Strike is represented by a compass direction. The strike often closely parallels the contact between different rock units. Strike and dip symbols look like short T s . They are placed on the map view only. Part A. Tilted Rocks .
Tilted rocks are the simplest form of geologic structure .
By careful examination of tilted rock units we can get a good sense of how thick the rock units are, develop a general relationship between thickness and angle of dip, and also establish a general relationship between relative age and dip direction. The true thickness of a rock layer is measured perpendicular to the geologic contacts, whereas the apparent thickness of a rock unit is any other cut across the geologic contacts that is not. Because of irregular patterns of erosion, most surface exposures of tilted rocks show apparent rock unit thickness. Roll out 2 layers of rock about 1 inch thick each. Stand them on end so that they have a strike of north and a dip of 90 o .