Geologists use a prescribed method of determining the attitude (or orientation in three-dimensional space) of rock layers or any other planar geological feature (e.g., metamorphic foliation, fractures, faults, and tops of tabular units like formations). The method involves measurement of strike and dip of the rock layers or planar features. Strike is defined as the compass direction, relative to north, of the line formed by the intersection of a rock layer or other planar feature with an imaginary horizontal plane. The intersection of two flat planes is a straight line, and in this instance, the line is geologic strike. According to convention, the compass direction (or bearing) of this line is always measured and referred to relative to north. A typical bearing is given, for example, as N 45° E, which is a shorthand notation for a bearing that is 45 degrees east of north...