Conceptual model after the two former structural interpretations. On these two sketches, the black continuous lines show the observable features that are extrapolated in dashed thin lines to show sub-surface and “over-surface” consequences of the structural models of the two authors. (A) Interpretation of Calembert (1952): this author identified a hinge, in jurassic and lower cretaceous levels that he interpreted to be the hinge of a recumbent syncline, whose northern flank represents the reverse serie of the GP. There is no allochthony of the GP. (B) Interpretation of Mattauer (1958): the GP allochthonous reverse package is issued from the same structural unit than the para-autochthonous in normal polarity below, i.e., the “complex A” of Mattauer (1958). As lateral equivalent of Aïn el Hadjela nappe, he considered it to come from an undefined area north of the line RA-SAK. This “complex A” has been further thrust by the upper Tellian nappes during the Miocene.