Navarro and Taylor Groups, undivided (TXKnt;0)

State	Texas
Name	Navarro and Taylor Groups, undivided
Geologic age	Phanerozoic \| Mesozoic \| Cretaceous-Late [Gulfian]
Original map label	Knt
Comments	On Austin Sheet (1974) in areas where Pecan Gap Chalk is not present because of gradation to marl similar to that of the Marlbrook and Ozan Formations. Upper 250 ft, mostly silty, calcar. clay with sandst beds and concretionary masses near top, some interbeds of sandst. near base. Lower 200+- ft, quartz sand, fine grained, silty, locally calcar. concretions in discontin. beds, lt. gray; marine megafossils. Mapped on Sherman Sheet (1967) east of Sabine River. Taylor Group includes claystones of the Sprinkle Formation at base, chalk or marly limestones of the Pecan Gap Fm, and overlain by claystones of the Bergstrom Formation.
Primary rock type	clay or mud
Secondary rock type	fine-grained mixed clastic
Other rock types	sandstone; limestone
Lithologic constituents	Major Sedimentary > Clastic > Mixed-clastic > Siltstone-Mudstone (Bed) Incidental Sedimentary > Carbonate > Limestone (Bed)
Map references	Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000
Unit references	Bureau of Economic Geology, 1967, Sherman Sheet, Geologic Atlas of Texas: University of Texas at Austin, Bureau of Economic Geology, scale 1:250,000.
Geographic coverage	Bastrop - Bell - Milam - Travis - Williamson