Explain how slickensides are used to determine the slip orientation of the fault plane?

Slickensides are smooth, striated surfaces found on fault planes that form due to the movement of rocks during faulting. By examining the orientation and direction of these striations, geologists can determine the slip direction of the fault, which indicates how the rocks have moved relative to each other. The angle and pattern of the striations can also provide insights into the type of fault (e.g., normal, reverse, or strike-slip) and the stress regime involved. Analyzing slickensides thus allows for better understanding of the kinematics of fault movement.