Late Cretaceous–Cenozoic fracturing in Lofoten, North Norway: Tectonic significance, fracture mechanisms and controlling factors

摘要: Abstract The Lofoten Ridge is a fault-controlled basement horst residing between Mesozoic basins on the North Norwegian passive margin. This major and adjacent offshore basin-bounding normal faults formed during stages of rifting from Permian–Jurassic to Early Cenozoic. Well-exposed, heterogeneous NW–SE striking brittle fracture sets have been studied onshore at Moskenes in western islands. area provides an excellent frame for understanding onshore–offshore fault–fracture correlations margin evolution as inferred high-quality seismic data. exhibit geometric kinematic variability, i.e. systematic bisecting (conjugate) fractures, parallel extensional anastomosing relay/stepping (shear) fractures. An incremental oriented σ1 compressive stress axis NE–SW σ3 was attitudes conjugate sets. different are interpreted isolation and/or progression through time, precursory (Mode I) or fractures II) more complex shear III) due varying boundary conditions controlling factors, not by mechanical weaknesses host rock. Whether parallel, conjugate, depended initial spacing timing development complementary evolving strain-stress conditions. In terms Atlantic field, trend roughly Late Cretaceous–Early Cenozoic regional extension directions but oblique that Permian–Jurassic. A switch direction WNW–ESE NNW–SSE Cretaceous, may initiated multiple reactivations and, e.g. right-lateral shearing along ENE–WSW master faults, producing block-internal Lofoten. Alternatively, reactivation transfer fault zones NNE–SSW right-stepping faults. third possibility origin ridge push forces, creating neotectonic substitute inversion structures arc-shaped domes Mid-Norwegian farther south.