- Usage in publication:
-
- Kugruk group*
- Modifications:
-
- Named
- Dominant lithology:
-
- Limestone
- Schist
- Greenstone
- AAPG geologic province:
-
- Seward Peninsula province
- Alaska West-Central region
Summary:
Named as upper part of Nome series [probably for Kugruk Mountain or Kugruk River], northwestern part of Seward Peninsula, AK, where unit is shown on geologic map. Covers large area extending eastward from American River. Consists of interstratified limestones, mica-schists, and graphitic schists with intrusive masses of schistose greenstone. Conformably overlies Port Clarence limestone (new) of Nome series. Imperfect fossils found at Summit of Baldy Mountain are Late Silurian or Devonian age according to Charles Schuchert.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- "Kugruk group"†
- Modifications:
-
- Abandoned
- AAPG geologic province:
-
- Seward Peninsula province
- Alaska West-Central region
Summary:
Limestones of "Kugruk or Kougarok group" correlated with Port Clarence limestone. Upper part now referred to as undifferentiated schists of Nome group. [River from which Kugruk group derived its name has been changed to Kougarok River because there is another Kugruk River on Seward Peninsula].
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 ([ ]).