Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up
CONTAINS OPEN ACCESS

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).
Chapter 2.2b Palmer Land and Graham Land volcanic groups (Antarctic Peninsula): petrology
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Published:May 27, 2021
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CiteCitation
Teal R. Riley, Philip T. Leat, 2021. "Chapter 2.2b Palmer Land and Graham Land volcanic groups (Antarctic Peninsula): petrology", Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up, J. L. Smellie, K. S. Panter, A. Geyer
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Abstract
Large-volume rhyolitic volcanism along the proto-Pacific margin of Gondwana consists of three major episodes of magmatism or ‘flare-ups’. The initial episode (V1) overlaps with the Karoo–Ferrar large igneous provinces at c. 183 Ma. A second (V2) episode was erupted in the interval 171–167 Ma, and a third episode (V3) was emplaced in the interval 157–153 Ma. The magmatic events of the V1 and V2 episodes of the Antarctic Peninsula are reviewed here describing major and trace elements, and isotopic (Sr, Nd, O) data from rhyolitic volcanic rocks and more minor basaltic magmatism. An isotopically uniform intermediate magma developed as a result of anatexis of hydrous mafic lower crust, which can be linked to earlier, arc-related underplating. The subsequent lower-crust partial melts mixed with fractionated mafic underplate, followed by mid-crust storage and homogenization. Early Jurassic (V1) volcanic rocks of the southern Antarctic Peninsula are derived from the isotopically uniform magma, but they have mixed with melts of upper-crustal paragneiss in high-level magma chambers. The V2 rhyolites from the northern Antarctic Peninsula are the result of assimilation and fractional crystallization of the isotopically uniform magma. This process took place in upper-crust magma reservoirs involving crustal assimilants with an isotopic composition akin to that of the magma. A continental margin-arc setting was critical in allowing the development of an hydrous, fusible lower crust. Lower-crustal anatexis was in response to mafic underplating associated with the mantle plume thought to be responsible for the contemporaneous Karoo magmatic province and rifting associated with the initial break-up of Gondwana.
- anatexis
- Antarctic Peninsula
- Antarctica
- assimilation
- basaltic composition
- correlation
- crust
- eruptions
- fractional crystallization
- gneisses
- Gondwana
- Graham Land
- igneous rocks
- Jurassic
- Karoo Supergroup
- large igneous provinces
- lower crust
- magma chambers
- magmas
- magmatism
- major elements
- mantle
- mantle plumes
- Mesozoic
- metamorphic rocks
- metasedimentary rocks
- paragneiss
- plate tectonics
- rhyolites
- rhyolitic composition
- rifting
- trace elements
- upper crust
- volcanic rocks
- volcanism
- Palmer Land
- Chon Aike Formation
- Mount Poster Formation
- Brennecke Formation
- Mapple Formation
- Sweeney Formation
- Jhort Formation
- Palmer Land Volcanic Group
- Graham Land Volcanic Group