- Usage in publication:
-
- Buttle diatomite [member]
- Modifications:
-
- Named
- Biostratigraphic dating
- Dominant lithology:
-
- Diatomite
- AAPG geologic province:
-
- California Coast Ranges province
Summary:
Named as Buttle diatomite [member] of Monterey formation. Type locality designated in Buttle Canyon, NE/4 sec.15 T24S R10E (35 deg 51'52"N, 120 deg 52'10"W) Bradley 7.5' quad, Monterey Co, CA, which is located on southwest limb of Hames Valley syncline. Has been mapped for about 10 mi. Consists of diatomite about 500 ft thick. Overlies "typical Monterey formation" cherts, shales, and thinner beds of diatomite. Grades upward into gray white sandstone which was mapped as Santa Margarita formation by some geologists and as Pancho Rico formation by Reed (1925); author favors Pancho Rico. Assigned to Delmontian Stage (late Miocene). List of fossils included.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Buttle Member*
- Modifications:
-
- Adopted
- Redescribed
- Areal extent
- Dominant lithology:
-
- Diatomite
- Porcellanite
- Chert
- Dolomite
- AAPG geologic province:
-
- California Coast Ranges province
Summary:
Buttle Diatomite Member of Monterey Shale of Mandra (1960) is adopted as Buttle Member because unit contains minor amounts of porcellanite, chert, and dolomitic carbonate rock as well as being richly diatomaceous in its type locality. Forms a fringe of outcrops along northeast edge of Monterey Shale in Tierra Redonda Mountain and Bradley 7.5-min quadrangles, Monterey and San Luis Obispo Counties, California. Age is late Miocene.
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 ([ ]).