Geologic Unit: Winter Water

Usage:

Winter Water Member of Grande Ronde Basalt of Columbia River Basalt Group (OR*,WA*)
Winter Water Member of Grande Ronde Basalt of /Yakima basalt subgroup [informal] of Columbia River Basalt Group (OR*,WA*)

[Yakima basalt subgroup considered informal and should not be capitalized. "Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Columbia River Basalt Group adopted by the ID, OR, and WA Geol. Surveys, and the USGS (rules suspended).]

Geologic age:

late Tertiary (middle Miocene)*

Type section, locality, area and/or origin of name:

Reference localities: (1) Winter Water Creek, a tributary to Deschutes River, along OR State Route 216, [in NE/4 sec. 4, T. 4 S., R. 14 E., Sherars Bridge 7.5-min quadrangle, Wasco Co.], northern OR; (2) Rock Creek Canyon on OR State Route 206, in secs. 25, 35, and 36, T. 3 S., R. 22 E., Devils Gap 7.5-min quadrangle, [Gilliam Co., northern OR]; (3) Umatanum Ridge above Priest Rapids dam, in sec. 12, T. 13 N., R. 23 E., Priest Rapids 7.5-min quadrangle, [Yakima Co., southwestern WA]; and (4) [southeast of Schwana], Saddle Mountains, in sec. 2, [T. 15 N.], R. 23 E., Beverly 7.5-min quadrangle, [Grant Co., south-central WA] (Reidel and others, 1989; Reidel and Tolan, 2013, GSA Spec. Paper 497).

AAPG geologic province:

Eastern Columbia basin*