Definitions for "Transform boundary"
A boundary between plates where the relative motion is horizontal. The San Andreas fault is a transform boundary between the North America plate and the Pacific plate. The Blanco fracture zone ( Figure 12 ) is a transform boundary between the Juan de Fuca and the Pacific plates.
A plate boundary where the plates slip past eachother as a the San Andreas Fault in California.
a boundary between two crustal plates formed as they slide past one another in opposite directions without converging (see Convergence) or diverging (see Divergence).