The existence of an early NE-directed nappe in the NW Himalaya was first documented by Vannay (1993); Steck et al. (1993); Epard et al. (1995) and Vannay and Steck (1995). Their arguments are mainly based on a very detailed structural analyses of the Tandi Syncline and the distribution of the regional metamorphism. Southeast Zanskar is only marginally affected by the phase D1. Preserved structures associated with this phase are scarce and restricted to the southwestern part of the studied area. Deformation is documented by a schistosity S1 and by tight isoclinal folds F1. The foliation and folds associated with D1 overprint the sedimentary bedding S0. No thrust plane is associated with D1 in this area. A precise description of the microstructural and metamorphic evidences for this phase is given in Chapter 5.2.