Slump along Highway 16 about 1 mile south of center of Chamberlain. The lower part of the slump, with a pressure ridge caused by forward and upward thrusting of the slump block at the toe, is inferred to be the original slump block. The upper part formed a graben formed by collapse after the original slump block moved and left the upslope material unsupported. Brule County, South Dakota. October 14, 1954. Figure 6 in U.S. Geological Survey. Professional paper 675. 1973. Professional Paper-0675

Digital File:ecf00003

ID. Erskine, C.F. 3