Named as formation at base of Taylor Group; from Sprinkle, a station on the Missouri-Kansas-Texas RR north of Austin, Travis Co, TX in Ouachita tectonic belt province. Type locality is exposure along Little Walnut Creek about 1/2 mi west of bridge on the old Austin-Manor highway; here, just south of intersection of Loyola Lane and Tulsa Drive in River Bend subdivision, Austin, TX the unit is faulted into a small graben. Gradational contact with Big House Chalk (below); disconformable contact with Pecan Gap Formation (above) is sharp and burrowed (burrows extend as much as 2 or 3 ft into underlying claystone and are filled with overlying chalky marl). Is considered a clay lithosome of the Austin Chalk, and thickens basinward both by thickening of beds and through lateral replacement by the Big House Chalk, Burditt Marl, and Dessau Limestone; is thus separated from the Taylor Division by a disconformity and is part of the Austin Division of Hill (1901) sensu Hill (1894) and others. Formerly called "Lower Taylor Marl". Is greenish-gray to brownish-gray, unctuous, montmorillonitic claystone, slightly calcareous in lower 20 or 30 ft. Is as thick as 340 ft in Travis Co. Most characteristic fossil is EXOGYRA PONDEROSA s. l.; other fossil mollusks listed. Is Late Cretaceous in age.

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

Paleomagnetic (a.f. demagnetized) data indicates the Upper Cretaceous Sprinkle Formation in the Ouachita tectonic belt province of TX possesses a weak remanent magnetization of normal magnetic polarity. The normal polarity is assumed to be primary magnetization, and is interpreted to represent deposition during the Gubbio (Italy) normal polarity zone B+ (Campanian to early Maestrichtian).

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