Pitfalls in erosion level calculation based on remnants of maar and diatreme volcanoes

Abstract

Erosion estimates based on geometrical dimension measurements of eroded maar/diatreme volcanoes are useful methods to determine syn-volcanic surface level and syn-volcanic bedrock stratigraphy. However, such considerations on volcanic architecture should only be employed as a first-order approach to determine the state of erosion. We demonstrate, on both young and eroded maar/diatreme volcanoes, that establishing the volcanic facies architecture gives vital information on the environment in which the volcano erupted. In ‘soft’ rocks, maar volcanoes are broad and underlain by ‘champagne glass’-shaped diatremes. In contrast, the crater wall of maar volcanoes that erupted through ‘hard rocks’ will be steep, filled with lacustrine volcaniclastic deposits and underlain by deep diatremes.