- Usage in publication:
-
- Pyramid Peak limestone*
- Modifications:
-
- Named
- Dominant lithology:
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- Limestone
- AAPG geologic province:
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- Alaska Southeastern region
Summary:
Typical section: west side of Pyramid Peak (for which unit is named) and lower eastern flank of Black Cap Mountain at a point 1 mile north of northern shore of Tidal Inlet, Alaska. Mainly light-colored thin-bedded to moderately thick-bedded limestone, but upper part contains some argillaceous beds interspersed with limestone. Thickness has not been measured directly, but calculated to be about 2200 ft thick. Overlies Upper Silurian Tidal Formation and underlies Rendu Formation. Age considered Upper Silurian. [Text (p. k21) says age is not known closer than interval between Late Silurian and Middle Devonian. Rendu Formation is unfossiliferous but Black Cap Limestone which overlies Rendu has Middle Devonian fossils.]
Source: GNU records (USGS DDS-6; Menlo 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 ([ ]).