Comparison of this work with the geological maps of Ochagavia and Navascues [Puigdefàbregas and Sánchez Carpintero, 1978a,b] reveals several differences. The Minchale valley cross-section of Puigdefàbregas and Sánchez Carpintero [1978a] shows south vergent folding with a 500 m wavelength just south of the Ochogorri anticline, while in the field a continuous zone of some 2 km has been observed with north dipping beds without indication of any folding. Also, the Inzaga thrust has not been mapped in the Minchale valley by Puigdefàbregas and Sánchez Carpintero [1978a]. Another important difference, is the reappearance of the Paleocene platform carbonate south of the Ezcaurri anticline, which has not been reported by Puigdefàbregas and Sánchez Carpintero [1978a]. The work presented in here shows stacking of several thrust sheets between the village of Isaba and Urzainqui, while the geological map and cross section III and IV of Ochagavia show only two thrusts [Puigdefàbregas and Sánchez Carpintero, 1978a]. Although the presence of several megabeds superposed on top of each other can be recognised on the Ochagavia map, the sequence of megabeds is interpreted to be of sedimentary origin (i.e. sequence of different megabeds) [Puigdefàbregas and Sánchez Carpintero, 1978a].

When looking at the work of Labaume et al. [1985], there more similarities to be discovered. First of all, the style of interpretation is much more alike, with clear defined low angle thrusts and décollement levels (see Fig. 4). There is, however, one important difference. Labaume et al. [1985] have interpreted the first massive carbonate unit to the south of the Ezcaurri anticline (see megabed 1 in Fig. 4 between Isaba and Ezcaurri) to be the first megabed of the Hecho group and be located on the southern flank of the Ezcaurri anticline. In the work presented here, this outcropping formation has been interpreted as the reappearance of the Paleocene carbonate platform (Ager formation). Numerous field measurements have indicated that a tight syncline is present between this outcropping formation and the Ezcaurri anticline in the north, which gradually widens towards the WNW, due to the plunge of its fold axis towards the WNW.

It is possible to correlate some of the major structures mapped by Teixell and García-Sansegundo [1994] , Teixell et al. [1994] and Teixell [1996] in the Anso valley with structures in the Belagua valley to the west. Several folds in the Sierras Interiores, such as the Arniota, San Zolo and Ezcaurri anticlines, and the Ardibidipicua syncline can be correlated with folds in the Anso valley. Also, the Urzainqui, Ardibidipicua and Roncal thrusts can be correlated with structures in the Anso valley. However, some structures in the east are not outcropping in the west, due to the westward plunge of the axial zone of ~ 15°. For example, the décollement level of the Larra floor thrust has not been observed in the Belagua region.