An experimental approach to basement-controlled faulting

Abstract

To assist in the interpretation of fault structures in the North Sea, a programme of scaled-model experiments was run in a specially-built sandbox. Faults were produced in the sand overburden in response to normal displacement along faults in the underlying basement. Variations in overburden fault geometry were studied in relation to the attitude of basement faults and variations in sand properties. A stereoscopic method was used to analyse successive stages of development. In the experiments, two stages were observed. Initially, curved precursor faults formed, particularly over high-angle basement faults. These were followed by planar normal faults. Over low-angle basement faults, antithetic as well as synthetic normal faults were prominent.