Geologic units in Eddy county, New Mexico

Piedmont alluvial deposits (Holocene to lower Pleistocene) at surface, covers 23 % of this area

Includes deposits of higher gradient tributaries bordering major stream valleys, alluvial veneers of the piedmont slope, and alluvial fans. May locally include uppermost Pliocene deposits.

Eolian and piedmont deposits (Holocene to middle Pleistocene) at surface, covers 17 % of this area

Interlayered eolian sands and piedmont-slope deposits along the eastern flank of the Pecos River valley, primarily between Roswell and Carlsbad. Typically capped by thin eolian deposits.

Older alluvial deposits of upland plains and piedmont areas, and calcic soils and eolian cover sediments of High Plains region (Middle to lower Pleistocene) at surface, covers 8 % of this area

Includes scattered lacustrine, playa, and alluvial deposits of the Tahoka, Double Tanks, Tule, Blanco, Blackwater Draw, and Gatuna Formations, the latter of which may be Pliocene at base; outcrops, however, are basically of Quaternary deposits.

Alluvium (Holocene to upper Pleistocene) at surface, covers 8 % of this area

Alluvium

Queen and Grayburg Formations (Guadalupian) at surface, covers 7 % of this area

Sandstone, gypsum, anhydrite, dolomite, and red mudstone.

Artesia Group (Guadalupian) at surface, covers 7 % of this area

Shelf facies forming broad south-southeast trending outcrop from Glorieta to Artesia area; includes Tansill, Yates, Seven Rivers, Queen and Grayburg Formations (Guadalupian). May locally include Moenkopi Formation (Triassic) at top.

San Andres Formation (Guadalupian and Leonardian) at surface, covers 6 % of this area

Limestone and dolomite with minor shale. Guadalupian in south, in part Leonardian to north.

Rustler Formation (Upper Permian) at surface, covers 5 % of this area

Siltstone, gypsum, sandstone, and dolomite.

Yates and Tansill Formations (Guadalupian) at surface, covers 5 % of this area

Sandstone, siltstone, limestone, dolomite, and anhydrite.

Seven Rivers Formation (Guadalupian) at surface, covers 4 % of this area

Gypsum, anhydrite, salt, dolomite, and siltstone.

Castile Formation (Upper Permian) at surface, covers 3 % of this area

Dominantly anhydrite sequence.

Salado Formation (Upper Permian) at surface, covers 3 % of this area

Evaporite sequence, dominantly halite.

Eolian deposits (Holocene to middle Pleistocene) at surface, covers 2 % of this area

Eolian deposits.

Quartermaster and Rustler Formations (Upper Permian) at surface, covers 0.6 % of this area

Quartermaster and Rustler Formations

Capitan Formation (Guadalupian) at surface, covers 0.6 % of this area

Limestone (reef facies).

Lacustrine and playa-lake deposits (Holocene) at surface, covers 0.4 % of this area

Includes associated alluvial and eolian deposits of major lake basins.

Quartermaster Formation; red sandstone and siltstone; Upper Permian (Upper Permian) at surface, covers 0.3 % of this area

Red sandstone and siltstone.

Ogallala Formation (Lower Pliocene to middle Miocene) at surface, covers 0.2 % of this area

Alluvial and eolian deposits, and petrocalcic soils of the southern High Plains. Locally includes Qoa.

Upper Chinle Group, Garita Creek through Redonda Formations, undivided (Upper Triassic) at surface, covers 0.1 % of this area

Upper Chinle Group, Garita Creek through Redonda Formations, undivided

Bell Canyon Formation (Guadalupian) at surface, covers < 0.1 % of this area

Basin facies - sandstone, limestone, and shale.

Santa Rosa Formation (Carnian) at surface, covers < 0.1 % of this area

Includes Moenkopi Formation (Middle Triassic) at base in most areas.