104 PROCEEDINGS OF THE ACADEMY OF [1894. 



1. Brownish-yellow sand and gravel 5 to 6 feet 



2. Brown coffee- colored clay with great quantities of 



gypsum crystals 2 to 6 feet 



3. Brown and yellowish- brown sand and ledges of indu- 



rated sand or ferruginous sandstone, the sands con- 

 taining Anomia ephippioides, Gabb ; Plicatala 

 filamentosa Conrad ; Spirorbis leptostoma, Swain ; 

 Volutilithes petrosa Conrad; and other fossils, 35 over 40 feet 



Going eastward the Navasota River section is practically the 

 same as on the Brazos. Neocene beds occur a short distance north 

 of Rock Creek, in Grime County. The Frio clays do not appear 

 anywhere along this river, but overlaps of the Neocene Nava- 

 sota beds (Oakville beds of Dumble) completely cover them. The 

 Fayette sands extend to about the mouth of Gibbon's Creek, or a 

 short distance above, and from there to near the northwest corner of 

 Madison County the whole country is occupied by the gray sands, 

 greenish blue lignitic clays and lignites of the Yegua showing prac- 

 tically the same sections as those found along the Brazos. Very 

 few sections of any value are found along this river, but the few 

 obtainable, supplemented by those farther inland, show the general 

 sequence here given. The gypseous clays are found in this region 

 lying close to the base and occupying the same position as near Elm 

 Creek on the western side of Brazos County. 



The Trinity River section shows the typical Yegua clays in many 

 of the bluffs. A section at Hyde's Bluff, in the southwestern portion 

 of Houston County, shows : 



1. Dark yellowish-brown clayey loam 8 feet 



2. Conglomerate of nodular iron ore, silicious pebbles, 

 silicified wood, coarse brown sand and fine gravel. 2 feet 



3. Dark blue sandy clay with iron pyrites. ... 10 feet 



4. Lignite 2 inches to 2 feet 



'to 



02 



£> 5. Light grayish-blue sand and gray clay inter- 

 im laminated t 10 feet 



2 6. Liguitic 2 to 4 feet 



~£ J 7. Dark purple colored clay H feet 



8. Gray sand containing rounded and flat oval 

 shaped concretions of indurated gray sand, to 

 water = 4 feet 



— *_ . 



' Harris' MS. Monograph of Texas Tertiary Fossils. 



