94 PROCEEDINGS OF THE ACADEMY OF [1895. 



overlaid directly by the brown and gray sands of the latest Tertiary. 

 The following section combined from two cuttings at Summit Station 

 shows the relations of the Frio clays to the overlying and underly- 

 ing deposits. 15 



,,5 1. Gray sand with silicious pebbles . 18 feet. 



-g 2. Conglomerate of silicious pebbles connected by a 

 «g ferruginous matrix adhering to brown ferrugi- 

 i_3 nous sandstone, found in boulder form and in 

 o connection with an irregularly deposited stratum 

 of ferruginous material changing gradually to- 

 m ward the north end of the cutting to a brown 

 §c or pale red crossbedded sand interlaminated in 

 places with lenticular shaped deposits of brown- 

 ish-blue or pink clay 10 to 13 feet. 



3. Mottled-blue and brown sand clay 20 " 



m 4. Pale watery-green sandy clay 20 " 



£ 5. Brown sandy clay 25 " 



6. Pale blue sand and clay 15 " 



£ 7. Dark blue clay with limy concretions and gypsum 



crystals in places 20 " 



od 8. Drab sandy clay becoming gradually the same as 



5 | No. 8 _ 30 « 



£ 9. Gray sandstones, coarse grained on top but chang- 

 es' ing to a fine grained blue stone at base ... 120 " 



Nos. 3 to 7 belong to the Frio clays. 



Many deposits of these clays occur in Jasper and Newton Counties 

 and extend almost to the Louisiana line. 



West of Corrigan, deposits of the same character, occupying a 

 similar position and of the same age, occur in the neighborhood of 

 Lougstreet, Montgomery County, and lately in an examination of 

 the section at Riverside quarries, on the Trinity, Mr. Dumble found 

 the same clays between two sets of sandstone and occupying the 

 same position as the deposit at Corrigan. 



While these deposits are only visible at intervals, often many 

 miles apart, their generally uniform appearance, constitution and 

 relatively coinciding positions between the overlying sands and cal- 



15 Third Annual Eeport Geol. Survey of Texas, p. 120. 



