At the same time as the Allgäu strata, the variegated Jurassic limestones or variegated threshold limestones were formed. 190 million years ago , the colored Jurassic limestones were formed on the higher sill areas of the Jurassic sea. Compared to the deeper basins, very little mud was deposited here, almost 100 m deep.
Variegated Jurassic limestones are red, greenish and white limestones. The red coloration is due to the red iron oxide hematite finely distributed in the rock. It can only form if there is enough time at the bottom of the sea for the iron in the mud to combine with the oxygen in the water.
Since Roman times, these beautiful, brightly colored Jurassic limestones have been quarried in numerous quarries and used as colored marble in many ways (Lechtal Baroque, 18th century churches, castles). By polishing the colored Jurassic limestones become beautiful ornamental stones.