In the Permian geological period (about 296-251 million years ago) the first sandstone formations, some 100 metres thick, were deposited in the area of today's Palatinate Forest; in particular, the rock units of the Rotliegendes and the Zechstein (about 256-251 million years ago) are important. At the beginning of the Germanic Triassic, i.e. from the Lower to the beginning of the Middle Triassic, there was (about 251-243 million years ago) a desert-like climate, so that as a result of further depositions of sand, rock layers of up to 500 metres thickness were formed. This led "inter alia", through the addition of iron oxide, to a variable colouration of the rock strata - hence the name "bunter" sandstone ("bunter" being German for "coloured") - and, depending on the type and binding of the material, (clay-bound sandstone as opposed to silicified quartz sandstone) to the formation of rock layers of different hardness. This resulted in the subgroups of lower, middle and upper bunter sandstone. These bunter sandstone formations were buried by various types of sediments in the adjacent sections of muschelkalk (243-235 million years ago) and keuper (234-200 million years ago), and also during the Jurassic (200-142 million years ago) and Cretaceous (142-66 million years ago).