Fault reactivation and propagation in the northern Adamello pluton: The structure and kinematics of a kilometre-scale seismogenic source

摘要: Abstract The northern Adamello batholith (European Southern Alps) is crosscut by E-W trending pseudotachylyte-bearing paleoseismic fault zones composed of multiple subparallel strands. main faults are the Gole Strette Fault Zone (GSFZ), here discussed in detail, and Larghe (GLFZ). western ending GSFZ intersects propagation Gallinera Thrust, a regional structure Late Cretaceous age, which was truncated dismembered late Eocene - early Oligocene emplacement batholith. slip analysis paleostress reconstruction suggest that Thrust were both active during dextral transpression related with orogen-parallel shearing along Periadriatic System. remnants within reactivated as dextral-reverse do not include pseudotachylytes. shows changing structural features from west to east: dip angle decreases 80° 45°, vector passes strike-slip (pitch 20°) oblique 35° 45°), zone thickness increases (> 800 m at intersection GLFZ). an immature strong indicated (i) local geometry controlled precursor joints; (ii) along-strike segmentation; (iii) spread seismogenic into wide zones.