Geohydrology of the Vamoosa-Ada aquifer, east-central Oklahoma

The Vamoosa-Ada aquifer, which underlies an area of about 2,320 square miles, consists principally of the Vamoosa Formation and the overlying Ada Group of Pennsylvanian age. Rocks comprising the aquifer were deposited in a near-shore environment ranging from marine on the west to nonmarine to the east. Because of changes in depositional environments with time and from place to place, the aquifer is a complex sequence of fine to very fine grained sandstone, siltstone, shale, and conglomerate, with interbedded very thin limestone. Aggregate thicknesses of water-bearing sandstones are greatest south of the Cimarron River where they reach a maximum of 550 feet in the vicinity of Seminole. North of the Cimarron River, the average aggregate thickness of the sandstones is about 100 feet but locally it may be as much as 200 feet.