Argillic alteration in the Novarupta vent region, Katmai National Park, Alaska
Keith TE. 1991. Argillic alteration in the Novarupta vent region, Katmai National Park, Alaska. Geophysical Research Letters. 18(8):1549-1552
Secondary mineralogy in the 1912 vent region at Novarupta illustrates an alteration history that evolved from high temperature degassing of ejecta through surficial argillic alteration to near neutral, wet steam alteration as the post eruptive volcanic system cooled. The locallized distribution of surficial argillizaiton appears to have been controlled mainly by fractures related to slumping and compaction in the near surface fall back ejecta. The fractures guiding the surviving warm, near neutral fumarolic fluids, however, must be connected with deeper vent structures that reach a subsurface heat source, perhaps the boiling zone of a hydrothermal system. Trace metals, including Mo, Pb, Cu, Cd, and Zn, concentrated by high temperature, vapor phase mobilizaiton, have subsequently been partly removed by argillization processess; in contrast, Hg, Sb, Tl, Bi, and As remain high even though the fumaroles now emit only low temperature near neutral wet steam.
- Type
- Journal Article
- Authors
- Keith, Terry
- Units
- KATM
- Keywords
- argillization, Geochemistry, Katmai National Park And Preserve, Metasomatism, Novarupta, Petrology, Processes, secondary minerals, Trace Elements, Vents