Snow Sandwiched Shale
Drifts of snow sandwich an outcrop of Hennessey shale (known in its Texas exposures as Clear Fork shale) -- a Permian redbed formation responsible for the bright red, nutrient-poor soils of much of central Oklahoma. The shale is high in clay content. In hot dry weather, its soils contract and crack, sometimes causing foundation damage. Shale is a soft rock that splits easily on horizontal bedding planes; and weather extremes hasten the erosion.
Norman, OK (31 Dec 0), looking SSW
(GPS)
