Hostname: page-component-7c8c6479df-27gpq Total loading time: 0 Render date: 2024-03-19T09:02:30.055Z Has data issue: false hasContentIssue false

Central volcanoes as sources for the Antarctic Peninsula Volcanic Group

Published online by Cambridge University Press:  12 May 2004

Philip T. Leat
Affiliation:
British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
Jane H. Scarrow
Affiliation:
British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK

Abstract

From at least the Early Jurassic to the Miocene, eastward subduction of oceanic crust took place beneath the Antarctic Peninsula. Magmatism associated with the subduction generated a N-S linear belt of volcanic rocks known as the Antarctic Peninsula Volcanic Group (APVG), and which erosion has now exposed at about the plutonic/volcanic interface. Large central volcanoes from the APVG are described here for the first time. The structures are situated in north-west Palmer Land within the main Mesozoic magmatic arc. One centre, Zonda Towers, is recognized by the presence of a 160 m thick silicic ignimbrite, containing accidental lava blocks up to 25 m in diameter. This megabreccia is interpreted as a caldera-fill deposit which formed by land sliding of steep caldera walls during ignimbrite eruption and deposition. A larger centre, Mount Edgell-Wright Spires, is dominated by coarse-grained debris flow deposits and silicic ignimbrites which, with minor lavas and fine-grained tuffs, form a volcanic succession some 1.5 km thick. Basic intermediate and silicic sills c. 50 m thick intrude the succession. A central gabbro-granite intrusion is interpreted to be a high-level magma chamber of the Mount Edgell volcano.

Type
Papers—Earth Sciences and Glaciology
Copyright
© Antarctic Science Ltd 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)