Introduction. A transform boundary is a fault zone where two plates slide past each other horizontally. Most transform faults are found in the ocean where they offset spreading ridges creating a zigzag pattern between the plates.Some transform faults occur on land.an Andreas Fault. The San Andreas Fault is the transform boundary between the North American Plate and the Pacific Plate. During the 1906 San Francisco earthquake the northern section of the San Andreas Fault slipped northward along the fault from San Juan Bautista to Cape Mendocino, a total of 296 miles (477km).