The role of strike-slip tectonics in the Leinetal Graben, Lower Saxony

A detailed examination and interpretation of outcrop data in the northern part of the Leinetal Graben in Lower Saxony, Germany, suggests the graben is dissected and partly-bound by faults with a strong strike-slip history. We envisage a two-part tectonic evolution, which began in the Late Cretaceous to Early Cenozoic, with approximately N-S compression, which caused east-west extension (the bounding normal faults of the Leinetal Graben) and dextral strike-slip movement on the Ahlsburg Lineament. We postulate that the Ahlsburg Lineament was originally a relay ramp that developed in the early stages of the graben history. Later the major stress axes rotated anticlockwise, so that the maximum horizontal stress was oriented NW-SE. Because of this, the graben-bounding faults and the Ahlsburg Lineament were then subject to inversion under sinistral transpression, while new E-W striking dextral strike-slip faults were also initiated.