- Usage in publication:
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- Trout Creek sandstone member*
- Modifications:
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- Named
- Dominant lithology:
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- Sandstone
- AAPG geologic province:
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- Green River basin
- Piceance basin
Summary:
Name applied to a prominent ledge-forming sandstone about 1,900 ft above the base of the Mesaverde formation. Named for exposure near Trout Creek on the northeast side of Twentymile Park, Routt Co, CO in the Greater Green River basin and adjoining Rio Blanco Co, CO in the Piceance basin. No type locality designated. The sandstone is white, ridge- or ledge-maker, and friable. Is marked by cracks. Has large concretions. Overlies and underlies unnamed parts of the Mesaverde. Geologic map. Members of Mesaverde not individually mapped. Cretaceous age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Trout Creek sandstone member*
- Modifications:
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- Revised
- AAPG geologic province:
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- Green River basin
Summary:
Reassigned from member of Mesaverde formation to upper member of Iles formation of Mesaverde group. Is a 75 ft thick white sandstone in a section measured on east side of Milk Creek at opening into south side of Axial Basin, Moffat Co, CO in the Greater Green River basin. Of Cretaceous age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
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- Trout Creek Sandstone Member*
- Modifications:
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- Overview
- AAPG geologic province:
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- Green River basin
Summary:
Correlation of Upper Cretaceous Pierre Shale (and its Hygiene, Terry, Rocky Ridge, and Larimer Sandstone Members) near Boulder, CO with Pierre Shale (and its Sharon Springs, Kremmling, Muddy Buttes, Hygiene, Carter and Gunsight Pass Members) near Kremmling, CO, and with upper part of Mancos Shale (and its Morapos and Loyd Sandstone Members) and with Iles Formation (and its Tow Creek and Trout Creek Sandstone Members) and Williams Fork Formation (and its Twentymile Sandstone Member); the last two are formations of Mesaverde Group of Hamilton area, Moffat Co in Greater Green River basin shown on fig. 2.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Trout Creek Sandstone Member*
- Modifications:
-
- Areal extent
- Overview
- AAPG geologic province:
-
- Green River basin
- Piceance basin
Summary:
Mapped as uppermost member of Iles Formation in north-central part of quad. Trout Creek extends south just across Moffat-Rio Blanco Co border, Greater Green River and Piceance basins which is southern limit of Trout Creek. Described as light-gray to light-brown, massive to cross-bedded, fine- to medium-grained sandstone. Where absent, Williams Fork-Iles contact is placed at base of lowest coal bed of basal Williams Fork coal-bearing carbonaceous zone (which is probably slightly lower stratigraphically than Trout Creek). Maximum thickness is about 110 ft near north edge of quad. Conformably overlies main body of Iles; conformably underlies Williams Fork Formation. Late Cretaceous age. [Where Trout Creek is present, Iles and Williams Fork can be differentiated. Where Trout Creek is absent, Mesaverde Group is divided into (ascending): lower unit of Mesaverde Group, coal unit of Mesaverde Group, and upper unit of Mesaverde Group.]
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 ([ ]).