- Usage in publication:
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- Marble Bluff Bed
- Modifications:
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- Named
- AAPG geologic province:
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- Great Basin province
Summary:
Marble Bluff Bed. Attributed to Mount St. Helens in southwestern Washington because it contains cummingtonite, which is characteristic of Mount St. Helens tephra. Occurs in the Carson Desert and around Pyramid Lake in the Lake Lahontan area, Nevada. Is a graded bed, gray at the base and white at the top, 1 cm thick, and is the lowest tephra layer contained within the lower member of the Sehoo Formation. Underlies the Carson Sink Bed (new) of the Mono Basin Formation (new) and the Pelican Island Bed (new) and Wono Bed (new) of the Pyramid Lake Member (new) of the Mount Mazama Formation. Age is Pleistocene, 35 to 11.5 ka.
Type section: Marble Bluff, in banks of Mud Lake (Winnemucca) Slough, 5.6 km north of Nixon, in NW/4 NW/4 sec. 12, T. 23 N., R. 23 E., Nixon 15-min quadrangle, Washoe Co., NV.
Source: US geologic names lexicon (USGS Bull. 1565, p. 191).
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 ([ ]).