Studies of volcanic ash from two recent Central American eruptions
The 1971 eruptions of Cerro Negro volcano in Nicaragua and Fuego volcano in Guatemala produced ash blankets with minimum volumes of 7 × 107 m3 and 6 × 107 m3, respectively. Seven new chemical analyses show that ash produced by both eruptions was basaltic and similar to previously — erupted lavas of both volcanoes. Both ash blankets were sampled areally and stratigraphically before they were affected by rain. Chemical analyses of soluble materials leached from these ashes show that near the end of both eruptions the concentrations of soluble materials increased by about an order of magnitude. These changes are believed to reflect changes in the composition of eruptive gases.
Rose, William I.; Bonis, S.; Stoiber, R. E.; Keller, M.; and Bickford, T., "Studies of volcanic ash from two recent Central American eruptions" (1973). Department of Geological and Mining Engineering and Sciences Publications. 171.