- Usage in publication:
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- Asuncion group
- Modifications:
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- Original reference
- AAPG geologic province:
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- Coastal basins
Summary:
Pg. 2095. Upper Cretaceous sediments (Asuncion group) rest on lower Upper Cretaceous (Jack Creek formation) with angular unconformity up to 70 degrees, and overlap all older rocks. Asuncion group is thickest and most widespread of all divisions in Santa Lucia Range. Age is Late Cretaceous.
Source: US geologic names lexicon (USGS Bull. 1200, p. 158).
- Usage in publication:
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- Asuncion group
- Modifications:
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- Original reference
- Dominant lithology:
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- Conglomerate
- Sandstone
- Shale
- AAPG geologic province:
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- Coastal basins
Summary:
Pg. 132-134, pl. 2 [preprint 1941]. Name Asuncion group is used to include all of Upper Cretaceous beds in central Coast Ranges above Pacheco group (new). Asuncion group consists of over 10,000 feet of coarse conglomerates, sandstones and shales, which, in Santa Lucia Range, unconformably overlie Pacheco sediments and overlap onto all older rocks, Shasta, Knoxville, and Franciscan, and basement complex. In Santa Lucia Range, group is subdivided into Cantinas sandstones, Godfrey shales, and Piedras Altas formation (all new). On west side of San Joaquin Valley, group is divided into Panoche (restricted), Moreno, and Garzas formations. Majority of beds previously mapped in the region [central Coast Ranges] as "Chico" belong to Asuncion group. The two groups are separated by Santa Lucian orogeny.
Source: US geologic names lexicon (USGS Bull. 1200, p. 158).
- Usage in publication:
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- Asuncion group
- Asuncion formation
- Modifications:
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- Revised
- AAPG geologic province:
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- Coastal basins
Summary:
Pg. 484-512. Asuncion group and Asuncion formation. In this report, which discusses Cretaceous of Santa Lucia Range, both terms, Asuncion group and formation, are used. Asuncion group is separated from older Pacheco group by Santa Lucian orogeny. Asuncion formation unconformably overlies Jack Creek formation of Pacheco group. Ordinarily in fault contact with Lower Cretaceous Marmolejo formation (new), though in some areas there is angular discordance. Type section stated. Anderson's Upper Cretaceous Paskenta and Horsetown groups are considered faunal stages.
Type section: in Asuncion Grant, in southeast part of Adelaida quadrangle where there are good exposures of all phases along Santa Rita Creek, Templeton-Cayuocos Road, and road past Asuncion School, south-central CA
Source: US geologic names lexicon (USGS Bull. 1200, p. 158).
- Usage in publication:
-
- Asuncion group
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Coastal basins
Summary:
Pg. 30-71. Asuncion group. Discussion of subdivisions of Pacific Coast Upper Cretaceous. Taliaferro's terms Asuncion and Pacheco groups are used. All strata definitely referable to Senonian are included in Lower Asuncion group, and strata of probable Maestrichtian age are included in Upper Asuncion group.
Source: US geologic names lexicon (USGS Bull. 1200, p. 158).
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 ([ ]).