Permian
bookPart
The Permian System in the Netherlands is subdivided into the Lower Rotliegend, Upper Rotliegend and Zechstein groups. These groups were deposited in a large epicontinental basin extending from the UK to Poland. The Lower Rotliegend Group, deposited during the early Permian, unconformably overlays older strata (at the Base Permian Unconformity), is composed of volcanics and volcaniclastics and is only preserved locally in the Netherlands. After a significant erosional phase (Saalian Unconformity), the middle to upper Permian Upper Rotliegend sediments were deposited under warm and arid climatic conditions and are preserved in a large part of the Dutch sector. A broad southern and a much smaller northern lake edge depositional system composed of fluvial, eolian and playa-lake deposits are represented in the Netherlands. These systems are separated by the E-W oriented Silver Pit Lake in which clays and evaporites of the Silverpit Formation accumulated. With increasingly dry conditions, rapid marine floodings of the basin were accompanied by decreasing clastic input and thick evaporites and marginal carbonates, known as the Zechstein Group accumulated in the Netherlands and neighbouring regions. The thick layer of Zechstein rock salt is deformed into many salt bodies, sometimes localized along pre-existing faults, which often played a key role in Dutch diapirism and strongly influenced the post-Permian structural development. The depositional thickness of the Permian reaches almost 2000 m in the northern offshore. The Upper Rotliegend Group contains more than 95% of the natural gas resources in the Netherlands and it is a target for geothermal projects and CO2 storage. The Zechstein Group contains exploitable rock salt and potassium-magnesium salts.
Topics
TNO Identifier
1013569
Publisher
Amerstdam University Press
Source title
Geology of the Netherlands
Pages
127-153