Hyperacidic Volcanic Lakes, Metal Sinks and Magmatic Gas Expansion in Arc Volcanoes

Abstract

Hyperacidic volcanic lakes are expressions of much larger scale magmatic gas expansion inside volcanoes from source to surface. Their temperature and acidity are sustained by the capture of heat and SO2 (and HCl) and a suite of metals and metalloids, including Cu, Fe, As, Au, Bi, Se, Te, and Sb, from the magmatic gas. These lakes, together with high temperature fumaroles, therefore provide clues about the physics and chemistry of high temperature gas flow at the volcano scale that otherwise are inaccessible to direct observation. Understanding of the relationship between acidic volcanic lakes and these larger scale processes also has implications for modeling the flank stability of active volcanoes and how economically-valuable copper and gold deposits formed in ancient volcanoes. Such understanding may also translate to considerations of sulfur-rich environments on other planets as well as to the origin of life on earth.