THE GEOLOGY OF SPLIT ROCK FALLS

The canyon known as Split Rock Falls, located in Surry, New Hampshire has an unusual width to depth ratio for the size of the stream that flows through it. Merriam Brook is a small stream that incises a canyon roughly 50 feet deep and 250 feet wide, through bedrock that is largely granitic. The size of the stream, and granite’s known resistance to weathering and erosion make it unlikely that Split Rock Falls was created by typical stream processes. Early field efforts led to the hypothesis that the stream was exploiting cracks (joints) in the rock. Later work proved that the joints are part of an unknown fault, which may be related to a larger, un-mapped fault system (Woltner, 2017). Structural and compositional data were collected from 7 locations along a .5 mile length within the canyon. This research will provide insight towards undocumented geologic structures in southeastern New Hampshire.