Rock Deformation

Rock Deformation

1. Folds

   • Antiforms - V-shaped fold pointing upwards. Oldest rock in the centre. Limbs dip away from the centre
   • Synforms - V-Shaped fold pointing downwards. Youngest rock in the centre. Limbs dip towards the centre

2. Unconformity

   • An unconformity is a buried eroded former land surface
   • How can they be recognised?
     • Fossil Content either side indidcates different time periods
     • Large time gap in rock age (Hiatus)
     • Underlying rocks are usually deformed

3. Faults

   • Types of Fault. Normal Fault - Hanging wall is downthrown. Reverse Fault - Footwall is downthrown. Strike Slip- Two blocks moving past each other
   • HANGING WALL - Block of rock ABOVE the fault. FOOT WALL - Block of rock BELOW the fault. DIP SLIP - Movement parallel to the dip. STRIKE SLIP - Movement paralel to the Strike. HEAVE - Total horizontal displacement. THROW - Total vertical displacement

4. Morphology

   • Dip - Angle and Direction of inclination of rock strata. Strike- Directions perpendicular (at 90 degrees) to the strike
   • Limb-The area between peaks and troughs of a fold. Axial Plane - Line which disects the fold exactly in half. Hinge zone - Area of most deformation.
   • Fold Morphologies

Images and files in the map