Fig. 4

a general view of St. Angel Cave showing an east-verging fold. The church remains in the bottom centre of the picture; b inside St. Angel church. Lombard tomb is visible at the bottom right corner; c decorative arches belonging to the 10th–11th century; d Christogram; e details of the decorative arches of the thirteenth century; f general view of the Eastern side of St. Angel church remains; g rock spur showing handmade groove to collect water percolation tubs (orange and pink dotted line) crosscut by the church wall on the right. North is shown in Figs. 2, 7. h details of the tectonic discontinuity (top of the hammer) dipping 20° toward NNE. The karstic holes corresponding to the water spring line (green dotted line) settled on the tectonic contact. Some water tubs are visible below the tectonic contact (orange dotted line) where grooves converge (pink dotted line).