Amazonian The youngest of the geologic epochs on Mars identified through geoiogic mapping of superposition relations, and the area! density of impact craters. caldera An irregular collapse feature formed over the evacuated magma chamber within a volcano. central volcano Emplacement of volcanic materials from a centralized source vent rather than along a distributed line of vents, composite volc...

a r t i c l e i n f o An evaluation of the historical record of volcanic eruptions shows that subaerial volcanism increases globally by two to six times above background levels between 12 ka and 7 ka, during the last deglaciation. Increased volcanism occurs in deglaciating regions. Causal mechanisms could include an increase in magma production owing to the mantle decompression caused by ablati...

*Correspondence: Eric Font, IDL-FCUL, Instituto Dom Luís, Faculdade de Ciências, Universidade de Lisboa, Edifício C8-8.3.22, Campo Grande, 1749-016 Lisboa, Portugal e-mail: [email protected] The environmental impact of the Deccan trap volcanism is poorly understood as yet. The paucity of geological markers that can unambiguously be attributed to the Deccan volcanism and the temporal coincid...

The Permian-Triassic boundary records the most severe mass extinctions in Earth's history. Siberian flood volcanism, the most profuse known such subaerial event, produced 2 million to 3 million cubic kilometers of volcanic ejecta in approximately 1 million years or less. Analysis of (40)Ar/(39)Ar data from two tuffs in southern China yielded a date of 250.0 +/- 0.2 million years ago for the Per...

There has clearly been significant volcanic activity on the surface of Venus in recent geological epochs and there is a great deal of indirect evidence that this may continue at the present time. However, the current level of activity is unknown and remains controversial, with estimates for the rate of emission of volcanic gases into the atmosphere ranging from essentially quiescent to very hig...

Subduction zones form dominant tectonic features on the Earth and are the site of large underthrusting earthquakes and explosive arc volcanism. They are also the only locations with deep earthquakes in the Earth’s interior. Major questions remain regarding the dynamics of subduction zones, including aspects such as the role of water in the formation of arc volcanism and deep earthquakes, the in...

differentiation The process by which planets and satellites develop layers or zones of different chemical and mineralogical composition. flyby Term used to describe the close approach of a spacecraft to a body, without the spacecraft going into orbit around that body. Galilean satellites The four largest satellites of Jupiter (Io, Europa, Ganymede, Callisto), named after their discoverer Galile...