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Map showing publication footprint
  • Usage in publication:
    • Locatelli formation*
  • Modifications:
    • Named
    • Biostratigraphic dating
  • Dominant lithology:
    • Siltstone
    • Sandstone
  • AAPG geologic province:
    • California Coast Ranges province
Publication:

Cummings, J.C., Touring, R.M., and Brabb, E.E., 1962, Geology of the northern Santa Cruz Mountains, California, IN Bowen, O.E., ed., Geologic guide to the oil and gas fields of northern California: California Division of Mines and Geology Bulletin, no. 181, p. 179-220, (incl. geologic map, scale 1:51,200)


Summary:

Named [Brabb, 1960, PhD thesis] for exposures near Locatelli ranch. Type section designated along unnamed tributary of Scott Creek in S/2 sec.17 T9S R3W, north flank of Ben Lomond Mountain, Big Basin 7.5' quad, Santa Cruz Co, CA. Consists of dark gray, massive siltstone with few beds of interstratified sandstone. Is approximately 250 feet thick along Scott Creek and possibly as much as 800 feet in vicinity of Jamison Creek. Overlies quartz diorite; unconformably underlies Butano sandstone. Age is Paleocene (Ynezian Stage) based on microfossils.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Locatelli Formation*
  • Modifications:
    • Adopted
    • Overview
  • AAPG geologic province:
    • California Coast Ranges province
Publication:

Clark, J.C., 1981, Stratigraphy, paleontology, and geology of the central Santa Cruz Mountains, California Coast Ranges: U.S. Geological Survey Professional Paper, 1168, 51 p., (incl. geologic maps, scale 1:24,000)


Summary:

Locatelli Formation of Brabb (1960) and Cummings and others (1962) is adopted. Best exposures are in Smith Grade-Empire Grade area where unit extends over crest of Ben Lomond Mountain. Lists of mega- and microfossils included. Age is Paleocene (Ynezian Stage). Geologic map shows distribution.

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 ([ ]).

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