Oceanic fracture zones (FZ�s)
Rectilinear (straight), often for 1000�s of km across ocean basin
Narrow, usually <100 km and may be <10 km wide
Vertical relief across a FZ may be several km
Axial valleys offest as much as 1000�s of km across FZ�s
When FZ�s extend into abyssal plains, they are usually covered sedimentary rock