The area where rocks on opposite sides of a fault move in opposite directions is called a strike-slip fault.

Here's a breakdown:

* Fault: A fracture or zone of fractures in the Earth's crust where there has been movement.

* Strike-slip fault: A type of fault where the movement is primarily horizontal, with the blocks of rock sliding past each other.

There are two types of strike-slip faults:

* Right-lateral strike-slip fault: Looking across the fault, the block on the opposite side moves to the right.

* Left-lateral strike-slip fault: Looking across the fault, the block on the opposite side moves to the left.

Examples of strike-slip faults:

* The San Andreas Fault in California is a right-lateral strike-slip fault.

* The North Anatolian Fault in Turkey is a right-lateral strike-slip fault.

Let me know if you have any other questions!