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 change from brittle to ductile rock, can be subject to exceptions under specific conditions. Rapid stress application can cause fracturing below the transition zone, while above the transition zone, ductile deformation is possible with pore fluids and gradual stress application.