Their characteristic flat topped topography was created by meltwater streams flowing on their upper surfaces long enough to smooth the irregularities. Such well sorted, coarse textured material transmits ground water very readily, so kame deposits usually are excellent aquifers. They are common both above and below the marine limit in Maine. Eskers are typically 30 to 100 feet high and 300 to 1,200 feet wide. They can usually be traced, with breaks, for many miles.
Eskers are very similar to kames with respect to composition and internal appearance.
Gravel is more abundant than sand, and there are large piles of boulders from which the finer sediment has been sluiced away. The coarse texture of esker sediment transmits ground water very readily, so eskers generally make excellent aquifers. Outwash Plains - Outwash plains generally occur above the marine limit in Maine. They are large, flat, gently sloping plains composed of sand and gravel that was carried beyond the glacier margin by meltwater streams. They commonly occupy parts of river valleys, where they stand at higher elevations than modern flood plains and river terraces.