This sample was collected in Williamson, Texas, near the south branch of the San Gabriel River. The fresh surface of the hand sample is light gray in color and the exposed, weathered surface is a brownish gray. There are little to no visible grains present. Under the microscope, as you will see in thin section, there are however, fine grains of quartz to be classified as silt. Also in the specimen there are small holes, which are probably borings of some sort.
Thin section reveals the presence of pelloids and a micritic matrix.
Under the Folk classification system, this is called a silty pelmicrite. The likely depostitional environment is deep ramp. Evidence for this is provided with the following slides. Josh Peters, Sophomore at The College of Wooster. Josh is from Mansfield, Ohio.