Klaus is so to speak the continuation of Achleiten, however, it is separated by a path that serves as a boundary, which also represents a geological fault. The name can be followed back to the old term "Kleyss" and designates a constriction; this is self-explanatory when looking at the old road to Wachau leading along the Klaus vineyard.

Soil Profile Klaus - Migmatite-Amphibolite

"Klause refers to a gorge-like narrow pass through a valley in the Alps. It is thus no wonder that the steep slope between the Danube and Achleiten was given the name Klaus.
Migmatite-amphibolite dominate in the terrace vineyards of the upper Klaus. In contrast, the lower Klaus is home to paragneiss. Paragneisses are also metamorphic rocks, but in contrast to migmatites, they were not subject to partial melting.

Underneath the sandy, stony topsoil in the profile, the amphibolite character dominates, visible by the dark-coloured rock. The white coatings are carbonates that were precipitated during the course of soil formation. The carbonate itself probably comes from the glacial loess cover, which, after being dissolved during the course of weathering, was precipitated in the cracks of the rock as a white coating. The Klaus is one of the best Riesling slopes in the Wachau."

Soil Profile Klaus - Paragneis

The Klaus vineyard is practically synonymous with “Wachau Riesling”. To be sure, typical Wachau Rieslings are also cultivated on many other slopes. Yet the Klaus Rieslings were the first to emerge in the success story following 1945.
As in lower Achleiten, migmatite-amphibolite dominates the soil here, a hornblende-rich rock partially subjected to melting during the Variscan Orogeny. Paragneiss, a metamorphic rock formed from sediment, is also found here. The features typical of paragneiss dominate the profile shown here. A generous fine-soil cover ensures an adequate supply of water and nutrients, and the fissures in the weathered rock allow the vine roots to penetrate to a deep level.
Both migmatite-amphibolite and paragneiss weather to form sandy, base-rich soils that have a neutral pH level and allow good drainage.