Significant Sand and Gravel Aquifer Maps Digital Data

The aquifer polygons data file contains significant sand and gravel aquifers (glacial deposits that are a significant ground water resource) for Maine mapped at a scale of 1:24,000. The Maine Geological Survey used this data to produce Significant Sand and Gravel Aquifers Maps. Aquifer boundaries were delineated and digitized by the Maine Geological Survey from data compiled on USGS 7.5' quadrangle bases. Aquifer polygons are coded by yield expected from a properly constructed well (ATYPE = 1 10-50 gallons-per-minute; ATYPE = 2 greater than 50 gallons-per-minute; ATYPE = 3 island of non-aquifer material within an area mapped as aquifer).

Aquifer boundaries were delineated based in part on the surficial materials dataset. The Maine Geological Survey used this data to produce Surficial Materials Maps. This dataset contains point data describing the textures of surficial sediments, independent of interpretations regarding their origin, mapped at a scale of 1;24,000. Thickness of gravel, sand, silt, clay, and diamicton is shown. Data comes from auger holes, test pits, well logs, test borings, and gravel pits. Point data was compiled and digitized by the Maine Geological Survey from data compiled on USGS 7.5' quadrangle bases. The point attribute table contains information on the type of data point and, where appropriate, depth to bedrock, depth to water table, well yield, and/or material type and thickness.

Seismic line data were also used to help delineate aquifer boundaries. This dataset contains line data describing the results of 1-channel and 12-channel seismic refraction studies mapped at a scale of 1:24,000. The results include the depth to the water and depth to the bedrock.

Digital Data

User Note

The digital data may not include information from the most recently published significant aquifers and surficial materials maps. This data will be updated periodically but may be out of step briefly with published maps. The user should check the source attributes associated with the significant aquifers data (points/lines/polygons) and verify that the digital data reflects the current published map for the quadrangle. The user can view the most recently published maps or check the source for the cited open-file map in the Maps and Publications Search by searching for the open-file number (e.g. 04-93) in the publication number field.

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Last updated on June 12, 2018