First used as formation in vicinity of Austin, Travis Co, TX in Ouachita tectonic belt province. Name credited to Durham and Roux (unpublished manuscript); derivation of name not given. Type locality is on a branch of Big Walnut Creek 7.6 mi north-northeast of the State Capitol, Austin. Consists of a basal glauconitic calcarenite that grades upward into white calcilutite sequence with abundant GRYPHAEA AUCELLA in middle part and beds of EXOGYRA LAEVIUSCULA and E. TIGRINA in topmost part. Is about 70 to 90 ft thick in Travis Co. Locally (vicinity of Pilot Knob) includes Pilot Knob tuff (new) in middle part of unit. Overlies disconformity at top of undifferentiated Austin; locally and to southwest is disconformable with overlying Burditt formation. Both Dessau and Burditt thin southwestward through Travis Co. Further southwestward, upper disconformity increases to extent that in Comal Co, the lower Taylor marl rests on Dessau; northeastward the contact is transitional in Bell Co. Columnar sections and correlations (pl. 16). Age is Late Cretaceous.

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