Spotted marl

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As spot marl geologists call a dark spotted marl the northern Limestone Alps , the most common in the Allgäuer- and Lech Valley Alps on the Austrian-German border in evidence-often occurs in the vicinity of Allgäu layers and main dolomite . As a result of the ceiling construction in the Alps, it also occurs further to the south and east. a. in the Lienz Dolomites as well as in Lower and Upper Austria , and sometimes even in the subsoil of the Samnaun group , for example at the Stammerspitz .

In the Allgäu Alps - as here at the Jochspitze - the spotted marl often forms the subsoil of the peaks made of harder dolomite.

The sedimentary rock was mainly formed in the Lower Jurassic (200 to 175 million years ago), which is also called Lias, and partly also in the subsequent Dogger . This is why one often speaks of the Lias marl .

It often forms the subsoil of dolomite rocks ( e.g. on the Allgäu Jochspitze ) or their rock boundary. This neighborhood leads to striking contrasts in terrain and vegetation in the Lechtal Alps, for example . The Lechtal dolomite forms highly fragmented peaks and sharp-edged scree slopes , while the spotted marl occurs in yellowish, brittle mountains of rubble and, at medium heights, represents a fertile subsoil for dense, green mats.

In the west of the Walsertal mountains , some peaks (e.g. Heiterberg or Elferkopf ) are built from spotted marl, while flysch predominates in the northeast and main dolomite in the south (e.g. on the Widderstein ).

Some mountains with marl as the main rock are z. B.:

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