Penobscot Bay Geological Map
Preliminary Geological Map of Maine, showing soil and rock types. Note especially the avacado green line that extends from Thomaston almost to Camden; that is limestone. Also, the pink with red flecks on the map shows where there is granite. Note the granite from St. George, across Penobscot Bay to the southern part of Vinalhaven, on to the Stonington area. Also, there are significant granite resources in northern Penobscot Bay, where there were quarries in the Mt. Waldo area of Frankfort.
Preliminary Geological Map of Maine, compiled and edited under the direction of Robert G. Doyle, State Geologist, and published by the Maine Geological Survey, 1967.