references

Monroe, W.H., 1973, Geologic map of the Bayamon quadrangle, Puerto Rico: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-751, scale 1:20,000.Monroe, W.H., 1980, Geology of the Middle Tertiary formations of Puerto Rico: U.S. Geological Survey Professional Paper 953, Washington, D.C., 93 p.Monroe, W.H., 1980, Relief map of Puerto Rico showing principal physiographic provinces: U.S. Geological Survey Professional Paper 1159, scale 1:240,000.Monroe, W.H., 1980, Some tropical landforms of Puerto Rico: U.S. Geological Survey Professional Paper 1159, Washington D.C., 39 p.

Zapp, Bergquist, and Thomas, 1948

Bermudez and Seiglie, 1970

Glover and Mattson, 1973

Seiglie and Bermudez, 1969

Moussa and Seiglie, 1970

Krushensky and Monroe, 1975

Krushensky and Monroe, 1978