Apparent Dip and the Use of the Travis Apparent Dip Calculators
Apparent dip is the dip that a tabular or plane geologic feature such as a bed, a fault, or a vein appears to have on a cross-section. For any given true dip, the magnitude of the apparent dip depends on the angle at which the cross-section intersects the strike of the plane. This angle is commonly called the directional angle . If it is 90°, the apparent dip equals the true dip; if it is 0°, the apparent dip is 0° and on the cross section the plane appears to be horizontal. Consequently, on cross-sections, most dips are apparent and are greater than 0° but less than the true dips.
Conventional methods of determining apparent dip require measurement of the directional angle, followed by reference to a table or graph. The Travis Apparent Dip Calculator permits the determination of apparent dip with a single measurement that requires no further reference.