Metal mining activity has never been big in the region, but copper, zinc 

 and nickel sulfides are reported in high concentrations in the St. George 

 River basin (Bland 1957). 



The seismicity of Regions 2 and 3 is low with a risk level estimated to be 

 minor in the eastern portions to moderate in the coastal western portions 

 (NOAA, 1971). Thirty two or more earthquakes have been observed within the 

 region (Hadley and Devine, 1975). The last major earthquake in this region 

 oc cured in 1979 near Wiscasset. The magnitude of this event was estimated to 

 be 4.3 on the Richter Scale (personal communication from Walter Anderson, 

 Maine Department of Geology, Augusta, ME; 1979). 



Surficial Geology: 



Regions 2 and 3 surficial deposits differ little in their distribution 

 throughout the area. Typically, this region is dominated by thin deposits of 

 till on topographic highs with bedrock valleys filled with variable thicknesses 

 of marine deposits (Presumpscot Formation) . Region 2 differs from Region 1 

 in that end moraines, ridges of till and ice-contact stratified deposits, 

 are ubiquitous throughout the terrain. Larger ridge and ridge complexes are 

 composed mostly of stratified deposits, while smaller ridges (washboard 

 moraines) are covered with marine clay and consist primarily of compact 

 glacial till. An example of a larger moraine complex consisting of stratified 

 deposits is the moraine system running east - west in St. George and Friendship. 



The outer islands of this region are essentially bare of surficial 

 deposits, but thin tills and marine clays fill in some of the topographic 

 lows of these islands (Caswell, 1974). 



Surficial deposits are generally thin throughout the region, but range 

 up to 100 feet thick locally (Caswell 1974 and 1977) . Thick outwash deposits 

 occur in Topsham, and inland in Whitefield and Jefferson. 



The soils of Regions 2 and 3 generally consist of loamy and clayey soil 

 associations, but are locally sandy in ice-contact surficial deposits. 



Hydrogeology: 



Areas of high bedrock yield are located in Topsham, Damariscotta, 

 Wiscasset, Pemaquid and Union. Each area of high yield is associated with a high- 

 angle thrust fault or normal fault and produces yields exceeding 50 gpm 

 (Caswell 1974 and 1977). Other zones moderate of yield (Boothbay Harbor and 

 South Bristol) occur, but most bedrock wells yield less than 10 gpm. 



High iron content water is commonly associated with bedrock aquifer 

 zones and heavy use of bedrock wells along the seaward tips of peninsulas 

 (Pemaquid) produces brackish wat6r. Several bedrock wells within Regions 2 

 and 3 have yielded high salt-content water. These wells apparently tap 

 trapped marine waters which became part of the groundwater reserve during 

 times of post-glacial submergence (Caswell 1979). 



(Continued) 

 2-D-4 



