siltstone - teaching student specimens of tan siltstone from the Round Mountain unit of the Temblor Formation - UNIT OF 5 SPECIMENS

The Round Mountain Silt is famous for the now-national-landmark Sharktooth Hill fossil collecting locality. Siltstone fits between shale and sandstone in a classification of sedimentary rocks by grain size. Siltstones have a range of grain sizes as well, with this one being close to the finer-grained end of the siltstone spectrum. Compare it with the larger-grained siltstone from the Ridge Basin Group that we offer.  The farther a sediment is transported, the smaller and rounder its grains become. Finer grained sediments take longer to settle out of the water column and are deposited farther from a shoreline in deeper water. This siltstone is marine and some specimens are fossiliferous with small clams. Their delicate shells confirm that this is a deep water sediment, as the shells are too fragile to withstand the high energy near-shore environment.  These siltstone was collected from outcrops along the south edge of the floodplain of the Kern River in Kern County, California. T