Depth of active solution by ground‐waters in the Pecos Valley, New Mexico

The Pecos River Drainage‐Basin is underlain by a thick series of Permian rocks consisting largely of limestone, gypsum (or anhydrite), and halite. The beds have a regional eastward or southeastward dip of 40 to 80 feet to the mile and successively younger beds are exposed at the surface from west to east across the Basin (Fig, 1). The beds of the San Andres formation and the Chalk Bluff formation or its equivalents crop out over most of the broad western part of the Basin (Fig. 1). Most of the eastern part of the Basin is immediately underlain by the redbeds was sandstone of the Dockum group, of Triassic age, which, south of Acme, are separated from the Chalk Bluff formation by the Salado and Rustler formations. North of Acme the Dockum group overlaps successively older formations ana northwest of Santa Rosa it rests upon beds in the lower part of the San Andres formation.