AQUIFER STUDY 2: FELSIC IGNEOUS AND UNDIFFERENTIATED METASEDIMENTARY ROCKS
The study areas for
major aquifer studies 1 and 2 (MAS 1 and 2) are based on groups of lithogeochemical
units, which are classifications of bedrock units with similar mineral
composition, texture, and for some bedrock units, relative age (see lithogeochemical
data set below). The lithogeochemical groups have different water chemistry
characteristics as shown in Ayotte
and others (1999). The
study location map below shows the location of MAS 1 and MAS 2.
The 30-well network
of MAS 2 represents a group of lithogeochemical units in the NECB Study
Unit that commonly have elevated levels of radon gas and other radiochemicals.
MAS 2 is limited to areas underlain by bedrock units that are comprised
of undifferentiated, metamorphosed marine sediments and felsic igneous
The study area represents
a belt of rocks that extend from central Maine, through most of New Hampshire
except for the southeastern part, eastern Massachusetts, and most of Rhode
Island (see study location map below). The 30 wells were randomly selected
from bedrock wells within the study area boundary that are used to supply
water to homes (termed
domestic wells) (Scott,
1990). The wells were sampled during the summer and fall of 2000.