THICKNESS OF CRETACEOUS DEPOSITS. 227 



Eagle Pass Artesian Well Section. 



Feet. 



1 . S< >il and subsoil 14 



2. Yellow clay 26 



3. Bluish clay 50 



4. Sand with some gravel 110 



5. Black shale ; six inches coal 60 



6. Clayey sand 70 



7. Gray sand 30 



8. Sand ; small gravel 60 



9. Sand 20 



10. Gray slate 30 



1 1 . I >ark shale 55 



12. Coal 6 



1 3. Dark shales !) 



14. White sand ; gas 40 



15. Black shale 150 



16. Sand and shale 15 



17. Black shale 135 



18. Sand and shale ; gas 15 



19. Dark soft sand and shale 75 



20. Hard gray sand ; salt water 10 



21. Gray shale 50 



22. Gray sand 10 



23. Calcareous clay 370 



24. Dark clay 102 



Total 1,512 



This is important as giving us the relative dip of the beds. The coal 

 seam which crops out 5 miles above Eagle Pass is found here at a depth 

 of 525 feet, while at 1,512 feet the heavy sandstones which were noted 3 

 miles north of Carter's ranch, or 15 miles above Eagle Pass, have not 

 yet been reached. The estimate of dip at 100 feet to the mile is there- 

 fore seemingly not at all excessive. 



The materials below Eagle Pass are somewhat different from those 

 above. The sandstones are harder and the clays have a blue or greenish 

 hue; the lime, instead of being in the form of geodes or septaria, is 

 intermingled with the sand, or forms separate strata; and the fossils are 

 much more plentiful than in-any other division except the San Miguel 

 beds. I propose to call this deposit the Escondido beds. 



Escondido Beds. — The last exposures <>f the Coal series beds on the 

 river are at Porferio Diaz, where a greenish sandy clay with glauconite 

 was observed, and a mile below, on the same side of the river, where there 

 is a similar bed of sandy clay with indurated bowlders, streaks of lignite, 

 im press ions of Leaves (grasses), and logs of silicified wood. At the mouth 

 of Escondido river similar clay was seen, and a mile below there was 

 XXX— Bull. Geol. Soc. A.m., Vol, :'•, 1891. 



