The Type Fox Hills Formation: Stratigraphy and paleoenvironments

abundant abyssinus ammonoids association Baculites badlands basal base bentonite bivalve bluffs Bullhead lithofacies calcareous Cheyenne-Moreau divide chiefly clay clayey sand clayey silt Colgate lithofacies Corbicula Cretaceous Cucullaea Assemblage Zone Cymbophora Cymbophora-Tellina Assemblage Zone dark-gray deposits Discoscaphites distribution exposures facies fauna feet fine-grained fossiliferous concretions fossils Fox Hills Formation Fox Hills Sandstone geologic glauconitic Hell Creek Formation Highway 63 horizon indurated Irish Creek lithofacies Iron Lightning Member jarositic silt key beds Lake sand body laminated lignitic limestone concretions lithology Little Eagle lithofacies Lower Fox Hills marine Meek and Hayden miles Missouri Valley Moreau River Moreau Valley Moreau-Grand divide nicolleti Assemblage Zone occur Ophiomorpha outcrop Pierre Shale Protocardia Pteria sandstone sandy Scaphites scattered sediment sequence silty South Dakota species specimens stratigraphic Tancredia thickness thin thin-bedded Timber Lake Member Timber Lake sand Trail City Member type area type Fox Hills unit upper jarosite westward Ziebach County