Bas hill
Turó d’en Bas is a peak located in the municipality of Santa Margarida de Montbui. It has a height of about 50 meters above the Anoia River (350 meters above sea level).
Much of the Ódena basin is littered with similar geological formations made up of hillocks of bluish- grey earth that are strongly eroded and furrowed by deep ditches or gullies.
These bluish soils, known as marls, were formed on the seabed and are therefore rich in mollusc, echinoderm, coral and foraminifera fossils. They are part clay, part calcium carbonate and in some places can be up to 600 meters thick.
The dissolution of the carbonates releases the clay and facilitates erosion, forming the characteristic gullies. In this state, the marls are called "badlands", where, because of their aridity, no plants grow.
Pictures
At the bottom, Bas hill