Deformation of Crust

1. Deformation of Crust By Spenser Bryant, Paige Johnson, Dakota Brown, Lauren Johnston S.1 2011

2. DefinitionsSection One • Deformation:Bending, tilting, breaking ofcrust • Isostasy: equilibrium between lithosphere/athenosphere • Stress: amount of force on an area • Strain: Change rocks by shape/volume • Fold: Ductile strain; rock layers bend • Fault: Break in body of rock

3. What is…? • Compression: Squeezes and shortens • Tension: Stretches and pulls • Shear Stress: Distorts in opposite directions • Fracture: Break along rock that doesn’t move • Fault Plane: Surface along which motion occurs • Hanging Wall: Rock above fault plane

4. What is…? Cont. • Foot Wall: Rock below fault plane • Normal Fault: Hanging wall moves down • Reverse Fault: hanging wall moves up • Thrust Fault: Reverse, but low angled • Strike-Slip: Rock slides horizontally

5. Anatomy/Types of Folds • Limbs: Sloping sides of the fold • Hinge: Where the limbs meet • Overturned: Lying on side • Anticline: Oldest layer in center • Syncline: Youngest in center • Monocline: Limbs are horizontal

6. Questions • 1.) Difference between fold/fault? A.) Fault: Break; Fold: Bend B.) Fault: Bend; Fold: Break C.) Fault: Rat; Fold: Hippopotamus 2.) Definition of strain: A.) Pulled muscle B.) Bending, tilting, breaking of crust C.) Change rocks by shape/volume • 3.) Definition of Deformation A. When two tectonic plates shift B. Bending, tilting, breaking of crust C. Magma turns to lava 4.) What is Isotasy? A. A balance between the Sun and Moon B. equilibrium between lithosphere/athenosphere C. An Elephant balancing on a ball

7. Questions cont. 5.) How many faults are there? A.) 3 B.) 4 C.) 5 6.) Difference between anticline/syncline? A.) Anticline: Old center; Syncline: Young B.) Anticline: Young center; Syncline: Old center 7.) Difference between Normal/Reverse faults? A.) Normal: H-wall up; Reverse: H-wall down B.) Opposite A.) 8.) What are Strike-Slip faults? A.) Rock slides then pushes up B.) Rock slides then slips down C.) Rock slides horizontally

8. Answers • 1.) A • 2.) C • 3.) B • 4.) B • 5.) B • 6.) A • 7.) B • 8.) C

9. Section 2: Definitions • Mountain Range: Grouping of adjacent mountains • Folded: Tectonic movements push together; Accordion • Fault-Block: Faults break Earths crust; some drop • Dome: Circular structure that slope

10. What is…? • Mountain System: Groups of adjacent mountains • Mountain Belts: Two large systems; Eurasian-Melanesian/Circum-Pacific • Collisions: Continental-Oceanic- Oceanic subducts Oceanic-Oceanic- Denser subducts Continental-Continental- Denser subducts

11. What is…? Cont. • Plateau: Large flat areas above sea-level • Grabens: Long and narrow valleys • Volcanic Mountains: Formed when magma reaches surface • Hot Spots: Volcanic areas far from tectonic activity

12. Questions 1.) Definition of Mountain Range? A.) Grouping of adjacent mountains B.) Mountains surrounding a plain C.) A range on a mountain 2.) Difference between Folded/Fault-Block? A.) Fold: pull apart; Fault-Block: slide B.) Fold: slide; Fault-Block: pull apart C.) Fold: pushed; Fault-Block: sides drop 3.) What is a dome mountain? A.) A mountain in the shape of a dome. B.) A plate shift C.) The Palomar Observatory 4.) When Oceanic/Continental plates collide…? A.) Oceanic subducts B.) Continental subducts

13. Questions… Cont. 5.) What is a plateau? A.) A rocky domed area B.) Sandy mountain C.) Flat topped figure above sea level

14. Answers • 1.) A • 2.) C • 3.) A • 4.) A • 5.) C