Carlile Shale
Introduction The '''Carlile Shale''' is a Turonian age Upper/Late Cretaceous series shale geologic formation in the central-western United States, including in the Great Plains region of Colorado, Kansas, Nebraska, New Mexico, North Dakota, South Dakota, and Wyoming.
History of investigation The Carlile Shale was first named by Grove Karl Gilbert for exposures at Carlile Spring, located about  west of Pueblo, Colorado. He described it as a medium gray shale, capped with limestone or sandstone, and assigned it to the Benton Group. By 1931, William Walden Rubey and his coinvestigators had mapped it into Kansas and the Black Hills. Rubey also first assigned it to the Colorado Group. C.H. Dane assigned it to the Mancos Shale in New Mexico in 1948.
Description The formation is composed of marine deposits of the generally retreating phase (hemi-cycle) of the Greenhorn cycle of the Western Interior Seaway, which followed the advancing phase of the same cycle that formed the underlying Graneros Shale and Greenhorn Formation. As such, the lithology progresses from open ocean chalky shale (with thin limestones) to increasing carbonaceous shale to near-shore sandstone. Near the center of the seaway, currents in the remnant shallows sorted skeletal remains into a mass of calcareous sand. The contact between the Carlile Shale and the overlying Niobrara Formation is marked by an unconformity in much of the outcrop area, but where an unconformity is not discernible, the boundary is typically placed at the first resistant, fine-grained limestone bed at the base of the Niobrara Formation.== Gallery == == Fossil content == Upper Turonian series plesiosaur remains are among the fossils that have been recovered from the strata of its Blue Hill Shale Member in Kansas. The Carlile in eastern South Dakota contains shark teeth, fossil wood and leaves, and ammonites.===Reptiles=======Crocodyliforms==== '''Crocodyliforms''' Genus  Species  Location '''Stratigraphic position''''''Material''' Notes  Images ''Terminonaris''''T.'' cf. ''T. browni'' Russell County, Kansas.Fairport Chalk Member.A partial rostrum. A pholidosaur. ====Plesiosaurs==== '''Plesiosaurs''' Genus  Species  Location '''Stratigraphic position''''''Material''' Notes  Images''Megacephalosaurus''''M. eulerti''Near Fairport, Kansas.Fairport Chalk Member.A skull & anterior cervical material (FHSM VP-321).A pliosaurid.150 px Plesiosauria Mitchell County, Kansas.Blue Hill Member.Portions of a rib (FHSM VP-17299). May represent a large elasmosaur or pliosaur.====Squamates==== '''Squamates''' Genus  Species  Location '''Stratigraphic position''''''Material''' Notes  Images ''Coniasaurus''''C.'' cf. ''C. crassidens'' Russell County, Kansas.Fairport Chalk Member.2 incomplete vertebrae (FHSM VP-4418). A dolichosaurid.150 pxRussellosaurinaEllis County, Kansas.Middle of the Fairport Chalk Member.7 successive proximal caudal vertebrae (FHSM VP-17564).A russellosaurine mosasaur.===Fish=======Cartilaginous fish==== '''Cartilaginous fish''' Genus  Species  Location '''Stratigraphic position''''''Material''' Notes  Images''Cretodus''''C. houghtonorum''North-central Kansas.Blue Hill Shale.A partial skeleton consisting of 134 disarticulated teeth, 61 vertebrae, 23 placoid scales, and fragments of calcified cartilage.A mackerel shark. ''Cretoxyrhina''''C. mantelli'' Dixon County, Nebraska.Fairport Chalky Shale Member.A tooth (UNSM 129549). A large mackerel shark.150 px''Ptychodus''''P. latissimus''Kansas.Codell Sandstone Member.3 teeth.A ptychodontid.''P. mammillaris''North of Schoenchen, Ellis County, Kansas.Fairport Chalk Member.A medial tooth (FHSM VP-15284).A ptychodontid.150 px''P.'' sp.Ellis County, Kansas.Blue Hill Shale Member.A tooth contained in a coprolite (FHSM VP-13325).A ptychodontid.<!--
Paleofauna '''Placeholders of the Placeholder Formation''' Genus Species Location Stratigraphic position Abundance Notes Images'''' -->
See also * Volcanic mineralization of the Greenhorn cycle:** Bentonite, sedimentary volcanic ash (named for the original Graneros/Greenhorn/Carlile classification), generally showing some weathered iron stain in the Colorado Group** Pyrite, precipitation of volcanic sulfuric acid with oceanic iron as FeS2** Limonite, pyrite in limestone weathered to HFeO2 (rust stain or yellow ochre)** Selenite, CaSO4 associated with Bentonite seams and ochre* Plesiosaur stratigraphic distribution
References