sandstone - yellow-brown medium-grained moderately lithified Miocene sandstone - hand/display specimen

This sandstone, from the Marple Canyon Sandstone member of the Ridge Route Formation, is Miocene in age, is moderately lithified, and was deposited in a deltaic to delta plain environment. The Ridge Basin is characterized by a variety of depositional environments. A closed or semi-closed basin during the Miocene and Pliocene, it exhibits shallow fresh-water lacustrine deposits such as lagoonal and shoreline deposits and bar complexes, as well as deep fresh-water turbidites and various types of sediment gravity flows. This sandstone was deposited in a delta or deltaic plain. The field photo shows interbedded sandstone, shale and siltstone in an outcrop of the Ridge Route formation. Notice the sandstone is resistant to weathering and forms a prominent ledge. In arid areas, sandstones are cliff-formers. Below the yellow brown sandstone the shale forms a slope, with gray siltstone forming a number of small ledges below. The sand grains in these specimens, when rubbed off onto a sheet of pa