Illustration Sheet
U. S. GEOLOGICAL SURVEY CHARLES D. WALCOTT, DIRECTOR
Fig. 4.-TERRACE OF OLD ALLUVIUM UPON UPPER BEDS OF THE EDWARDS LIMESTONE, COLORADO VALLEY, WEST AUSTIN, Showing previously eroded surface ot the limestone.
TEXAS AUSTIN QUADRANGLE
Fig. 5.-RESIDUAL GRAVEL OF THE UVALDE FORMATION IN THE BLACK PRAIRIE REGION. Composed of flint nodules derived from the Edwards limestone in the region of the Edwards Plateau.
Fig. 6.-MINOR BLOCK FAULTING IN THE EDWARDS LIMESTONE, BARTON CREEK. Showing the type of faulting in the Balcones fault zone.
Fig. 7.-TYPICAL EXPOSURE OF TAYLOR MARL, BLUE BLUFF, COLORADO RIVER. Remnant of a gravel terrace caps the bluff at the right.
Fig. B.—CLIFF OF AUSTIN CHALK, ONION CREEK. Interbedded volcanic tuff at the base of the exposure.
Fig. 9.-GLEN ROSE FORMATION, FORMING WEST BLUFF OF MOUNT BONNEL. Old alluvial plain of the Colorado River, cut in the Edwards Plateau, is shown in the valley on the left.








