On the considered transverse, stratigraphie and structural studies allow us to distinguish : A) 5 superincumbent units 1) A lower basement unit, which forms the real basal complex of Southern Vanoise massif, never display any post paleozoic cover. 2) An upper basement unit, showing same petrographies characteristics and drifted on the precedent by an early thrust underline by Permo-Triasic quartzites. This upper basement unit supports an adherent Jurassic cover and slices of brecciated " Ambin type " marbles. In spite of very dilacered aspect and because of their convergent facies , we purpose to see in these "Ambin type" series the autochtonous cover of the upper basement unit, taken off this one and its autochton jurassic cover by early alpine deformations. 3 ) The "Grande Hotte type" units, drifts on the precedent unit and which principally out crop at the East of the "Doron de Termignon" (Pierre Brune / Lanserlia / Coëtet / Chavière). We probaly find some nappe outlier in LanslebourgLanslevillard window, where the triasic serie may represent the base of the Grande Motte nappe. 4) Rocheure' s slices, which show tectonic superposition of two brecciated series, displaying same sedimentary characteristics as both for the " Plan des Nettes" and the "Chevril" series . This unit, drifts on the Lias " type Grande Motte " of the Pierre Brune unit, gives evidence of the intrabriançonnal position of the Grande Motte basin. 5) The Schistes lustrés nappe , with its basal evaporitic nappe (gypsum nappe), caps the precedents units . B) 3 ductiles deformations follow by the upwarping and fracturation of the massif. D1 the differents nappes take place, with formation of recumbent fold with NE-SW axis and W vergence . These folds duplicate the series and affect both basement and cover . Direction of nappe transport during this first stage is supposed through the NW. D1 take place under glaucophane green schist-facies metamorphism . D2 the massif was structured like a large penninic over fold through the North. The anticinal closure of this fold could be represented by the Grande Casse and Grande Motte massif . At last, this deformation seems to be non coaxial. D3 that is the classical backthrusting and backfolding phase of the internal Alps. It takes place after the growth of albite porphyroblasts of the greenschist-facies metamorphism (LP/LT) and shows two seps during a single phase of deformation. The succession of these two steps could be explained by the variations of the incremental strain associated to an encrease of deformation. It had involved, at first, backfolding through E or SE, and then backthrusting through S or SE, cutting out precedents structures . D4: the Southern Vanoise massif is folded like an anticlinal bulge, foliation is basculed to the East and late fractures cut out the youngest structures. This later phase only have a minor effect in comparison with the 3 precedent phases, and was not invistigated in this study.
