BackgroundNumerous basaltic cinder cones and lava flows occur in the panhandle of SE Alaska on both sides of Behm Canal, which divides Revillagigedo Island from the mainland. The lava flows, which are locally columnar-jointed, overlie glacial-fluvial sediments and granitic gneisses of the Coast Mountains and are located on the east and SE sides of Revillagigedo Island and at Rudyerd Bay across Behm Canal to the east. Most exposures are on SE Revillagigedo Island, but outcrops also occur on the mainland east of Behm Canal at the southern end of Punchbowl Cove at Rudyerd Bay. Undisturbed cinder cones and lava-flow surfaces at Painted Peak on SE Revillagigedo Island and elsewhere indicated that most of the activity was postglacial (Brew, in Wood and Kienle 1990). Pumice, lapilli, and ash deposits locally cover parts of glaciated ridge tops. Lava flows at the outlet of Lake Grace near Behm Canal on the eastern side of Revillagigedo Island were considered to be of late-Pleistocene or Holocene age (Wanek and Callahan 1971). Minor andesitic and trachyandesitic flows are also present.
Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8