MOVEMENT OF PLATES AND FORMATION OF FOLDS AND.pptx

MOVEMENT OF PLATES AND FORMATION OF FOLDS AND.pptx

1. MOVEMENT of PLATES and FORMATION of FOLDS AND FAULTS

2. The process of changing the material that make up the rocks. It has two different types: Contact metamorphism – happens due to heat and reactive fluids Regional metamorphism – happens due to extreme pressure Metamorphism

3. Compressional – rock pressed together into itself, crust movements cause two rocks to squeeze Tension – involves forces pulling in opposite directions, which results in strain that stretches and thins rocks. Four Types of Stress

4. 3. Shear – force tending to cause deformation of material by slippage along a planes parallel to imposed stress - it is also known as rock deformation 4. Confining – deeply buried rock is pushed down by the weight of all material above it. Since the rock cannot move, it cannot deform. This is called cofining stress

5. Is the theory that Earth’s outer shell is divided into several plates that glide over the mantle, the molten rocky layer above the core. Tectonic plates interact at location called plate boundaries. PLATE TECTONICS

6. Are the edges where two plates meet. Most geologic activities including volcanoes, earthquakes, and mountain building, take place at plate boundaries. Plate boundaries is important because along these boundaries deformation of the lithosphere is happening. PLATE BOUNDARY

7. Divergent plate boundaries – two plates move away from each other. Places where plates are coming apart are called divergent boundaries. Covergent plate boundaries – two plates move towards each other. Mountains, earthquake, and volcanoes form where plates collide. Types of Plate Boundaries

8. 3 . Transform plate boundaries – two plates slip past each other. Places where plates slide past each other called transform boundaries. The sliding motion causes earthquakes.

9. One of the most common geological structures found in rocks The bend notice in rocks are called folds. Folds may occur as single local bends or may occur repeatedly and intricately folded into tectonic history of the region Fold are result are result of ductile deformation of rocks in response to external forces FOLDS

10. 1. Anticline – Layered rocks folded into arches, when the beds are bent upwards the resulting fold is called anticline. This fold is convex upward. 2. Syncline – opposite to anticline in its nature, when the beds are bent downwards the resulting fold is called syncline. This fold is convex downwards. 3. Monocline – is simple bend in the rock layers so they are no longer horizontal. TYPES OF FOLDS

11. Symmetrical folds – axial plane is vertical and bed lips at approximately the same angle but opposite in directions, either side on the plane Asymmetrical folds – axial planes are inclined and one limb of the opposite limb of the fold dips more steeply than the opposite limb FOLDS CAN BE CLASSIFIED BY THEIR GEOMETRY WITH RESPECT TO THEIR AXIALPLANE

12. 3. Overturned folds – axial plane is inclined and both limbs of the folds dip in the same direction 4. Recumbent folds – it is sideways – closing neutral structure that is neither a synformal nor an antiformal fold

13. Rocks that undergo brittle deformation tend to fracture into joints and faults JOINTS - a joint is a crack in a rock along which no appreciate movement has occurred. - can form as a result of expansion and contraction of rocks. - aid in weathering by providing channels where water and air can reach deep into the formation JOINTS AND FAULTS

14. FAULT – is a plane dislocation where rocks on one side of the fault have moved relative to rocks on the other side. - can form in response to any one of the three types of forces: compression, tension and shear - divides rock unit into two blocks : hanging wall and footwall

15. Hanging wall – block of rock above an inclined fault plane Footwall – the block of rock below an inclined fault plane

16. Normal fault – if the hanging wall slips downward relative to the footwall Strike slip fault – produced by shear forces, where one block slips horizontally past yhe other R everse fault – Compressional forces typically push the hanging wall upward relative to the footwall Oblique fault – compressional forces typically push the hanging wall upward the relative to the footwall TYPES OF FAULTS

17. This activity shows how folded and faulted rocks can provide evidence of the size and direction of the forces which produces deformation. Materials : illustration board, ¼ illustration board, different colors of clay and plastic cover Procedure: Create your own folds and deformation by using clay and place it in ¼ illustration board. Name each fold and faults. ACTIVITY