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Map showing publication footprint
  • Usage in publication:
    • Round Mountain Member
  • Modifications:
    • Overview
  • Dominant lithology:
    • Shale
    • Sandstone
  • AAPG geologic province:
    • Sacramento basin
Publication:

Manson, M.W., 1990, Landslide and flood potential along Cache Creek; Lake, Colusa, and Yolo Counties, California: California Geology, v. 43, no. 5, p. 99-106.


Summary:

Named by J.E. Lawton (1956, PhD thesis, Dissertation Abstracts, v.16 no.10 p.1885) for rocks in Morgan-Wilbur area in Lake, Yolo, and Colusa Cos, CA, as upper member of Little Valley Formation. Is predominantly light-gray to brown shale and silty shale, with minor mudstone, interbedded sandstone and some limestone. Is more than 4200 ft thick. Conformably overlies Leesville Member of Little Valley Formation. Conformably underlies Baldy Mountain Member of Davis Canyon Formation of Lawton (1956). Age given as Early Cretaceous.

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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