Easy Solutions to Stereonet Rotation Problems: GEOLOGIC NOTES

Abstract

This note describes methods for solving problems on stereonets. The methods described are based on the concept of rotating a plane on the surface of a stereographic reference sphere, thereby generating easily visualized cones of rotation that can be readily portrayed on stereonets. Because half-tangent methods avoid the confusing necessity of converting planes to poles and poles back to planes, their results are both faster and less prone to error than conventional pole plot methods. Half-tangent methods apply to problems of any kind, but are especially convenient for determining both the cone of core dips and the dipmeter cone of silence associated with deviated wells.