U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Tumac Mountain Olivine Basalt
  • Modifications:
    • Named
  • Dominant lithology:
    • Basalt
  • AAPG geologic province:
    • Cascades province
Publication:

Ellingson, J.A., 1972, The rocks and structure of the White Pass area, Washington: Northwest Science, v. 46, no. 1, p. 9-24.


Summary:

Named credited to A.T. Abbott (1953, unpub. PhD thesis). Lavas form Tumac Plateau along Cascade Crest between Carlton Pass and White Pass and form intracanyon flows in Summit and Indian Creeks, Yakima Co, WA. Geologic sketch map and structure section of White Pass Region show unit unconformably overlies Russell Ranch Formation, is in fault contact with pre-Tertiary Indian Creek Amphibolite (new) at Clear Lake fault zone, and is intruded by Jug Lake pluton. Age given as Quaternary.

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


Map showing publication footprint
  • Usage in publication:
    • Tumac Mountain Basalt
  • Modifications:
    • Age modified
  • AAPG geologic province:
    • Cascades province
Publication:

Hammond, P.E., Bentley, R.D., Brown, J.C., and Ellingson, J.A., 1977, Volcanic stratigraphy and structure of the southern Cascade Range, Washington; Field trip no. 4, IN Brown, E.H., and Ellis, R.C., eds., Geological excursions in the Pacific northwest: Geological Society of America [Guidebook for Field Trips], [90th] annual meeting, Seattle, WA, November 7-9, 1977, p. 127-169.


Summary:

Tumac Mountain Basalt of Ellingson (1972) described as gray, phyric, olivine basalt. Underlies glaciated plateau capped by postglacial Tumac Mountain cinder cone. Age given as 30,000(?) to 10,000(?) yr B.P.

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 ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Wed 12 Mar 2025 03:43:28 PM MDT