Frontiers and Opportunities in Antarctic Geosciences * Certosa di Pontignano * 29-31 July 2004
Recent Aeromagnetic and Deep Electromagnetic Surveys in
Northern Victoria Land
E. ARMADILLO1*, E. BOZZO1, G. CANEVA1, F. FERRACCIOLI2, G. TABELLARIO1
1 – DIPTERIS – Università di Genova, V.le Benedetto XV, 5, Genova, Italy
2 – British Antarctic Survey, Cambridge, UK
*Corresponding author (egidio@dipteris.unige.it)
Extensive international aeromagnetic investigations have been performed over the last two decades to assist in regional
geological mapping and interpretation over Northern Victoria Land (East Antarctica). Recently, cooperative exploration
projects have been focused on the two major tectonic elements of the region: the Transantarctic Mountains (TAM),
forming the uplifted flank of the West Antarctic Rift System (WARS), and the Wilkes Subglacial Basin (WSB), a broad
depression recognized as the major subglacial feature in the hinterland of the TAM. Also the relationships between the
three fault-bounded tectono-stratigraphic terranes (Robertson Bay, Bowers and Wilson Terrane) of Early Paleozoic age
recognised over NVL have been recently investigated. We will review here the main goals and results of four recent
aeromagnetic and deep electromagnetic surveys performed in the frame of the BACKTAM, MAGANTER, TIMM and
WIBEM projects.
During the joint German-Italian Antarctic campaign 1999-2000 (BACKTAM project) geophysical investigations were
performed over northern Victoria Land, Oates Land and George V Land (Bozzo & Damaske, 2001). The new
aeromagnetic maps (Damaske et al., 2003; Ferraccioli et al., 2003) will provide further insight into the TAM and into
the previously unexplored northernmost edge of the WSB. Geomagnetic depth sounding investigations (Armadillo et
al., 2004) were focused on the glaciated Rennick Graben and the adjacent fault-bounded terranes. Integrated modelling
across the Rennick Glacier (gravity, magnetic, seismic and electromagnetic) will further lighten the deep structure of
the Graben and the adjacent fault-bounded terranes, adding more constraints to the interpreted geological models (e.g.
Finn et al., 1999; Ferraccioli et al., 2002; Rossetti et al., 2003).
During the 2001-2002 Italian Antarctic campaign the MAGANTER aeromagnetic survey was performed north of
Mariner Glacier, focusing upon the spatial distribution of Cenozoic plutons, dyke swarms, and volcanoes in relation to
inferred intra-plate strike-slip fault belts, which have recently been proposed to control magma genesis and
emplacement (e.g Rocchi et al., 2002). The new map reveals that there is no aeromagnetic evidence for major Cenozoic
alkaline plutonism over the Admiralty Mountains Block. Therefore major tectonomagmatic segmentation with respect
to the Southern Cross Block (Ferraccioli & Bozzo, 1999) is suggested.
An high-resolution aeromagnetic survey was performed in the frame of the TIMM project during the 2002-2003 Italian
Antarctic campaign over Mount Melbourne volcano. The regional significance of Mt. Melbourne is high because of its
key location at the transition between the uplifted TAM and the WARS. The new aeromagnetic anomaly images now
map the largely ice-covered magmatic and tectonic patters in the Mt. Melbourne volcano area with an unprecedented
degree of detail.
The WIBEM project (2003-2004 Italian Antarctic campaign) has focused on the eastern margin of the Wilkes
Subglacial Basin, providing constraints both upon the nature of the Basin itself and upon relationships between the
Basin, the Transantarctic Mountains and the inherited structural framework at the margin of the Craton. By analysing
the magnetic anomaly patterns we will also address regional continuity of the previously proposed fault zone (e.g.
Ferraccioli & Bozzo, 2003).
New data will be collected in the 2005/06 campaign by a new cooperative exploration project, called WISE (WIlkes
Basin/Transantarctic Mountains System Exploration), involving PNRA and BAS. WISE will explore the boundary
region between East and West Antarctica over part of the TAM and WSB by collecting new airborne geophysical and
ground geophysical data, coupled with new geological, AFT, structural and petromagnetic investigations. We aim to
better constrain structural architecture of the WSB and TAM system, assess if thick Cenozoic sediments could be
present in the northern WSB, and study possible segmentation of the TAM into discrete tectonic blocks.
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