Slickensides

Geology has some funny names to it. One way to recognize a fault is sometimes an outcrop will be exposed on the fault scarp. (The fault scarp is the visual slip on the fault.) When there is a break across a rock unit, the rocks will slide along each other. With the intense forces, this will often make the slip surfaces on the rock very smooth with charateristic grooves. These smooth surfaces are what we call slickensides. Sounds almost like a water park. The grooves are called slickenlines. As part of our research in Santaquin, Utah, we came across many outcrops that contained these slickensides. We measured their orientation and plotted them on a graph that plots 3D planes on 2D paper, called a stereonet. The interesting thing about these little faults in the Santaquin Metamorphic complex, is that they were all dipping (or slanting downward) to the east, when the Wasatch fault dips to the west. Apparently these little faults did not occur at the same time as the Wasatch Fault era.