Priorat has a soil type very rare in the Iberian Peninsula. It is a type of slate from the Carboniferous period occupying much of the center of the region. Although different slates from around the world can vary in color and consistency, that found in Priorat is a very distinctive dark gray, brittle metamorphic rock that flakes into smooth, flat sheets. It is created when shales and clays are altered by low-grade regional metamorphism at low temperatures and moderate pressures (over hundreds of millions of years).
Here it is known as llicorella or llecorell. This word comes from the Celtic Likka, meaning stone, but its origin is linked to the expression “llécol” used to indicate mood, taste, pastiness, and “earthy” notes. When applied to wines the “earthiness imparted” takes on a true significance.
Slate, despite its hard appearance, is ultimately a fragile stone, formed by thin sheets that are separated with relative ease. The grapevine’s roots are forced to push with great effort to steer through this stony subsurface in search of the vital nutrients and water so essential in the production of great fruit.
The makeup and flat shape of the dark stone dark also seems to favor some reflection of strong sunlight and offers some protection to the vineyard by reducing evaporation.