Named for Sand Hills Coulee in Cheney-Palouse Scabland Tract of the Channeled Scabland, Adams Co., southeastern WA. Type locality is a composite of six roadcuts recognized across 100 km transect here called "type transect". Strata previously assigned to [late Pleistocene] Palouse loess (informal). Described as weakly developed buried soil with an abundance of prominent fine- and medium-sized filaments of carbonate. Carbonate crystals often large enough to be seen with hand lens. Calcic horizon has weak prismatic or blocky structure and <10% cemented cylindrical nodules at most sites. Maximum thickness is 1 m at KP-1 roadcut of "type transect". Lower boundary is defined by late Pleistocene (13,000 yrs B.P.) Mount St. Helens set S tephra and by upper boundary of cambic horizon of unconformably underlying late Pleistocene Washtucna Soil (new). Unconformably underlies Holocene surface soil or Holocene[?] first buried soil. Age is latest Pleistocene to middle(?) Holocene. Postdates late Wisconsinan Scabland cataclysmic flooding and may have ceased forming by about middle Holocene. Age of Mount St. Helens set S eruptive sequence determined by Crandell and others (1981); and Mullineaux (1986). Set S tephra found stratified within uppermost late Wisconsinan slackwater sediments which contributed to loess in which Sand Hills Coulee Soil formed (Baker and Bunker, 1985). Report includes stratigraphic column and correlation chart.

Source: GNU records (USGS DDS-6; Menlo GNULEX).