vaughan] ANACACHO FORMATION. 31 
described are here succeeded by fine-grained sandstones containing 
some mica. There are bands of red iron ore and many bits of hematite. 
The flora consists mostly of Opuntia, lignum \ ita\ some guajillo, some 
rhamnaceous shrubs, and mesquite. There was no grass, the ground 
between the cactus and the shrubs being barren. 
Although it can not be affirmed with certainty, it is quite probable 
that this change in the character of the rocks marks the boundary 
between the Cretaceous and the Eocene. 
STUDIES ALONG TURKEY CREEK AND THE NUECES RIVER, THE FRIO 
AND SABINAL RIVERS, BRACKETT AND UVALDE QUADRANGLKS (EAST- 
ERN KINNEY COUNTY AND UVALDE COUNTY). 
The sections along these streams are described in the discussions of 
the formations. 
ANACACHO FORMATION. 
This formation was defined by Hill and Vaughan in the Geology of 
the Edwards Plateau and Rio Grande Plain, etc. 1 It is the strati- 
graphic equivalent of the Upson clays of the Rio Grande section, and 
of the Taylor {Exogyra ponderosa) marls of central Texas. It overlies 
the Austin chalk, and is in turn overlain by sandy limestones, sand- 
stones, and clays. Its component rocks are either hard or soft yel- 
lowish limestones or yellow marls, the calcareous constituents being 
in excess of the argillaceous. 
The following section is taken from the report cited above: 
Section of the Anacacho Mountains, Kinney County. 
II. Anacacho formation: Feet. 
8. Scarp-making rock, forming the top of the hill. It is a hard, yellow, 
subcrystalline limestone. In the top a species of Alectryonia was found. 
About 30 feet below the top, great numbers of Gryphsea vesicularis occur, 
firmly embedded * 60 
7. Softer limestone: b, Soft, yellow, marly limestone, containing a large 
species of Cardium, 50 feet; a, Soft, white, chalky limestone, containing 
a species of Turritella with three prominent revolving stripe on each 
whorl (T. trilira Com?) , 30 feet; total 80 
6. Hard limestone ledges. The upper 30 feet is brownish, and contains 
great numbers of Exogyra ponderosa firmly embedded near the top. The 
next lower 20 feet is a yellowish, granular limestone with glauconitic 
specks. This bed forms a platform on the cast end of the Anacacho.. 70 
5. Ledges of yellow, ferruginous, not very hard, subcrystalline Limestone, 
forming the lower scarp on the east end of the hill 30 
4. Slope composed of marly limestone in the upper part, the lower portion 
yellow marls with fragments of a very large and coarsely corrugated 
Inoceramus 20 
3. Yellowish limestone, weathering into nodular chunks, iron-stained along 
the weathering cracks. Contains some poorly preserved fossils — Tri- 
gonia (?) , Mactra, and a finely-ribbed Lima 10 
lEighteenth Ann. Rept. D. S. Geol. survey, Part II, 1898, pp. 240, 241. 
