Geologic units in Harding county, New Mexico

Ogallala Formation (Lower Pliocene to middle Miocene) at surface, covers 31 % of this area

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

Upper and lower Cretaceous rocks of east-central and northeast New Mexico (Cenomanian and Albian) at surface, covers 13 % of this area

Consists of Dakota Group, which includes Romeroville Sandstone (Cenomanian), Pajarito Shale, and Mesa Rica Sandstone (Albian); the underlying Tucumcari Shale (Albian) in Tucumcari area and Glencairn Formation (Albian) in Union County.

Alluvium (Holocene to upper Pleistocene) at surface, covers 12 % of this area

Alluvium

Entrada Sandstone (Middle Jurassic) at surface, covers 9 % of this area

Entrada Sandstone

Eolian deposits (Holocene to middle Pleistocene) at surface, covers 8 % of this area

Eolian deposits.

Morrison Formation and upper San Rafael Group (lowermost Cretaceous? - upper Jurassic) at surface, covers 8 % of this area

Morrison Formation and upper San Rafael Group

Bull Canyon Formation (Norian) at surface, covers 5 % of this area

Bull Canyon Formation

Upper Chinle Group, Garita Creek through Redonda Formations, undivided (Upper Triassic) at surface, covers 2 % of this area

Upper Chinle Group, Garita Creek through Redonda Formations, undivided

Basaltic to andesitic lava flows (Pliocene) at surface, covers 2 % of this area

Includes minor vent deposits and small shield volcanoes. Flows are commonly interbedded in the Santa Fe and Gila Groups.

Upper and Middle Jurassic rocks, undivided (Upper and Middle Jurassic) at surface, covers 2 % of this area

In southwest includes the basalt-bearing Broken Jug Formation.

Greenhorn Formation (Turonian to Cenomanian) at surface, covers 2 % of this area

Limited to northeastern area; the upper member (Bridge Creek Limestone) can be traced into western area where it is commonly shown as a bed-rank unit in Mancos Shale on detailed maps.

Graneros Shale (Cenomanian) at surface, covers 1 % of this area

Limited to northeastern area.

Chinle Group (Upper to middle Triassic) at surface, covers 1.0 % of this area

Map unit includes Moenkopi Formation (Middle Triassic) at base in many areas; in eastern part of state the following five formations are mapped: TRr, TRb, TRt, TRg, and TRs.

Basaltic to andesitic lava flows (Neogene) at surface, covers 0.9 % of this area

Includes minor vent deposits. Flows are commonly interbedded in the Santa Fe and Gila Groups.

Redonda Formation (Upper Triassic) at surface, covers 0.5 % of this area

Redonda Formation

Carlile Shale (Turonian) at surface, covers 0.3 % of this area

Limited to northeastern area.

Landslide deposits and colluvium (Holocene to Pleistocene) at surface, covers 0.2 % of this area

Landslide deposits on western flanks of Socorro Mountains not shown for clarity.

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 < 0.1 % 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.

Lacustrine and playa-lake deposits (Holocene) at surface, covers < 0.1 % of this area

Includes associated alluvial and eolian deposits of major lake basins.

Morrison Formation (Upper Jurassic) at surface, covers < 0.1 % of this area

Upper Jurassic nonmarine rocks.

Greenhorn Formation and Graneros Shale (Turonian and Cenomanian) at surface, covers < 0.1 % of this area

Limited to northeastern area.