CoachA passive margin is the edge of a continent that was formed by rifting and is no longer a plate boundary: the continent and the adjacent ocean floor belong to the same plate. The ocean–continent transition is the zone of the margin, kilometres to tens of kilometres wide, between thinned continental crust and normal oceanic crust. The break-up unconformity is the unconformity that separates the sediments deposited in the rift basins, tilted with their blocks, from the undisturbed sediments laid over the margin after break-up.
