Using Layer-Cake Geology to Illustrate Structural Topographic Relationships

Abstract

College students taking Historical Geology courses often have great difficulty interpreting underlying structural relationships from the outcrop patterns shown on geologic maps. A series of cut wooden blocks is traditionally used to demonstrate the connection between various outcrop patterns and their corresponding structural configurations as well as the effect of streams and other surface features on those patterns. Such blocks are quite limited, however, in that they show only a pre-selected set of circumstances and are by necessity “after-the-fact” representations. A common layer cake, after appropriate modifications, provides a better block in that it can show the progressive development of particular outcrop patterns. A moist pound cake (or other dense, coherent cake) is prepared according to specifications and cut into smaller blocks as needed. Dipping beds, folds, faults and differential erosion can be easily and effectively demonstrated. Stream valleys can be carved into the blocks at any desired...