Map 1. The Palmer Hill Delta is located near the southeast corner of the East Pittston quadrangle and overlaps into the neighboring Wiscasset quadrangle. The colors and letter symbols on this map differentiate the sediments formed in various glacial environments. Map unit Pmdph is the Palmer Hill delta, which formed when the glacier margin (hachured line) lay against Palmer Hill to the northeast and an unnamed hill to the southwest. Subglacial meltwater carved an ice tunnel in the gap between the hills, and the water rushing through this tunnel supplied the sediments that built the delta. The tunnel eventually became clogged with gravel, producing a long ridge called an "esker" (map unit Pge) that was revealed when the surrounding ice melted. Other map units shown are the Presumpscot Formation (Pp) and till (Pt). The black triangle marks the survey site where former sea level was determined to be at a present elevation of 288 feet. Short arrows indicate glacial striation localities and the azimuth (in degrees) of the ice flow direction at each site. The k label shows locations of depressions (kettles) that resulted from melting of glacial ice remnants.
Last updated on January 5, 2011