Fault (geology) - Slip, Heave, Throw

Slip, Heave, Throw

Slip is defined as the relative movement of geological features present on either side of a fault plane, and is a displacement vector. A fault's sense of slip is defined as the relative motion of the rock on each side of the fault with respect to the other side. In measuring the horizontal or vertical separation, the throw of the fault is the vertical component of the dip separation and the heave of the fault is the horizontal component, as in "throw up and heave out".

The vector of slip can be qualitatively assessed by studying the fault bend folding, i.e., the drag folding of strata on either side of the fault; the direction and magnitude of heave and throw can be measured only by finding common intersection points on either side of the fault (called a piercing point). In practice, it is usually only possible to find the slip direction of faults, and an approximation of the heave and throw vector.