The rocks shown on the Gebhardshagen Rock Trail are arranged in three groups according to their origin:

Scandinavian boulders of the Ice Age (No. 1 - 5):
These are the oldest rocks shown, they originate from the Scandinavian basement and were pushed to Salzgitter by the glaciers of the Ice Age.

Rocks that occur in the Harz Mountains (No. 6 - 13):
These are sedimentary and igneous rocks of the Harz. The Harz is part of the Variscan Fold Mountains and consists of diverse folded rock series of the Palaeozoic, into which various magmatic bodies have penetrated.

Rocks that occur in the Salzgitter area (No. 14 - 19):
Sedimentary rocks, mainly from the Mesozoic Era, can be seen here, which in earlier times were also extracted in quarries in the Salzgitter area and used as building material.

Rocks are divided into three main groups according to their formation.
The rock nature trail shows rocks from all three groups:

Sedimentary rocks or sedimentary rocks (nos. 3, 4, 6, 8, 9 and 14 - 19):
They are formed by the deposition of (rock) material in the sea or on land. Stratification can often be recognized.

Magmatic rocks or solidification rocks: Volcanites (No. 2, 7 and 13) and plutonites (No. 1 and 10 - 12):
They are formed from rock melts and are divided according to the position in which they solidify into volcanites = effusive rocks that solidify on the earth's surface and plutonites = deep rocks that solidify in the earth's crust. Due to slower cooling, plutonites have a much coarser mineral structure than the volcanites formed from rapidly cooling lava.

Metamorphic rocks or metamorphic rocks (No. 5, No. 2): They are formed by transformation from the previously mentioned rocks when pressure or temperature increases.