Signal Peak VulkanSignal Peak is the eroded remnant of a small andesitic stratovolcano overlying the southern part of the basaltic shield of the Lincoln Plateau.
Together with still active Mount Adams volcano to the west and the older Simcoe volcanic field of cinder cones to the east, it is part of a larger volcanic province that has been active for perhaps as much as 5 million years in the area.
Geologic Map of the Mount Adams Quadrangle, Washington. Compiled by M.A.Korosec, Washington Division of Geology and Earth Resources Open File Report 87-5 (1987)
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