- Usage in publication:
-
- Eetza formation*
- Modifications:
-
- Named
- Dominant lithology:
-
- Gravel
- Clay
- AAPG geologic province:
-
- Great Basin province
Summary:
Named for Eetza Mountain as oldest (of 4) formations in Lahontan Valley group (new). Type locality designated as upper part of central gulch in Eetza Mountain, Churchill Co, NV. Exposed only in highlands above 3,950 ft elevation. Consists of lacustrine gravel to clay and tufa as much as 90 ft thick. Locally divisible into two tongues separated by tongue of alluvium and colluvium of Eetza age which bears a very weak soil. Lower tongue extends as high as highest Lake Lahontan shoreline, 4380 ft elevation; upper tongue reaches about 4340 ft elevation; intervening tongue is as low as 4065 ft elevation. Overlies pre-Lake Lahontan soil which in turn overlies Paiute formation (new); conformably underlies Wyemaha formation (new) (of Lahontan Valley group). Age given as late Pleistocene.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Eetza formation*
- Modifications:
-
- Adopted
- AAPG geologic province:
-
- Great Basin province
Summary:
Type locality designated as uppermost one-eighth mi of large southward-draining gulch in western part of Eetza Mountain, SW/4 sec.21 T18N R30E, Carson Desert [Carson Lake 15' quad, Churchill Co, NV]. At type overlies Bunejug formation (new); underlies Wyemaha formation or Sehoo formation (both of Lahontan Valley group). Upper and lower boundaries are sharp and readily identifiable. Overlies Cocoon soil. Shown on geologic maps of Fallon and Carson Lake 15' quads. Age given as Pleistocene.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
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- Eetza Alloformation
- Modifications:
-
- Principal reference
- Redescribed
- AAPG geologic province:
-
- Great Basin province
Summary:
Eetza Formation of Morrison (1961) redescribed as Eetza Alloformation as defined in 1983 North American Stratigraphic Code. Principal reference locality designated as exposures in Wadsworth Amphitheatre, E/2 sec.15 T21N R24E, Wadsworth 15' quad, Washoe Co, NV.
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 ([ ]).