Keuper in the context of "Black Jurassic"

The Thuringian Basin (German: Thüringer Becken, pronounced [ˈtyːʁɪŋɐ ˈbɛkn̩]) is a depression in the central and northwest part of Thuringia in Germany which is crossed by several rivers, the longest of which is the Unstrut. It stretches about 60 kilometres (37 mi) from north to south and around 120 kilometres (75 mi) from east to west. Its height varies from about 150 to 250 m above sea level (NN).

The Basin is surrounded by a wide outer girdle of limestone (Muschelkalk) ridges (including Hainich, Dün, Hainleite, Hohe Schrecke, Schmücke, Finne), and to the southwest by the Thuringian Forest and to the southeast by sharply divided terraces (the Ilm-Saale and Ohrdruf Muschelkalk plateaus, and the Saale-Elster Bunter sandstone plateau). The Thuringian Basin belongs to the triassic period, during which horizontal beds of Bunter sandstone, Muschelkalk and Keuper were laid down. Below those lie the salt and gypsum layers of Magnesian Limestone (Zechstein). In the Cenozoic era the surrounding ridges were uplifted, whilst the Thuringian Basin sank to form a saucer-shaped depression.

The Muschelkalk (German for "shell-bearing limestone", pronounced [ˈmʊʃl̩ˌkalk] ) is a sequence of sedimentary rock strata (a lithostratigraphic unit) in the geology of central and western Europe. It has a Middle Triassic (240 to 230 million years) age and forms the middle part of the three-part Germanic Trias (that gives the Triassic its name) lying above the older Buntsandstein and below the younger Keuper. The Muschelkalk ("mussel-chalk") consists of a sequence of limestone and dolomite beds.

In the past, the time span in which the Muschelkalk was deposited could also be called "Muschelkalk". In modern stratigraphy, however, the name only applies to the layers of rock.

The Buntsandstein (German for coloured or colourful sandstone) or Bunter sandstone is a lithostratigraphic and allostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Buntsandstein predominantly consists of sandstone layers of the Lower Triassic series and is one of three characteristic Triassic units, together with the Muschelkalk and Keuper that form the Germanic Trias Supergroup.

The Buntsandstein is similar in age, facies and lithology with the Bunter of the British Isles. It is normally lying on top of the Permian Zechstein and below the Muschelkalk. In the past the name Buntsandstein was in Europe also used in a chronostratigraphic sense, as a subdivision of the Triassic system. Among reasons to abandon this use was the discovery that its base lies actually in the latest Permian.