Jarvis 1630000 yBP
Start: 1630000 yBP ± 420000 Years [1]
Event Type: Effusive
Description: From Richter and Smith (1976): "Dacite andesite and dacite flows. Thick sequence of thin to medium flows with minor interbedded tuffs and breccias representing main cone-building stage of Jarvis volcanoes which extend into the McCarthy D-7 and Nabesna A-6 quadrangles. Rocks are dark gray, and pinkish gray. Chiefly two-pyroxene dacitic andesite containing hypersthene, augite, plagioclase, and rare olivine phenocrysts in a felty plagioclase-rich matric. In southwest corner of quadrangle sequence is cut by numerous dark-colored dikes probably chiefly of andesite composition. K-Ar date (M.A. Lanphere, written commun., 1974) on plagioclase indicates age of 1.63+/-0.42 m.y. (Sample 72-ARh-307a)."
References Cited
[1] Geologic map of the Nabesna A-5 quadrangle, Alaska, 1976
Richter, D.H., and Smith, R.L., 1976, Geologic map of the Nabesna A-5 quadrangle, Alaska: US Geological Survey Geologic Quadrangle Map 1292, 1 sheet, available at http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=13027 .[2] Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska, 1994
Miller, T. P., and Richter, D. H., 1994, Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska: in Plafker, George, Jones, D. L., and Berg, H. C., (eds.), The Geology of Alaska, Geological Society of America The Geology of North America series v. G-1, p. 759-779.[3] Age and progression of volcanism, Wrangell volcanic field, Alaska, 1990
Richter, D. H., Smith, J. G., Lanphere, M. A., Dalrymple, G. B., Reed, B. L., and Shew, N., 1990, Age and progression of volcanism, Wrangell volcanic field, Alaska: Bulletin of Volcanology, v. 53, n. 1, p. 29-44.Complete Eruption References
Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve, 1995
Richter, D. H., Rosenkrans, D. S., and Steigerwald, M. J., 1995, Guide to the volcanoes of the western Wrangell Mountains, Alaska - Wrangell-St. Elias National Park and Preserve: U.S. Geological Survey Bulletin 2072, 31 p.
Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska, 1994
Miller, T. P., and Richter, D. H., 1994, Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska: in Plafker, George, Jones, D. L., and Berg, H. C., (eds.), The Geology of Alaska, Geological Society of America The Geology of North America series v. G-1, p. 759-779.
Hard Copy held by AVO at FBKS - CEC file cabinet
Age and progression of volcanism, Wrangell volcanic field, Alaska, 1990
Richter, D. H., Smith, J. G., Lanphere, M. A., Dalrymple, G. B., Reed, B. L., and Shew, N., 1990, Age and progression of volcanism, Wrangell volcanic field, Alaska: Bulletin of Volcanology, v. 53, n. 1, p. 29-44.
Geologic map of the Nabesna A-5 quadrangle, Alaska, 1976
Richter, D.H., and Smith, R.L., 1976, Geologic map of the Nabesna A-5 quadrangle, Alaska: US Geological Survey Geologic Quadrangle Map 1292, 1 sheet, available at http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=13027 .