Named as the upper member of the Tanyard formation (new) of the Ellenburger group (rank raised). Name derived from the Staendebach Survey, a part of the T. H. Young ranch which includes of the type section, southern San Saba Co., TX on the Llano uplift. Shown on geologic map of parts of Blanco Co. Cross section Overlies Threadgill member (first published description) of Tanyard formation. Underlies Gorman formation (named) of Ellenburger. Consists of limestone in northeast part of Llano uplift, but dolomite predominates over limestone in southeast and west part of uplift. Contains some chert that weathers to shiny white masses, slabs or chips. Aggregated small stromatolitic bodies resembling warm castings present in upper part. Locally, upper two-thirds has zones of oolitic to oomoldic, laminar chert with parallel bands. Of Early Ordovician age.

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