Goal: The purpose of this lab is to learn how to locate yourself on a topographic map, to recognize the nature of faulting in an area and to do a simple stress analysis with the data collected.
1) You are given a blown-up topographic map of the field area. Note the scale and direction of North. First, locate yourself on the topographic map using the curved stream channel as a reference. Next, make a geologic map of the study area showing the position of the major rock contact and positions of prominent faults. Measure the orientation (strike and dip) of and discuss the sense of slip on the large antithetic fault. (30 points)
2) The TA will walk around the large limestone outcrop with you and show you a number of secondary faults. Note the variable orientations of and evidence for slip directions on these faults. Measure the strike and dip of two secondary faults and the trend and plunge of the grooves or striae on those fault surfaces. Plot the data on a stereonet (one stereonet per fault). Plot the orientations of the principal stresses (s1, s2, s3) for each fault on your stereonets assuming Coulomb faulting theory. (20 points)
3) Measure two bedding orientations: one on both the footwall side of the large antithetic fault, one on the hangingwall side. **Note the lateral distance between the two measurements.** (10 points)
4) Define apparent and net fault slip. Discuss how the large antithetic fault might have formed noting it's orientation with respect to the Wasatch Fault. (10 points)
5) Calculate the net slip on the large antithetic fault at the mouth of the gulch using the measured dip of the fault, the two bedding dips measured in (3) and assuming that the movement along the fault is purely normal (no strike-slip movement). (20 points)
6) Prepare a report discussing the methods used in the lab and the results. Be sure to answer ALL questions asked. (10 points)