The orientation of any line, excluding the line of steepest descent, that can be drawn on a given inclined plane (that excludes vertical and horizontal surfaces). For example, the inclination of a line joining the same fault cut observed in two adjacent wells. Within image and dipmeter analysis it is sometimes necessary to present data as apparent dips relative to the borehole to allow corrections to be applied when modelling resistivity curve responses that are a part function of apparent dip.
WHITTEN, D.G. and BROOKS, J. R. V. 1972. A Dictionary of Geology, Penguin Books, Hardmondsworth, p495.
GROSHONG, R. H. Jr. 1999. 3-D Structural Geology, Springer, Berlin, p324.