This piece of ancient compressed mud from the Stormhoek vineyards contains a broad stream of minerals. This typical rock is soft and brittle, easily accessible to vine roots.

Unlike animals, vines don’t search for food. Their roots grow all of their lives in an endless hunt for water. The mineral content of the water absorbed by the roots provides the nutrition they need.
If the vine is lucky, its roots take in water that has drained through mineral-rich soil.
The most complex soils are those with the widest range of minerals. These soils are sedimentary, created by the draining together of solid fragments of material from many origins, diluted in and carried by water.
They settle at the bottom of a lake or a sea and in time are compressed into rock by the weight of the water.
When this mudrock (shale) is lifted above the water surface by volcanic action, and the now exposed slabs of sedimentary rock are eroded by wind and rain, you are left with soil that has very complex mineral content.
The Stormhoek soils were deposited under water 1000 million years ago and uplifted 450 million years later making them the oldest soils containing vineyards anywhere in the world and presumably, one of the most complex