RIJKERS, RICHARD, and MARK GELUK, Geological Survey of The Netherlands, Haarlem, Netherlands

ABSTRACT: A Tectogenetic Mechanism Controlling the Evolution of the Texel-IJsselmeer High (Northern Netherlands) and Adjacent Basins

Geological studies around the Texel-IJsselmeer High have been carried out for the regional subsurface mapping project of the Geological Survey of The Netherlands.

The Texel-IJsselmeer High, in the northern part of the Netherlands, is a northwest-southeast-trending structural unit, slightly tilted to the northeast. The geological evolution of the Texel-IJsselmeer High and the adjacent areas can be linked to an extensional tectonic regime during which several Jurassic basins in the Netherlands originated.

During the Late Jurassic, the southern border of the Texel-IJsselmeer High was characterized by normal faulting. Main faults are dipping southwest and are generally part of a half-graben structure. Faulting is accompanied by subsidence of the hanging wall (Jurassic basin area), while the footwall (the Texel-IJsselmeer High) is isostatically uplifted and eroded. The proposed model is based on thinning of the lower crust beneath the basins during Jurassic extension by pure shear. This mechanism is coupled locally with shear zones (simple shear) as a result of lower crustal failure. The model is supported by observations on deep regional seismics at the southern margin of the basin area.

During the Late Cretaceous/early Tertiary, transpressional intraplate stresses reactivated the structural weakness zones in the lower and upper crust in a reversed way (inversion). During this tectonic inversion the northwest-southeast-trending Texel-IJsselmeer High acted as a buffer zone perpendicular to the direction of maximum principal stress.

Paleogeographical studies and geohistory analysis support the proposed tectogenetic model of the Texel-IJsselmeer High.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.