- Usage in publication:
-
- Trump formation
- Modifications:
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- Named
- Dominant lithology:
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- Gravel
- AAPG geologic province:
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- South Park basin
Summary:
Named for settlement of Trump, Park Co, CO, South Park basin. No type locality designated. Is widespread along south end of Park and along divide separating western head of Agate Creek from Badger Creek. No section measured but thickness estimated at 500 ft. Consists of gravel, usually poorly cemented. Pebbles in gravel represent practically all the older rocks of the region--such as pre-Cambrian crystalline rocks, Tertiary lavas, andesite, etc. Pebbles are fine and well rounded. Matrix is pure quartz sand with biotite flakes as a common accessory. Cement is silica; some is calcium carbonate. Stratification is poor. Locally cross bedding pronounced. Probably derived from several sources. No fossils found. Unconformably above Wagontongue formation, though relationship of two formations uncertain. Regarded as Pliocene age, and younger than Wagontongue. Geologic map.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Trump Conglomerate†
- Modifications:
-
- Abandoned
Summary:
Is now known to be a coarse facies of the Miocene Wagon-tongue Formation. Is an unnecessary name that was thought to be of Pliocene age formerly used in the South Park basin that is abandoned.
Source: 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 ([ ]).