TITLE:
Intraplate Transtensional Tectonics in the East Antarctic Craton: Insight from Buried Subglacial Bedrock in the Lake Vostok—Dome C Region
AUTHORS:
Paola Cianfarra, Francesco Salvini
KEYWORDS:
Intracratonic Tectonics; Numerical Modelling; East Antarctica
JOURNAL NAME:
International Journal of Geosciences,
Vol.4 No.9,
November
29,
2013
ABSTRACT: This study presents the results of forward numerical
models of a series of sections of the Aurora Trench (East Antarctica) derived
from radio echo-sounding data that allowed to reconstruct the 3D shape of the
Aurora Fault, a crustal listric normal fault characterized by a length
exceeding 100 km. A similar extensional fault setting allows to replicate the asymmetric
buried morphology of the magnetic basement at the Lake Vostok depression
derived by the available gravity and magnetic profiles. Both the Aurora and
Vostok listric fault reach their basal decollment at 34 km depth, possibly the
base of the crust in this intracratonic environment. Integration of these
results with the existing geologic interpretations of the tectonic origin of
the Concordia Trench by normal faulting allowed to frame the Concordia, Aurora
and Vostok normal faults within an intraplate transtensional corridor with a
left-lateral movement component. The westward projection of the proposed
strike-slip deformation belt may develop in correspondence of an older tectonic
lineament stretching from the Eastern flanks of the Gamburtsev Subglacial Mts
to the Lambert rift and characterized by a poly-phased complex tectonic
history. The possible Cenozoic reactivation of these structures is discussed in
the paper.