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  • Usage in publication:
    • Jansen Creek Member*
  • Modifications:
    • Named
  • Dominant lithology:
    • Sandstone
    • Conglomerate
  • AAPG geologic province:
    • Olympic Mountains province
Publication:

Snavely, P.D., Jr., Niem, A.R., MacLeod, N.S., Pearl, J.E., and Rau, W.W., 1980, Makah Formation; a deep-marginal-basin sequence of late Eocene and Oligocene age in the northwestern Olympic Peninsula, Washington, IN Shorter contributions to stratigraphy: U.S. Geological Survey Professional Paper, 1162-B, 28 p. [Available online from the USGS PubsWarehouse: http://pubs.er.usgs.gov/pubs/pp/pp1162B]


Summary:

Named for exposures at mouth of Jansen Creek, SE/4 SE/4 sec.26 T33N R14W. Type section: sea cliffs, wave-cut platforms, and sea stacks from headland 0.5 km east of Bullman Creek to point 0.7 km southeast of Brush Point, NE/4 NW/4 sec.6 T32N R13W, Strait of Juan de Fuca, Clallam Co, WA. Is youngest member (of 6) of Makah Formation. Consists of basaltic sandstone and conglomerate. Forms deformed, thick-bedded, fossiliferous, cliff-forming, shallow-water olistostrome deposits. Is 200 m thick. Lies 250 m above Third Beach Member (new) (Makah Formation); overlies and underlies, with sharp contacts, unnamed undeformed deep-water marine strata of Makah Formation. Is early Oligocene age.

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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