Conservative margins are also known as transform faults. Transform faults are mainly found on the ocean floor, where they offset mid ocean ridges and enable to ocean to spread at different rates. It was through the work of John Tuzo Wilson that these faults were recognised as the connection between the ocean ridges (divergent margins) and ocean trenches (convergent margins).

At conservative margins, plates slide past each other, so that the relative movement is horizontal, and classified as either sinistral (to the left) or dextral (to the right). Lithosphere is neither created nor subducted, and whilst conservative plate margins do not result in volcanic activity, they are the sites of extensive shallow focus earthquakes, occasionally of considerable magnitude.

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