- Usage in publication:
-
- Mal Paso Formation*
- Modifications:
-
- Named
- Dominant lithology:
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- Basalt
- Lava
- Limestone
Summary:
Mal Paso Formation, here named, consists of grayish-red-purple amygdaloidal basalt lava with amygdule fillings of white calcite and zeolites. Lavas are pillowed and contain olivine pseudomorphs. Foraminiferal limestone is interbedded with the pillow lavas. Conformably overlies Concepcion Formation; conformably underlies Rio Culebrinas Formation. Age is early middle Eocene based on Foraminifera.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Mal Paso†
- Modifications:
-
- Abandoned
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.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).