Heel collar

The Gola do Salto drop is caused by the combination of two geological faults with different orientations. While one has a N-S direction and is responsible for the straight alignment of the river in this region, the other has a NE-SW direction and determines the orientation of the drop. This combination raised the block upstream of the NE-SW fault, allowing the formation of the mighty waterfall. Thus, this geosite is an example of the great influence that geological faults have on the definition of watercourses. Downstream from the waterfall we find several giant marmitas (rounded depressions in the river’s rocky bed) sculpted by the strong erosive action of the wild waters of the Paiva River, which become even more energetic at Gola do Salto, and by the sediments transported by the river. Over time, the depressions become wider and deeper. In turn, the sediments found inside the marmitas become increasingly rounded. At this geosite and in its surroundings it is possible to see clast-supported metaconglomerates made up essentially of quartz clasts, quartzite and some schist correlated with the S. Domingos Formation. The clasts are generally subrounded and vary greatly in size, sometimes reaching 5 centimetres in diameter. The deposition of sands around 600 million years ago in a coastal environment (close to the beach area) would have allowed the initial formation of a sedimentary rock called sandstone. Later, the quartz crystals that made up the mineralogical composition of this rock recrystallized due to metamorphism, forming quartzite rocks.