An introduction to facies analysis in volcanic terrains

Abstract

Volcanic terrains consist of a greater variety of rock types than any other surface environment on Earth. They include lavas, deposits of explosive pyroclastic eruptions, primary volcanic autoclastic deposits and deposits resulting from the very significant spectrum of sedimentary processes that operate in volcanic terrains. Until the 1960s the amount of detailed and systematic work on the physical processes producing this diversity of rock types was subordinate to studies on the chemistry, mineralogy and petrogenesis of the volcanics. The growing need to understand better the processes operating and the peculiar depositional environments of volcanic terrains, in conjunction with major advances in the field of sedimentology, have led to a major growth in research and understanding of the physical processes.