Land forms reach from the precipitous limestone Alps in the north to the
crystalline hilltops of the Niedere Tauern and further until the wooded low
mountain range of the Paleozoicum of Graz and the flat hills of the Styrian
tertiary basin.
To the south, the limestone Alps (Totes Gebirge, Hochschwab) are lined by a
narrow ribbon of older rock formations, which form the basis of the limestone
Alps. Among layers of paleozoic slate and carbonate, interspersed with volcanic
rocks, there are numerous deposits of important raw materials such as iron ore,
magnetite or talcum. The Styrian Erzberg mountain is the biggest mining area
in Austria. About 3 million tons of iron ore with a 32 % content of iron and a
2 % content of manganese are extracted here each year. Due to the content of
manganese, Styrian iron ore is a high-quality raw material.
Towards the south follows the crystalline of the Niedere Tauern and the Koralpe.
20 million years ago, the sea of the Hungarian Valley spread to the Alpine
region. The Styrian tertiary basin subsided and was flooded. In the west
Styrian basin lies the Köflach coal mine, where 127 million tons of coal have
been extracted since the 18th century.
Where the basin subsided at weak points of the earth´s crust, volcanic activity
erupted about 18 million years ago and basalt lava reached the earth´s surface
(where it carries now the Riegersburg and is found around Klöch). As a
consequence of the volcanic activity in the Styrian tertiary basin, there are
thermal springs, which are used for baths and heating.
Except for the Central Alps, big parts of Styria were free of ice. The common
loess layers of the Styrian basin consist of fine particles, which were blown
from the moraines and gravel surfaces.