A new model for the growth of normal faults developed above pre-existing structures

Abstract Constraining the mechanisms of normal fault growth is essential for understanding extensional tectonics. Fault kinematics remain debated, mainly because very earliest phase deformation through recent syn-kinematic deposits rarely documented. To understand how underlying structures influence surface faulting, we examined in a 10 ka magmatically resurfaced region Krafla fissure swarm, Iceland. We used high-resolution (0.5 m) digital elevation model derived from airborne lidar to measure 775 profiles with lengths ranging 0.015 2 km. For each fault, measured ratio maximum vertical displacement length (Dmax/L) and any nondisplaced portions fault. observe that many shorter faults (<200 retain fissure-like features, no substantial parts their profiles. Typically, longer (>200 are vertically displaced along most have Dmax/L at upper end global population comparable lengths. hypothesize initiate as fractures material result flexural stresses caused by displacements on faults. Faults then accrue following constant-length model, grow dip strike linkage or lengthening when they reach bell-shaped displacement-length profile. This hybrid mechanism repeated deposition subsequent layer, resulting remarkably wide distribution Dmax/L. Our results capture specific early period slip-deposition cycle volcanic setting may be applicable sedimentary basins.