Late Permian (Zechstein) rifting in the Netherlands: models and implications for petroleum geology

Multidisciplinary studies in the Netherlands have revealed two new phases o f late Variscan extensional faulting during the Late Permian. The names Tub antian I and II are proposed in this paper. Tubantian I movements were trig gered by rapid deposition and loading of anhydrite upon a differentiated ba sement, in combination with mild E-W extension. A series of small pull-apar t basins and tilted fault blocks formed and local collapse occurred of the Variscan Front. The relief was subsequently filled with carbonates and evap orites of the Z1 (Werra) Formation. Fault movements stopped prior to deposi tion of the Z2 (Stassfurt) Formation. Tubantian II movements caused uplift and erosion, especially in the southern onshore Netherlands. Contemporaneou sly, sandy erosional products were deposited in the southwestern offshore a rea of the Netherlands and the adjacent UK sector and playa-type halites an d claystones accumulated in the central parts of the basin. Three features have implications for hydrocarbon exploration: the early formation of fault /dip closed structures shortly after deposition of the Upper Rotliegend; th e reorganization of the fluid-flow system and the deposition of contemporan eous sandy deposits.