Transform Plate Boundaries

In the dry, central region of California, the San Andreas Fault visibly separates two massive tectonic plates. On one side lies the Pacific Plate, and on the other is the North American Plate.

Scientists once thought the San Andreas Fault was just a crack in the Earth's crust, but later identified it as a transform plate boundary.

Transform boundaries form when two tectonic plates slide past each other horizontally, grinding against each other as they move in opposite directions. This grinding movement often leads to powerful earthquakes.

Unlike other types of plate boundaries, transform boundaries do not create the conditions needed to form igneous, sedimentary, or metamorphic rocks.

Transform boundaries are not only found on land but also under the ocean along mid-ocean ridges. Underwater transform faults are typically much smaller than those found on land.

The Alpine Fault is another example of a transform boundary, which stretches over 310 miles along the boundary between the Australian and Pacific plates in New Zealand’s South Island, linking the Puysegur trench to the Marlborough Fault system.