The West European stress field: new data and interpretation

Abstract

The mapped stress field of Western Europe reflects the tectonic process active there. A traverse of stress measurements from the Alps and through their northern foreland to the southern border of the Lower Rhine Embayment identifies three distinct stress sub-provinces; the Western Alps, the blocks on both flanks of the Rhinegraben, and the Rhenish Shield. The Alps have high magnitude stresses up to 35 MPa in the direction of maximum compression, here called δ 1 h . The general direction of δ 1 h is about 140°. The foreland has the same directional trend of δ 1 h with a magnitude reduced to about 2.0 MPa. Local anomalies in magnitude and direction occur along the course of the Rhinegraben which is a site of active sinistral shear. The Rhenish Shield shows an internal zonation of the stress field. The magnitudes of the stresses are low (usually negative) along the axis connecting the northern end of the Rhinegraben with the rifting of the Lower Rhine Embayment. The direction there is about 150°. On the eastern and western flanks of the shield the stress directions are essentially the same as in the southern blocks. These zones are distant from the belt of active strain release, consequently stresses of up to 4.0 MPa have accumulated.