Ripple marks are natural waves on the rock surface. Some millions years ago, the movement of water left waves on the sediment of beaches or pools. Nowadays, the old waved shape remains as a fossil on the sedimentary rock surface. The same shape is found at present on the mud or the sand of the water sides in case of waves or turbulent flow. Marine sandstones from Eocene period in the district of Bages often make up their surface with beautiful ripple marks.
In the images 1st and 2nd, ripple marks on the explotation surface of old quarries in El Mal Balç (Manresa) that proof their origin as a water sediment.
In the images 3rd and 4th, ripple marks also on the explotation surface of another old quarry near to the waterfall of Balçamuller or El Gall from the stream of Castellet.
[photos Jordi Badia]
- See the article Manresa geosites, in Catalan, by Jordi Badia.