1. . []

A contour that connects points of equal thickness. Commonly, the isopachs, or contours that make up an isopach map, display the stratigraphic thickness of a rock unit as opposed to the true vertical thickness. Isopachs are true stratigraphic thicknesses; i.e., perpendicular to bedding surfaces.

See: contourcontour intervalcontour mapformationisochorereservoirstratigraphytrue stratigraphic thicknesstrue vertical thickness