Abstract Petrological investigations over the past 30 years have significantly advanced our knowledge of the origin and evolution of magmas emplaced within and erupted on top of the Antarctic Plate. Over the last 200 myr Antarctica has experienced: (1) several episodes of rifting, leading to the fragmentation of Gondwana and the formation by c. 83 Ma of the current Antarctica Plate; (2) long-lived subduction that shut down progressively eastwards along the Gondwana margin in the Late Cretaceous and is still active at the northernmost tip of the Antarctic Peninsula; and (3) broad extension across West Antarctica that produced one of the Earth's major continental rift systems. The dynamic tectonic history of Antarctica since the Triassic has led to a diversity of volcano types and igneous rock compositions with correspondingly diverse origins. Many intriguing questions remain about the petrology of mantle sources and the mechanisms for melting during each tectonomagmatic phase. For intraplate magmatism, the upwelling of deep mantle plumes is often evoked. Alternatively, subduction-related metasomatized mantle sources and melting by more passive means (e.g. edge-driven flow, translithospheric faulting, slab windows) are proposed. A brief review of these often competing models is provided in this chapter along with recommendations for ongoing petrological research in Antarctica.

Abstract Neogene volcanism is widespread in northern Victoria Land, and is part of the McMurdo Volcanic Group. It is characterized by multiple coalesced shield volcanoes but includes a few relatively small stratovolcanoes. Two volcanic provinces are defined (Hallett and Melbourne), with nine constituent volcanic fields. Multitudes of tiny monogenetic volcanic centres (mainly scoria cones) are also scattered across the region and are called the Northern Local Suite. The volcanism extends in age between middle Miocene ( c. 15 Ma) and present but most is <10 Ma. Two centres may still be active (Mount Melbourne and Mount Rittmann). It is alkaline, varying between basalt (basanite) and trachyte/rhyolite. There are also associated, geographically restricted, alkaline gabbro to granite plutons and dykes (Meander Intrusive Group) with mainly Eocene–Oligocene ages (52–18 Ma). The isotopic compositions of the plutons have been used to infer overall cooling of climate during the Eocene–Oligocene. The volcanic sequences are overwhelmingly glaciovolcanic and are dominated by ‘a‘ā lava-fed deltas, the first to be described anywhere. They have been a major source of information on Mio-Pliocene glacial conditions and were used to establish that the thermal regime during glacial periods was polythermal, thus necessitating a change in the prevailing paradigm for ice-sheet evolution.

Abstract Cenozoic magmatic rocks related to the West Antarctic Rift System crop out right across Antarctica, in Victoria Land, Marie Byrd Land and into Ellsworth Land. Northern Victoria Land, located at the northwestern tip of the western rift shoulder, is unique in hosting the longest record of the rift-related igneous activity: plutonic rocks and cogenetic dyke swarms cover the time span from c. 50 to 20 Ma, and volcanic rocks are recorded from 15 Ma to the present. The origin of the entire igneous suite is debated; nevertheless, the combination of geochemical and isotopic data with the regional tectonic history supports a model with no role for a mantle plume. Amagmatic extension during the Cretaceous generated an autometasomatized mantle source that, during Eocene–present activity, produced magma by small degrees of melting induced by the transtensional activity of translithospheric fault systems. The emplacement of Eocene–Oligocene plutons and dyke swarms was focused along these fault systems. Conversely, the location of the mid-Miocene–present volcanoes is governed by lithospheric necking along the Ross Sea coast for the largest volcanic edifices; while inland, smaller central volcanoes and scoria cones are related to the establishment of magma chambers in thicker crust.

Abstract Erebus volcano, Antarctica, is the southernmost active volcano on the globe. Despite its remoteness and harsh conditions, Erebus volcano provides an unprecedented and unique opportunity to study the petrogenesis and evolution, as well as the passive and explosive degassing, of an alkaline magmatic system with a persistently open and magma-filled conduit. In this chapter, we review nearly five decades of scientific research related to Erebus volcano, including geological, geophysical, geochemical and microbiological observations and interpretations. Mount Erebus is truly one of the world's most significant natural volcano laboratories where the lofty scientific goal of studying a volcanic system from mantle to microbe is being realized.

Abstract Mount Melbourne and Mount Rittmann are quiescent, although potentially explosive, alkaline volcanoes located 100 km apart in Northern Victoria Land quite close to three stations (Mario Zucchelli Station, Gondwana and Jang Bogo). The earliest investigations on Mount Melbourne started at the end of the 1960s; Mount Rittmann was discovered during the 1988–89 Italian campaign and knowledge of it is more limited due to the extensive ice cover. The first geophysical observations at Mount Melbourne were set up in 1988 by the Italian National Antarctic Research Programme (PNRA), which has recently funded new volcanological, geochemical and geophysical investigations on both volcanoes. Mount Melbourne and Mount Rittmann are active, and are characterized by fumaroles that are fed by volcanic fluid; their seismicity shows typical volcano signals, such as long-period events and tremor. Slow deformative phases have been recognized in the Mount Melbourne summit area. Future implementation of monitoring systems would help to improve our knowledge and enable near-real-time data to be acquired in order to track the evolution of these volcanoes. This would prove extremely useful in volcanic risk mitigation, considering that both Mount Melbourne and Mount Rittmann are potentially capable of producing major explosive activity with a possible risk to large and distant communities.

Abstract Although the present environmental conditions on Mars prohibit the generation of significant volumes of liquid water, observations of several very young landforms, such as gullies and recurrent slope lineae, have been interpreted as signals for aqueous processes. To explore the range of conditions under which such features can be formed on Earth, a field site in northern Victoria Land, East Antarctica, was geomorphologically investigated. Despite the small size of the ice-free area, the site displays gullies, water tracks and other traces of liquid water. The gullies show clear evidence of sediment transport by debris flows, and are typical of paraglacial processes on steep slopes in a recently deglaciated area. Water tracks appear in different forms, and seem to recur seasonally in the austral summer. Melting of snow and surface glacier ice is the major water source for both debris flows and water tracks. The observations presented here highlight the potential for hyperarid polar deserts to generate morphogenetically significant amounts of meltwater. The gullies are morphologically analogous to Martian gullies, and water tracks on steep slopes appear very similar to recurrent slope lineae. The observations suggest that even small ice-free sites in continental Antarctica may enable observations which can serve as a basis for working hypotheses in Mars analogue studies, and future field work should consider more areas in Antarctica in addition to the McMurdo Dry Valleys to search for Mars analogue landforms.

Abstract We report on a decade of fieldwork designed to determine the conditions required for erosion of Mars-like gully channels in the McMurdo Dry Valleys (MDV) of Antarctica. We have outlined the major factors in the morphological evolution of gullies in the Inland Mixed Zone of the MDV: (1) the distribution of ice sources; (2) the temporal aspects of ice melting; and (3) the relative significance of melting events in gullies. We show that significant erosion of gully channels can be achieved if geometrical and environmental conditions combine to concentrate ice where it can rapidly melt. In contrast, annual melting of surface ice and snow deposits during late-season discharge events contribute to transport of water, but flux rarely surpasses the infiltration capacity of the active layer. These small discharge events do not erode channels of significant width. Even when the flux is sufficient to carve a c. 10–20 cm deep channel during late summer (January–February) runoff, these small channels seldom persist through multiple seasons, because they are seasonally muted and filled with aeolian deposits. We briefly discuss the application of these results to the study of gully systems on Mars. Supplementary material: Eight videos showing activity and events are available at https://doi.org/10.6084/m9.figshare.c.3935992