Saint Etienne, January 8th, 2013
Dear Editors,
Please find enclosed a manuscript entitled “Contribution of AMS measurements in
understanding the migmatitic terrains of Pointe Géologie, Terre Adélie (East-Antarctica)” that
Bernard Henry, René-Pierre Ménot, Minoru Funaki, Guilhem Barruol and myself would like
to submit to Tectonophysics for publication.
This manuscript presents a detailed magnetic mapping using Anisotropy of Magnetic
Susceptibility (AMS) technique in Paleoproterozoic migmatitic terrains of Terre Adélie (East
Antarctica). AMS measurements allowed to better characterize the tectonic structure of the
crystalline basement that is built up by rocks affected by various degrees of partial melting
and then, devoid of clear markers of deformation. Data shows contrasted AMS signatures
between melanocratic layers on the one hand and felsic leucosomes, dykes and anatexites on
the other hand. It is related to a rheological contrast between the solid-state deformation
suffered by the oxide grains and their reorientation in a viscous flow during the aggregation of
felsic melt.
AMS measurements are in agreement with the model of deformation of a hot and weak
lithosphere converging toward a cooler Archean craton proposed by Gapais et al. (2008) from
metamorphic and field structures analysis and analogic simulations. In addition, the magnetic
structures map allows highlighting the role of the gravity-induced upwelling of a crust
undergoing partial melting.
The study under consideration is an original work, not published elsewhere or under
consideration for publication elsewhere. All authors have seen the manuscript and agree to its
submission to Tectonophysics.
Sincerely,
Jérôme Bascou
Jérôme Bascou
UFR Sciences et techniques, Université Jean Monnet, 23 rue du Dr. P. Michelon,
42023 Saint Etienne cedex 02 ; Tel 04 77 48 51 24 ; Fax : 04 77 48 51 08
courriel : jerome.bascou@univ-st-etienne.fr