5. Marshak and Mitra (1988), Ch. 4, Ex. 4. Bill Nelson is mapping a small region in westem Nevada (Figure 1). He found the contact between the Figaro Sandstone and the underlying Jarbridge Volcanics at point BM 98 (clevation 98 m). The attitude of the contact is 360, 30W. He walked 150 m due west across nearly horizontal ground and found the contact of the Figaro Sandstone with the overlying Franklin Shale. In order to cross the Franklin Shale, heavy brush forced him to run his traverse in the direction N45W (also along horizontal ground). He found the top of the Franklin Shale at the 100 m contour line. Bill then began to climb Pointop Ridge. The lowest unit on the ridge is the Rufus Springs Formation. Bill was able to traverse this formation in the direction N90W and found its top at an elevation of 330 m. He then found a convenient sheep trail that crossed the overlying Milo Formation. The bearing of the trail is S50W. Bill traveled a map distance of 150 m along this trail before finding the contact between the Milo Formation and the overlying Pointop Dolomite. The Pointop Dolomite is exposed all the way