Calderas - A planetary perspective

It is pointed out that volcanoes are morphological expressions of magma composition, eruption processes, and regional tectonics. Thus, the lack of unambiguous silicic volcanoes and pyroclastic flows on Mars implies that compared to earth, its crust is deficient in volatiles and/or the planet lacks a thick granitic crust. Such deductions are examples of comparative planetology, in which knowledge of landforms and processes on one planet are utilized to interpret features and histories on others. In the present study calderas are considered in a comparative planetology context to provide perspective for students who investigate only terrestrial calderas and to search for broadscale relationships between calderas and planetary characteristics. Attention is given to terrestrial calderas, lunar calderas, Martian calderas, calderas on Jupiter's satellite Io, and calderas on Venus. A planetary definition of calderas is proposed.