- Usage in publication:
-
- Estes Conglomerate*
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Midcontinent region
Summary:
Name Estes "System" changed to Estes Conglomerate. Type locality designated north of Bogus Jim Creek, secs 3 and 10, T2N, R5E, Lawrence Co, SD in the Midcontinent region. Mapped in the central and south-central part of the map area in Meade, Lawrence, and Pennington Cos. Unconformably overlies Benchmark Iron-formation (new) of Nemo Group (revised) of middle Precambrian age. Is older than an intrusive metagabbro of middle Precambrian age. Part of the former Estes "System" removed from Estes and renamed Roberts Draw Limestone. Consists of quartzite, coarse conglomerate, arkose, pebbly and non-pebbly mica schist, and minor iron-formation. Of middle Precambrian age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Estes Formation*
- Modifications:
-
- Age modified
- AAPG geologic province:
-
- Midcontinent region
Summary:
Mapped with other iron-formations (units Xc, Xcq, pl.1) of Early Proterozoic age. Unconformably overlies Early Proterozoic Blue Draw Metagabbro and Benchmark Iron-formation. Is of Early Proterozoic age, as it must be younger than 2.2 Ga. Also called Estes Quartzite. Geologic map.
Source: GNU records (USGS DDS-6; Denver 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 ([ ]).