Tuesday, 28 August 2007 - 1:30 PM
2.P1.D-1
Triassic-Jurassic sediments and multiple volcanic events in North Victoria Land, Antarctica: A revised stratigraphic model
Robert Schöner1, Lothar Viereck-Götte1, Jörg Schneider2, and Benjamin Bomfleur3. (1) Institut für Geowissenschaften, Friedrich-Schiller-Universität Jena, Burgweg 11, Jena, 07749, Germany, (2) Institut für Geologie, TU Bergakademie Freiberg, Bernhard-von-Cotta Str. 2, Feiberg, 09596, Germany, (3) Geologisch-Paläontologisches Institut, Westfälische Wilhelms-Universität Münster, Hindenburgplatz 57, Münster, 48143, Germany
Field investigations in North Victoria Land, Antarctica during GANOVEX IX (2005/2006) allow the revision of the Triassic-Jurassic stratigraphy of ~300 m thick continental deposits in between the crystalline basement and the Kirkpatrick lava flows of the Ferrar Group. The lower stratigraphic unit (Section Peak Formation) is characterised by braided river-type quartzose sandstone deposits with intercalations of shale and coal occurring at the top. It is overlain by a homogeneous unit of reworked silicic tuffs (new informal name: "Shafer Peak Formation"). These deposits can be correlated with parts of the Hanson Formation in the Central Transantarctic Mountains. Clastic products of mafic volcanic eruptions, formerly described as a separate stratigraphic formation (Exposure Hill Formation), occur within local diatreme structures as well as intercalated in multiple stratigraphic levels within the sedimentary succession. These dominantly hydroclastic eruptions are the first subaerial expression of Ferrar magmatism.