| The Wrangell Volcanic Field (WVF), Alaska consists of volcanoes that were active starting at ;The Skookum Creek Volcanic Complex (SCVC) is an extinct volcano in the WVF, dominated by Trend 2a with minor quantities of Trend 1 eruptive products. The volcano was active between 3.25 and 2.25 Ma and contains three main eruptive phases: Initiation, Teresa and Old Faithful. A fourth vent, the Pecos Vent, represents unique compositions within the SCVC. The SCVC evolved through time from Initiation Phase bimodal volcanism to predominantly intermediate volcanism in the Teresa and Old Faithful Phases and the Pecos Vent. The Teresa and Old Faithful Phases constructed large edifices with a basaltic andesite to andesite main cone and, later flank eruptions of andesite to rhyolite. A wide variety of high Ni potential parental compositions are present that are not simply related to the intermediate compositions. Important processes in the petrogenesis within the SCVC vary with time and include crystal fractionation, magma mixing and crustal contamination. |
