In the township of Barsac there are three types of terroir. Starting from the Garonne:

• Recent alluvial soils near the Garonne.
• Ancient alluvial soils and garonnais gravel of Günz in the areas close to the railway.
• The “Haut-Barsac” plateau, a layer of red earth 40 cm thick over a limestone plateau through which the roots of the vines descend to a depth of 10 metres.

The geology of the Sauternes area can be summarized in five words: gravel terraces mixed with silt ; the description of Barsac in six words : limestone watershed weathered into clay soils. Sauternes is a wine area of soft steps, with various exposures but generally facing north. The Barsac wine area is a very gentle watershed facing east.

Plateau of Haut-Barsac	Sauternes