The scenic landscape of Austria has been significantly shaped by the main geological units: the highlands of the Waldviertel and Mühlviertel regions form part of the Bohemian Massif in the north, followed by the undulating hilly Alpine Foreland with great valleys and basins in the east, and finally the mountainous Alps, which extend for over 500 km lengthwise across the country.
The Eastern Alps are part of a large band of mountains that extends from the Riviera to Vienna. From a geological perspective, these mountains were formed by the convergence of the Adriatic and Eurasian Plates, which crumpled and folded upwards as they moved together. The Alps continue beneath the basins in the east of the country, covered by sediments that are up to 5000 metres thick, before re-emerging in the Carpathians and Dinarides. The formation of these major geological structures can be traced back to tectonic processes. Hundreds of millions of years ago, as the rocks were being formed, these processes transformed the distribution of land and water, displaced and broke up continents, opened seas and closed them up, and caused mountains to form before eroding them away again.
However, rocks and the progression of tectonic boundaries also have a direct, smaller-scale impact on the landscape. Soft, easily-weathered rocks tend to give rise to gentle terrain, while hard, brittle types of rock usually form rugged mountainous landscapes and steep cliffs. Valleys often follow the line of tectonic faults. However, in areas of soft rock, rapid erosion by water can also cause the formation of canyons and almost-vertical river banks – in contrast to areas with a hard, rocky substratum, where minimal differences in elevation and specific climatic conditions tend to result in gently rolling landscapes. From a more recent geological perspective, the great climatic fluctuations of the Quaternary played a significant role in shaping the landscape in the Alps. Referred to as an “ice age”, the Quaternary is characterised by at least four glacial phases. The abrasive force of the great glaciers and frost shattering caused large amounts of rock to be eroded. Gravel terraces were formed by the meltwaters, which caused erosion on the one hand, and deposition of sediments on the other. Rock dust also
blew off the barren mountains and settled in the forelands as loess. However, the land is not only shaped by the composition of rocks, tectonic boundaries, the rise and fall of the land and climatic change. Other factors, such as vegetation and human intervention, also contribute to the landscape’s character.
Since the main rock formations primarily traverse Austria from side to side, and the main wine-growing regions form an arc in the east of the country, almost all types of rock can be found in the country’s vineyards. It is precisely this that makes Austria’s viticultural landscape so diverse and exciting!
Rocks can differ greatly in terms of their cohesive properties and are roughly divided into two categories: consolidated hard rock or unconsolidated rock. The soils of around 70% of Austrian vineyards are unconsolidated (sedimentary), while the remaining 30% of vineyards grow on soils derived from consolidated (hard) rock.
Austria’s consolidated rocks belong to the following major geological units:
- the Moldanubian and Moravian zones in the Bohemian Massif region, composed of crystalline rocks from the Proterozoic and Palaeozoic
- the Helvetic zone and the cliffs of the Waschberg zone, formed of sedimentary rocks from the Mesozoic and early Cenozoic
- the Penninic zone, formed from the rocks of an ocean that existed in the Mesozoic and early Cenozoic. On the northern edge of the Eastern Alps lies the Penninic flysch zone. Similar rocks are found in a transformed (metamorphic) state in the region of the Central Eastern Alps where they crop out in tectonic windows below the Austroalpine nappes
- the Austroalpine nappes, formed from sedimentary rocks from the late Palaeozoic, Mesozoic and early Cenozoic in the Northern Calcareous Alps and the Gosau Group and from transformed (metamorphic) rocks and rock deposits (sedimentary rocks) from the Proterozoic, Palaeozoic and Mesozoic, which form the parent material of the Central Eastern Alps.
Austria’s unconsolidated rocks belong to the following geological units:
- the Molasse zone in the foothills of the Alps, formed from sedimentary rocks from the early and late Cenozoic (Palaeogene and Neogene) up to about 7 million years ago
- inner Alpine basins such as the Vienna Basin, Styrian Basin and Pannonian Basin, composed of sedimentary rocks from the Cenozoic (Neogene) up to about 2.6 million years ago
- deposits from the most recent geological period, the Quaternary, which are concentrated in the Molasse zone and in the basins, but which also overlap onto areas of consolidated hard rocks.
The following consolidated rocks also occur within the unconsolidated rock areas:
- solidified sands, gravels and rock debris that have cemented into sandstone, conglomerate or breccia
- Leitha limestone
- volcanic rocks in the Styrian Basin
The periods in the Earth’s history are broken down into the following time spans:
- the Proterozoic: more than 541 million years ago
- the Palaeozoic: 541–253 million years ago
- the Mesozoic: 253–66 million years ago
- the Cenozoic: 66 million years ago until the present day. (The Neogene/Quaternary are considered to have begun 2.6 million years ago, while the Pleistocene and Holocene started 10,000 years ago and are still continuing today.)