(Angela’s Cone): Sample collected by M. Zimmer and A. Roach. Loosely coherent tephra from pyroclastic flow at Angela’s Cone, a newly-discovered, parasitic cinder cone on southern flank of Makushin volcano. Angela’s Cone is almost entirely dissected by ice, streams, and weathering, and shows no signs of recent activity. Groundmass is red-orange and extremely altered, with 1-3 mm dark clasts evenly distributed throughout (~30%). Phenocrysts of olivine and clinopyroxene, with 2 mm crystal clots. Olivines contain oxides, and lighter and darker green clinopyroxene populations were observed. Some olivines have an orange tint and are likely altered. Yielded olivine- hosted melt inclusions.
The role of water in generating the calc-alkaline trend: new volatile data for Aleutian magmas and a new tholeiitic index
This website is supported by the U.S. Geological Survey under Cooperative Agreement Grant G19AC00060 and G19AC00171.
Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.