- Usage in publication:
-
- Chisna formation*
- Modifications:
-
- Named
- Dominant lithology:
-
- Conglomerate
- Tuff
- Quartzite
- AAPG geologic province:
-
- Alaska Southern region
Summary:
Outcrops at head of Chisna River and in hills east and west of Chisna, central Copper River region, southern AK. Unit seems to form interrupted belt along southern base of Alaska Range from the Chisna west to the upper Delta. Consists of quartzitic conglomerate (75 ft thick), pyritiferous tuffs cut by porphyritic intrusives, and rusty quartzites. Tentatively assigned to Devonian or lower Carboniferous.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Chisna Formation*
- Modifications:
-
- Age modified
- AAPG geologic province:
-
- Alaska Southern region
Summary:
In Copper River basin, mapped undivided with Strelna Formation, Dadina Schist, and Klutina Group. Assigned age of Carboniferous and possibly older(?) for all four units.
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 ([ ]).