The nature and origin of the small-scale volcanic systems, generally referred to as 'monogenetic', have enjoyed an elevated level of interest during the past decade. There has been recognition that their ostensibly simple volcano types are a window into the nature of explosive volcanism, landscape evolution and the processes of magma generation in the Earth’s upper mantle. In the past few years, major conferences have offered specialized technical sessions dealing with monogenetic volcanism and there have been thematic conferences, such as the IAVCEI International Maar Conference series, which have provided a focus for discussion of volcanological and geochemical aspects of small-scale basaltic volcanism. Many new aspects of monogenetic volcanism have emerged and have clearly demonstrated that this volcanism can be very complex on a fine scale. This book is a collection of papers arising from two recent Maar Conferences (the fifth in Queretaro Mexico and the sixth in Changchun, China) and serves as a snapshot of current research on monogenetic volcanism.

This memoir is the first to review all of Antarctica’s volcanism between 200 million years ago and the Present. The region is still volcanically active. The volume is an amalgamation of in-depth syntheses, which are presented within distinctly different tectonic settings. Each is described in terms of (1) the volcanology and eruptive palaeoenvironments; (2) petrology and origin of magma; and (3) active volcanism, including tephrochronology. Important volcanic episodes include: astonishingly voluminous mafic and felsic volcanic deposits associated with the Jurassic break-up of Gondwana; the construction and progressive demise of a major Jurassic to Present continental arc, including back-arc alkaline basalts and volcanism in a young ensialic marginal basin; Miocene to Pleistocene mafic volcanism associated with post-subduction slab-window formation; numerous Neogene alkaline volcanoes, including the massive Erebus volcano and its persistent phonolitic lava lake, that are widely distributed within and adjacent to one of the world’s major zones of lithospheric extension (the West Antarctic Rift System); and very young ultrapotassic volcanism erupted subglacially and forming a world-wide type example (Gaussberg).

Increasing evidence supports the claim that stress changes play a fundamental role in triggering volcanic eruptions. Stress changes may vary in origin to include earthquakes, erosion and landslide processes, deglaciation, or tidal effects. The local stress can also change as response of magma influx from deeper reservoirs and an increase of the magma/gas pressure. The stress transfer may be of great importance in reawakening a dormant system. As an example, significant statistical correlation of large earthquakes and eruptions in time and space was suggested in many works. The interaction may be two-fold; where magma intrusions may change the stress at active faults and trigger earthquakes, while tectonic earthquakes may affect the magmatic system and change the eruption activity. The change in local tectonic stress has been claimed as trigger of large ignimbrite eruptions or for controlling the eruptive style of explosive eruptions. Sometimes volcano systems that are nested or closely located may become active in chorus; neighbouring volcanoes may interact in the sense that one volcano triggers its neighbouring volcano. However, although there is ample evidence of concurrence, the processes of interacting volcanoes and near- to far-field tectonic stress are not well understood. Some studies suggest that volcanic eruptions are triggered if compressive stress acts at the magma system and “squeezes” out magma. Other studies suggest that extensional stress fields facilitate magma rise and thus encourage eruptions, or that fluctuating compression and extension during the passing of seismic waves trigger eruptions. This research topic tries to address some of the important open questions in interaction between stress field and volcanic eruption, though both review papers and new contributions.

Special Paper 498 contains 12 new scientific papers, assembled as part of an NSF-sponsored workshop in 2011. The work highlights study of persistently active volcanoes and their hazards, mostly in Central America. Such volcanoes are termed "open vents" by volcanologists, and they offer the chance to study active processes. Insight into how volcanoes work and how hazards might be mitigated are the goals of the work. Overall, the volume presents insight into hazards infrastructure collaborations and development for geoscientists and students.