Map of surface materials reproduced from Appendix 1 on page 159 of “Exploring Stone Walls.”
Samples of stones from different map units shown below.
Map unit “Sand & Gravel” (ORANGE) consists of stones rounded by subglacial milling and meltwater transport. Hope Ontario.Map unit “Moraines” (BLACK) consists of a great variety of material, generally a containing a mixture of stone shapes and sizes. Montauk Point, Long Island.Map unit “Fines” (PINK) consist of clay-, silt- and sand-rich lake and marine sediments without surface stones. They are present at great depth.Map unit “Shallow Bedrock” (BLUE) is usually ledge overlain by rubble or hardpan. Bethel, ME.
