The folds in mountain Borina are the most spectacular view of the abrupt anticline-fault of Santa Maria d’Oló.
The anticline-fault of Santa Maria d’Oló is a 12 km length, lining SW to NE, potent geological structure that crosses south from this village. The stream of Oló flows parallel and close to the anticline axis, in its SE side. The NW side that locates the village of Santa Maria d’Oló is smooth or flat. On the other hand, the lift SE side displays tilt, then out of shape rock layers, up to vertical or or folded when close to the fault plain and anticline axis. The folds in mountain Borina which are dug out by the stream of Oló beautifully show the arrangement of the SE side of anticline of Santa Maria d’Oló.
The anticline-fault of Santa Maria d’Oló is continued by the anticline-fault of Guix, in Sallent, that’s smaller. Both are the most southern geological structures that were originated by the tectonic forces that lift the Pyrenees, plus the plasticity of the saline geological formation Cardona beneath. The anticlines facilitate the outcrop of older strata. 1,5 km NE from Borina mountain, in same SE side of the anticline, the gipsy, grey mudstones laying above the salt of geological formation Cardona outcrop. Therefore, it’s not so surprising to find the Salty spring of Oló, as salty as sea water, in the left riverside of the stream of Oló, near to the village.
In 2010, the department of Environment from govern of Generalitat of Catalonia enlarged the Moianès Natural Interest Area to scope the Salty spring, the stream and the beautiful anticline-fault of Santa Maria d’Oló.
[photo Jordi Badia]