- Usage in publication:
-
- Lignite Creek Formation*
- Modifications:
-
- Named
- Biostratigraphic dating
- Dominant lithology:
-
- Sandstone
- Claystone
- Coal
- AAPG geologic province:
-
- Alaska East-Central region
- Alaska Southern region
Summary:
Type section designated along Suntrana Creek from top of No.6 coal bed northward for 1000 ft to top of sandstone outcrop between 1st forks of creek, sec.23 T12S R7W, Healy D-4 quad, east-central AK. Has coal-bearing facies in Healy Creek, Lignite Creek, Tatlanika Creek (southern part) and Wood River coal basins. Noncoal-bearing facies is in northern and western parts of Nenana coal field which was mapped as Nenana Gravel by Capps (1940). Consists of repeated sequences of pebbly sandstone, claystone, and coal. Coal-bearing facies ranges from 500 to 800 ft thick. Non-bearing facies is as much as 1300 ft thick along north edge of foothills. Conformably overlies Suntrana Formation (new); conformably underlies Grubstake Formation (new) or Nenana Gravel. Is probably middle Miocene age on basis of fossil flora.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Lignite Creek Formation*
- Modifications:
-
- Revised
- Age modified
- AAPG geologic province:
-
- Alaska East-Central region
- Alaska Southern region
Summary:
Lignite Creek Formation is assigned as next to youngest formation (of 5) to Usibelli Group (new). Age is modified from middle Miocene to: late middle to early late Miocene Homerian Stage (Wolfe and Tanai, 1980).
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 ([ ]).