Eskridge Shale | |
---|---|
Stratigraphic range: Early Permian | |
Type | Formation |
Unit of | Council Grove Group[1] |
Lithology | |
Primary | mudstone paleosol |
Other | marine shale |
Location | |
Region | Kansas, Oklahoma, Nebraska |
Country | United States |
Type section | |
Named for | Eskridge, Kansas[1] |
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]
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.