The Eskridge Shale or Eskridge Formation is an Early Permian geologic formation in Kansas. Its outcrop runs north–south through Kansas, extending into Oklahoma and Nebraska.[1] While named a shale, it features extensive, spectacular red and green stacked palosol mudstones, these mudstones showing prominent vertical tubular carbonate concretions, possibly from roots or vertebrate burrows.[2]

Eskridge Shale
Stratigraphic range:
Early Permian
Fresh excavation of Eskridge Shale (green and red mudstone band and gray marine shale) above the Neva Limestone and below the Cottonwood Limestone, Stag Hill roadcut of K-18 southwest of Manhattan, Kansas, 2013.
Rain-washed vertical paleosol concretions (roots or burrows), lowest 10 feet (3 meters) of the formation, 2016 excavation at Anderson and Scenic Drive, Manhattan, Kansas.
TypeFormation
Unit ofCouncil Grove Group[1]
Lithology
Primarymudstone paleosol
Othermarine shale
Location
RegionKansas, Oklahoma, Nebraska
CountryUnited States
Type section
Named forEskridge, Kansas[1]

See also

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References

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  1. ^ a b c "Geologic Unit: Eskridge". National Geologic Database. Geolex — Unit Summary. United States Geological Survey. Retrieved 2020-12-24.
  2. ^ Keith Miller, Geology of the Kansas Flint Hills: Ancient Ice Ages, Sea Levels, and Climate Change, retrieved 2021-11-28, The lower paleosol interval of the Eskridge is characterized by the spectacular development of stacked horizons of elongated carbonate nodules (Fig. 23) These are locally tightly packed and take on the appearance of a prismatic ped structure. The carbonate precipitation was likely controlled primarily by roots (ie. the nodules represent rhizocretions), but the influence of burrowing cannot be discounted (Fig. 24). Lungfish and other vertebrate burrows have been recognized at other localities within the lower Eskridge. The thin limestone beds that overly this paleosol interval are characterized by a molluskan fauna dominated by pectinid and myalinid bivalves.