- Usage in publication:
-
- Schulz member
- Modifications:
-
- First used
- Dominant lithology:
-
- Sandstone
- Conglomerate
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Pg. 380. Schulz member of Williams formation (new). Briefly described in "Generalized section of formations in the Santa Ana Mountains, California." Is lower member (of 2) of Williams formation. Consists of light-colored coarse arkosic sandstones with numerous beds of well-rounded boulders; unfossiliferous. Average thickness 200 feet. Unconformably overlies Ladd formation (new); underlies Pleasants member (new) of Williams formation. A single fossil collection obtained from its lower part; this may represent reworked material from Holz shale member of Ladd formation below. Age is Late Cretaceous based on stratigraphic position.
Source: Publication; GNU records (USGS DDS-6; Menlo GNULEX); US geologic names lexicon (USGS Bull. 1200, p. 3500).
- Usage in publication:
-
- Schulz member
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Sandstone
- Conglomerate
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Pg. 166, 168 (fig. 2), 173-174. Schulz member of Williams formation (new). Is lower member (of 2) of Williams formation. Type locality designated. Consists of coarse, light-colored soft, cross-bedded, arkosic sandstone with subordinate boulder beds. Thickness about 200 feet in southern part of area mapped [northern Santa Ana Mountains, Orange County, California] but is thicker in region north of Baker Canyon. Disconformably overlies Ladd formation; underlies Pleasants member of Williams formation. Report includes columnar sections.
Type locality: approximately 0.25 mi upstream from mouth of Williams Canyon near west boundary of Schulz Ranch, northern Santa Ana Mountains, Orange Co., CA.
Source: US geologic names lexicon (USGS Bull. 1200, p. 3500); supplemental information from GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Schulz Ranch sandstone member*
- Modifications:
-
- Adopted
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Schulz member of Popenoe (1942) is adopted as Schulz Ranch sandstone member (lower member of 2 of Williams formation). Conglomerate of Schulz Ranch sandstone member directly underlies basal conglomerate of Silverado formation (new). Conglomerate of Silverado includes slate slabs and chips and subangular cobbles whereas conglomerate of Late Cretaceous age of Schulz Ranch is made up of rounded large cobbles and boulders.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Schulz Ranch Member
- Modifications:
-
- Redescribed
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Redescribed as Schulz Ranch Member in legend of geologic map of Orange Co, CA. Overlies Starr Member (new) and underlies Pleasants Sandstone Member (both of Williams Formation).
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 ([ ]).