1. Geology 3120 - A structural geology primer

2. Outline Lithology Strength Deformation styles Geologic time
Stress
Lithology
Strength
Deformation styles
Geologic time
Deformation movements
Attitudes
Scaling Relationships
Examples

3. Stress
Stress = (Force / Area)
Tensile
Shear
Compressive y x

4. Lithology Most stiff Granite Dolomite Arkose Quartz Sandstone
Greywacke
Coarse grained limestone
Fine grained limestone
Siltstone
Marl, mudstone
Shale
Anhydrite
Halite
Least stiff (fluid)

5. Strength of rock Strength Depth
In addition to lithology, strength is a function of pressure, temperature, pre-existing weakness, chemical reactions, time

6. Regarding Geologic Time…
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Required knowledge: Eras, Periods
Eras - Paleozoic ( My) Mesozoic ( My) Cenozoic (65-0 My)
Periods - COSDMPP TJK TQ

7. Deformation Styles
Ductile N
Brittle

8. Deformation Movements
BEFORE
AFTER

9. Attitudes Planes Lines Faults Slickenlines and grooves Bedding
Contacts
Lines
Slickenlines and grooves
Mineral growth
Piercing points

10. Scaling Relationships
Displacement (D)
Length (L)

11. Examples
Faults
Folds
Joints
Dikes
Shear zones
Extensional veins

12. Faults
Black Mountains, Death Valley

13. Faults
Black Mountains, Death Valley

14. Folds
Carboniferous limestones beds, Grenoble, France

15. Folds
Carboniferous limestones beds, Grenoble, France

16. Joints
Joints in the Sandstone, Moab region

17. Dikes
Granite dikes, Dillon, CO

18. Dikes
Granite dikes, Dillon, CO

19. Shear zones
San Gregario fault zone, California

20. Shear zones
San Gregario fault zone, California

21. Extensional Veins
Calcite-filled veins, French Alps

22. Extensional Veins
Calcite-filled veins, French Alps