The Antarctic Peninsula is distinguished by late Neogene volcanic activity related to a series of northerly-younging ridge crest—trench collisions and the progressive opening of ‘no-slab windows’ in the subjacent mantle. The outcrops were amongst the last to be discovered in the region, with many occurrences not visited until the 1970’s and 1980’s. The volcanism consists of several monogenetic volcanic fields and small isolated centres. It is sodic alkaline to tholeiitic in composition and ranges in age between 7.7 Ma and present. No eruptions have been observed (with the possible, but dubious, exception of Seal Nunataks in 1893), but very young isotopic ages for some outcrops suggest that future eruptions are a possibility. The eruptions were overwhelmingly glaciovolcanic and the outcrops have been a major source of information on glaciovolcano construction. They have also been highly instrumental in advancing our understanding of the configuration of the Plio-Pleistocene Antarctic Peninsula Ice Sheet. However, our knowledge is hindered by a paucity of modern, precise isotopic ages. In particular, there is no obvious relationship between the age of ridge crest—trench collisions and the timing of slab-window volcanism, a puzzle that may only be resolved by new dating.
|Title of host publication||Volcanism in Antarctica|
|Subtitle of host publication||200 Million Years of Subduction, Rifting and Continental Break-Up|
|Editors||J. L. Smellie, K. S. Panter, A. Geyer|
|Publisher||Geological Society of London|
|Number of pages||20|
|Publication status||Published - 27 May 2021|
|Name||Geological Society London Memoirs|
|Publisher||Geological Society London|
The fieldwork on which this chapter is based was undertaken by MJH in 1985-1988. The authors thank the British Antarctic Survey for originally supporting our project. Andy Saunders is also thanked for additional information on the Argo Point outcrop, and we are grateful to Janet Thomson for permission to publish her photograph of Mt Benkert.