Zechsteinformatie

The Zechsteinformatie, or Zechstein Formation, is a late Permian evaporite sequence that underlies large parts of northwestern Europe, including the Netherlands, northern Germany and parts of Poland, and extends beneath the North Sea. It records the sedimentary history of the Zechstein Sea, a set of restricted basins that largely evaporated, producing thick salt and sulfate beds during a hot, arid climate.

Lithology and mineralogy are dominated by rock salt (halite), with substantial interbeds of anhydrite and gypsum. Dolostone and minor limestones occur in places, and in some intervals economically important potash salts—such as sylvite (KCl) and carnallite (KMgCl3)—are present. The sequence was deposited in repeated evaporitic cycles, leading to a multi-layered succession of chemical and carbonate rocks.

Geology and stratigraphy reflect an evaporitic marginal sea environment. Deposition occurred in Late Permian time as seawater repeatedly overflowed and evaporated in isolated basins, producing thick halite and sulfate beds. Salt tectonics later caused diapirs and thrust belts that affected regional structure and reservoir development. The Zechstein is typically overlain by younger Permian and Triassic deposits.

Distribution and size vary across the region, but the formation forms a major subsurface feature in the Netherlands and northern Germany and extends into surrounding areas of Europe. Thicknesses also vary widely, ranging from tens to hundreds of meters in many places, with thicker salt sequences in core parts of the basin.

Economic and industrial significance is high: the Zechstein hosts key salt and potash deposits. Rock salt is mined for de-icing and chemical uses, while potash-bearing intervals support fertilizer production. The evaporite rocks also influence hydrocarbon exploration by acting as seals and forming salt-related structural traps.