The Memphis Sand of the Claiborne Group of Tertiary age underlies approximately 7,400 square miles in western Tennessee. The formation primarily consists of a thick body of veryfine to very coarse sand that includes subordinate lenses or beds of clay and silt at various horizons. The Memphis Sand ranges from 0 to about 900 feet in thickness, but where the original thickness is preserved, it is about 400 to 900 feet thick. The Memphis Sand yields water to wells in most of the area of occurrence in western Tennessee and, where saturated, makes up the Memphis aquifer.
Recharge to the Memphis aquifer is from precipitation on the outcrop, which is a broad belt across western Tennessee, or by downward infiltration of water from the overlying fluvial deposits of Tertiary(?) and Quatemary age and alluvium of Quatemary age. Long-term data from five observation wells indicate that water levels have declined at average rates rangingfrom less than 0.1 to 1.3 feet per year during the period 1928-83. The largest declines have been in the Memphis area. Water from the Memphis aquifer generally is a calcium bicarbonate type, but locally is a sodium bicarbonate or mixed type. The water contains low concentrations of most major constituents and generally is suitable for most uses. Dissolved-solids concentrations range from 19 to 333 milligrams per liter. The results from 76 aquifer tests made in the Memphis area and western Tennessee during the period 1949-62 indicate that transmissivities range from 2,700 to 53,500 feet squared per day, and storage coefficients range from 0.0001 to 0.003. The Memphis aquifer provides moderate to large quantities of water for many public and industrial water supplies in western Tennessee and small quantities to numerous domestic and farm wells. Withdrawals for public and industrial supplies in 1983 averaged about 227 million gallons per day, of which 183 million gallons per day were in the Memphis area. The Memphis aquifer has much potential for future use, particularly at places outside the Memphis area.
Additional Publication Details
USGS Numbered Series
Geology and ground-water resources of the Memphis Sand in western Tennessee
Water-Resources Investigations Report
U.S. Geological Survey ;
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