Faults are fractures in Earth’s crust. Faults are classified as normal, reverse, or strike-slip. Normal faults occur when the end of one plate slides vertically down the end of another. Reverse faults occur when one plate slides vertically up the end of another. A strike-slip fault occurs when two plate ends slide past each other horizontally. In an oblique fault there is plate movement vertically and horizontally at the same time.