GEOLEX

Summary of Citation: Anon

Publication:
Mattson, P.H., 1967, Cretaceous and lower Tertiary stratigraphy
   in west-central Puerto Rico, IN Contributions to stratigraphy:
   U.S. Geological Survey Bulletin, 1254-B, p. B1-B35

Usage in Publication:
Anon Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Redescribed Revised	Caribbean region	Lava Pyroclastics

Summary:
Outside the type locality the Anon is of mixed lithologies, largely a complex of interbedded lava and pyroclastic rocks with only minor volcanic intrusive rocks and minor mudstone and volcanic sandstone, and analyses show that the rocks are dacite with minor andesite. For these reasons it is redefined here as Anon Formation. Gradationally overlies and interfingers with the Monserrate Formation; upper contact has been removed by erosion. Thickness is about 1,400 m. Age is middle to late Eocene in west-central PR based on Foraminifera.

Summary of Citation: Anon

Publication:
Krushensky, R.D. and Curet, A.F., 1977, Unconformity between
   the Late Cretaceous and early Tertiary in western Puerto
   Rico; concept rejected, IN Geological Survey research 1977:
   U.S. Geological Survey Professional Paper, 1050, p. 91

Usage in Publication:
Anon Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Caribbean region

Summary:
In the Monte Guilarte quadrangle the Anon is interbedded with the Yauco, Lago Garzas, and Maricao Formations of Late Cretaceous age. Anon in type area is Eocene, and partly Cretaceous.

Summary of Citation: Anon

Publication:
Krushensky, R.D. and Curet, A.F., 1984, Geologic map of the
   Monte Guilarte quadrangle, Puerto Rico: U.S. Geological Survey
   Miscellaneous Investigations Series Map, I-1556, 1 sheet,
   scale 1:20,000

Usage in Publication:
Anon Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Caribbean region

Summary:
Interbedded lithofacies of the Anon and Lago Garzas are not given separate formation names. Therefore the Santas Pascuas Member of the Lago Garzas is abandoned and considered to be a lithofacies of the Anon. The Mal Paso and Palma Escrita Formations are abandoned and are considered to be interbedded facies of the Anon and Lago Garzas. Different formational names have been applied to lithofacies of the Anon Formation in the Ponce, Jayuya, Adjuntas, Monte Guilarte, Bayaney, Maricao, and San Sebastian quads, but the rocks are lithologically identical to the Anon as defined by Mattson (1967) and are not distinguishable from similar repetitive sequences in the Anon proper. Along the border of the Adjuntas and Penuelas quads, the Robles (Maricao) is identical to the Anon (former Santas Pascuas Member of the Lago Garzas). Lithofacies characteristics of the Anon, Maricao, and Yauco are interbedded in the Monte Guilarte quad. Age is Late Cretaceous (Maestrichtian?) through Eocene.

Summary of Citation: Anon

Publication:
Krushensky, R.K., in press, Geologic map of Puerto Rico: U.S.
   Geological Survey Miscellaneous Investigations Series Map,
   I-__

Usage in Publication:
Anon Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Caribbean region

Summary:
The Anon Formation occurs in southwestern Puerto Rico and consists of volcanic breccia and lava, subordinate tuff, tuffaceous sandstone, siltstone, and mudstone. Maximum estimated thickness is 2000 meters. The Anon is of Late Cretaceous to Eocene age.