Middle North Sea Group

Groups, formations, members and layers after NITG-TNO
Marine
Veldhoven Formation VE Someren Member VESO
Voort Member VEVO
Wintelre Member VEWI
Rupel Formation RU Bilzen Member RUBI Berg Member RUBIBE
Kerniel Member RUBIKE
Kleine Spouwen Member RUBIKS
Boom Member RUBO Brinkheurne Member RUBOBR
Winterswijk Member RUBOWI
Eigenbilzen Member RUEB
Ratum Member RURA Ootmarsum Member RURAOO
Tongeren Formation TO Goudsberg Member TOGO
Klimmen Member TOKL
Zelzate Member TOZE Bassevelde Member TOZEBA
Ruisbroek Member TOZERU
Watervliet Member TOZEWA

The Middle North Sea Group (abbreviation: NM) is a group of geologic formations in the Dutch subsurface, part of the North Sea Supergroup. The three formations of this group form a thick sequence of sediments in the Dutch subsurface, they crop out in parts of the southern Netherlands. The Middle North Sea Group was deposited from the late Eocene to late Oligocene, between 37 and 23 million years ago.

Its three formations are (from old to young) the Tongeren, Rupel and Veldhoven Formations. The Tongeren Formation has a continental to paralic facies, the other two consist mainly of shallow marine clays and sands.