Publication Date:
2017-10-17
Description:
Over the past decade, Australian, Norwegian and Russian marine surveys have collected integrated seismic,
gravity and magnetic data in the southern Indian Ocean. The more than 350,000 line-km of new airborne
and marine magnetic observations for the East Antarctic continental margin have been compiled into an
improved definition of crustal magnetic anomaly patterns. This compilation provides important new
constraints on the breakup processes and igneous activity related to the formation of the passive margin of
East Antarctica. The eastern sector of the map from Bruce Rise in the west to the D'Urville Sea in the east is
largely dominated by seafloor spreading magnetic anomalies. The ‘Adélie Rift Block’ of highly stretched and
extensively faulted continental crust is associated with a smooth anomaly fabric. Abrupt magnetic anomaly
changes along the oceanic-continent transition in the Cooperation Sea including the Enderby Basin Anomaly
extend for more than 1680 km from the Kerguelen Plateau towards the Cosmonaut Sea. Three sectors of the
East Antarctic continental margin exhibit pronounced disparities in the anomaly patterns that strongly
suggest different modes of seafloor formation. Strong positive seafloor magnetic anomalies mark the southern
margin of the Kerguelen Plateau, the Maud Rise and adjacent areas in the Riiser-Larsen Sea. The new compilation suggests that at least 300 km of the Enderby Basin and Shackleton Basin may be part of the
Cretaceous Kerguelen Volcanic Province and possibly maps an abandoned ‘fossil’ spreading center in the
central Enderby Basin. The majority of the published age models for the Enderby Basin and “Australian
sector” of the East Antarctic margin are not in agreement with the structural grain of magnetic anomalies
in the newly compiled map.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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