1. DATING ROCK LAYERS RELATIVE DATING
Law of Original Horizontality
Law of Superposition
Extrusions
Intrusions
Index Fossils

2. ROCK LAYER DISTURBANCES FAULTS

3. Hanging Wall and Foot Wall
A = Hanging wall B = Foot wall

4. Disturbances to rock layers Faults: Dip slip, Strike Slip and Oblique
DIP SLIP FAULTS
Normal Fault
In a normal fault, the block above the fault moves down relative to the block below the fault. This fault motion is caused by tensional forces and results in extension. [Other names: normal-slip fault, tensional fault or gravity fault] EX., Sierra Nevada/Owens Valley; Basin & Range faults

5. Dip Slip Fault Reverse Fault
In a reverse fault, the block above the fault moves up relative to the block below the fault. This fault motion is caused by compressional forces and results in shortening. A reverse fault is called a thrust fault if the dip of the fault plane is small. [Other names: thrust fault, reverse-slip fault or compressional fault] EX., Rocky Mountains, Himalayas

6. STRIKE SLIP FAULTS Strike Slip
In a strike-slip fault, the movement of blocks along a fault is horizontal. If the block on the far side of the fault moves to the left, as shown in this animation, the fault is called left-lateral. If the block on the far side moves to the right, the fault is called right-lateral. The fault motion of a strike-slip fault is caused by shearing forces. Examples: San Andreas Fault, California; Anatolian Fault, Turkey [Other names: transcurrent fault, lateral fault, tear fault or wrench fault.]

7. Transform Fault
A transform fault is a type of strike-slip fault wherein the relative horizontal slip is accommodating the movement between two ocean ridges or other tectonic boundaries

8. Oblique Fault
Oblique-slip faulting suggests both dip-slip faulting and strike-slip faulting. It is caused by a combination of shearing and tension or compressional forces. Nearly all faults will have some component of both dip-slip (normal or reverse) and strike-slip, so defining a fault as oblique requires both dip and strike components to be measurable and significant.

9. FOLDING MONOCLINE FOLD
The simplest type of fold is called a monocline This fold involves a slight bend in otherwise parallel layers of rock.

10. Anticline Fold
An anticline is a convex up fold in rock that resembles an arch-like structure with the rock beds (or limbs) dipping way from the center of the structure.

11. SYNCLINE FOLD
A syncline is a fold where the rock layers are warped downward (Figure 4 and 5). Both anticlines and synclines are the result of compressional stress.

12. Folding
Relative Age

13. Disturbances
Tilting - Geologic tilting, also known as tectonic tilting, occurs when the earth’s surface layers begin to tilt or slant irregularly.

14. UNCONFORMITY – A SURFACE THAT REPRESENTS A MISSING PART OF THE GEOLOGIC COLUMN
ANGULAR UNCONFORMITY – found between horizontal layers of sedimentary rock and layers of rock that had been tilted or folded

15. UNCONFORMITY – A SURFACE THAT REPRESENTS A MISSING PART OF THE GEOLOGIC COLUMN
Disconformity is an erosion surface between two packages of sediment, but the lower package of sediments was not tilted prior to deposition of the upper sediment package. Part of a sequence of parallel rock is missing ( represented by the black line)

16. UNCONFORMITY – A SURFACE THAT REPRESENTS A MISSING PART OF THE GEOLOGIC COLUMN
NONCONFORMITY - are unconformities that separate igneous or metamorphic rocks from overlying horizontal layers of sedimentary rocks. They usually indicate that a long period of erosion occurred creating an eroded surface prior to deposition of the sediments (several km of erosion necessary).  In the diagram at left, the igneous/metamorphic rocks below the nonconformity are colored in red.

17. STRATIGRAPHY
Stratigraphy refers to geological and archaeological layers that make up an archaeological deposit. Archaeologists use stratigraphy to better understand the processes that created the site.

18. STRATIGRAPHY
EXAMPLES