The geology of Alsace is a veritable mosaic of soils, madeup of granite, limestone, schist and sandstone. Facing mainly
south or south-east, the vineyards cover about 37,000 acres total. This diversity of vineyard soils has no equivalent anywhere in France. 50 million years ago, both the Vosges and the Black Forest (in Germany) were a single massif, and when it collapsed the Rhine plain was formed. The Alsace vineyards are situated along the fault line between the remaining massif of the Vosges and the plain, and benefit from the soil mosaic created of the collapsed ancient upper layers.