Although the transition zone generally marks a shift from brittle rock to ductile rock, exceptions exist in certain conditions. If stress is applied rapidly, rock below the transition zone may fracture. Above the transition zone, the rock may deform ductilely if pore fluids are present and stress is applied gradually.
The transition zone, while typically signifying a shift from brittle rock to ductile rock, can be subject to exceptions under specific circumstances. Rapid stress application may cause fracturing in rock below the transition zone. Above the transition zone, ductile deformation is possible if pore fluids are present and stress is applied gradually.