Backreef Yates (Permian) carbonate stringers in producing wells of the Hendrick field area, Winkler County, Texas, have lithologic and environmental characteristics which are very similar to equivalent-age outcrops in the Guadalupe Mountains of New Mexico.

Extensive dolomitization of the pay zones has not destroyed the original carbonate textures which appear to reflect oscillations of intertidal to supratidal environment in a narrow, relatively sheltered lagoon of predominantly carbonate deposition. These discrete carbonate units merge basinward with the massive Capitan reef complex and interfinger shelfward with quartz sandstone.

Stylolitic algal material alternates repeatedly with calcareous mudstone pellets, aggregate grains or "lumps," pisolites, and calcarenite beach deposits. Selective leaching of pellets, aggregate grains, and pisolitic textures accounts for most of the effective porosity development. Shelfward termination of this facies and consequent termination of porosity aid in the entrapment of hydrocarbons across a low-relief anticlinal trend.

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