Name applied to basaltic lavas of Ricardo formation which underlie borate-bearing Kramer lake beds (late Miocene age) of Ricardo formation in vicinity of Kramer, Kern Co, CA. Most conspicuous summit where lavas are exposed is double top of Saddleback Mountain. Is holocrystalline olivine basalt with texture that is almost diabasic. Forms sheets of massive, black-weathered lava separated by zones of reddened arkosic sedimentary deposits. Individual flows range up to 200 feet thick; total thickness is about 600 feet. Unconformably overlies quartz monzonite and Rosamond formation. Age of basalt shown on geologic map of Kramer borate district as Tertiary.

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

Saddleback basalt of Ricardo formation of Gale (1946) is adopted and reassigned to Tropico group (new) in Kramer borate district. Type locality designated in Saddleback Mountain, S/2 sec.9 T11N R7W, Boron 15' quad, 4 mi north of Boron, San Bernardino Co, CA. Crops out as scattered exposures in low hills northwestward for 6 mi and westward for 10 mi. At type overlies quartz monzonite; elsewhere overlies with slight unconformity lower part of Tropico group (referred to as Rosamond formation by Gale (1946). Unconformably underlies upper part of Tropico group or fanglomerate of probable Pleistocene(?) age. Is probably Pliocene(?) age.

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

"Saddleback Basalt now considered early Miocene(?) as suggested by probable conformable relation to overlying beds that contain early middle Miocene vertebrate remains at Boron pit, or possibly older Tertiary." p.78-79

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