- Usage in publication:
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- Atco chalk
- Modifications:
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- Areal extent
- Dominant lithology:
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- Chalk
- AAPG geologic province:
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- Ouachita folded belt
Summary:
Pg. 353. Atco chalk of Austin group. Basal formation of Austin group. According to Durham, 1957 (unpub. PhD dissert., Columbia Univ.) the type Austin sequence (in vicinity of Austin, Williamson County, Texas) includes (ascending) Atco chalk, Bruceville chalk-marl, Vinson chalk, Jonah limestone, Dessau chalk, Burditt chalk marl, and Big House chalk. Unconformably overlies Eagle Ford group. Is equivalent to lower chalk member in the Austin of the Dallas Geological Society in vicinity of Dallas, TX. Age is Late Cretaceous (Gulfian; Austinian).
[Typographical error (US geologic names lexicon, USGS Bull. 1350, p. 35): type Austin sequence is stated to be in Williamson Co., not Travis Co.]
Source: Publication; US geologic names lexicon (USGS Bull. 1350, p. 35); GNU records (USGS DDS-6; Denver 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 ([ ]).