Chapter 27 - Anticlines and Synclines

When rocks are compressed they react by folding and faulting; all rocks have the capacity to bend before fracturing. Folds are rarely simple, symmetrical structures, rather they form a mixture of upfolds and downfolds that make it difficult to discern a general design within the field. When you map map the distribution of rock layers and analyze the topography, it is clear that a recognizable and recurrent structure does exist. The most obvious of these are upfolds known as anticlines, and downfolds known as synclines. An anticline is a fold that looks archlike, with its limbs dipping away from the axis. Conversely, a syncline is troughlike with its limbs dipping toward its axial plane. Here in this picture you can see the folding and folding, as well as a synline to the right of the shoulder (Professor Ferber’s).