The basalt of Dodge in Eckler Mountain Member of Wanapum Basalt of Yakima basalt subgroup [informal] of Columbia River Basalt Group. Characterized by coarse grain size and moderately abundant large phenocrysts and glomerocrysts of plagioclase as much as 2 cm across. Smectitic alteration is common. Generally consists of one flow but locally comprises as many as four flows; maximum thickness about 40 m. Described as a grussy flow containing weathering spheroids whose cores are fresh; this is typical of Dodge flows at elevations below about 1,200 m (reference localities in Zumwalt, Rose Springs, Black Butte, and Saddle Butte quadrangles, Washington, and in Flora quadrangle, Oregon; see p. G29). At higher elevations, the basalt of Dodge tends to lose its grussy aspect and is more resistant to weathering. Can be confused with some plagioclase-phyric Frenchman Springs flows, but its grain size and average glomerocryst size are both greater than in most Frenchman Springs flows. Has normal magnetic polarity. Age is middle Miocene.
Named for a flow exposed in roadcut along Highway 127, in SW/4 NE/4 sec. 16, T. 12 N., R. 40 E., Hay quadrangle, 1.5 km by road from the intersection of Highways 127 and 12 at Dodge, Garfield County, Washington (see fig. 1, loc. 30).
[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).]

Source: Publication; US geologic names lexicon (USGS Bull. 1564, Eckler Mountain entry p. 53); Changes in stratigraphic nomenclature, 1979 (USGS Bull. 1502-A, p. A24).