SECTIONS OF CRETACEOUS DEPOSITS. 225 



In the upper portion I found Exot/j/ra ptinrfn-oxa, and great numbers of 

 other shells not yet determined. Above this the sandstone becomes 

 more calcareous, and in places is compacted and contains calcareous 

 nodules. Three miles south of Carter's ranch we found the teeth and 

 bones of a saurian in the concretions. The materials overlying this 

 become more clayey, as will be seen by the following section, made some 

 10 miles north of Eagle Pass : 



Section near Eagle Pass. 



Foot. 



Sand and silt 8 



Sandstone 2 



Clays displaying cone-in-cone structure <> 



Sandstone with laminae and nodules of calcite 1 



Clay, to base 8 



Above this there are sands with lime and greensand containing man}' 

 casts of fossils, Inoceramus and other bivalves, together with numerous 

 gasteropods. This continues to a point about 8 miles north of Eagle 

 Pass, below which these strata are soon covered by the next newer series 

 of deposits. 



The Coal Series. — This series comprises the ferruginous shales, brown 

 calcareous shales, brown calcareous clays, heavy bedded sands, shales, 

 sands, and yellow clay which accompany the coal seam worked at the 

 Hartz and other mines. 



The exposures along the river above the Hartz mine show the following 

 strata underlying the Reynosa beds of gravel and limestone : 



Section near the Hurt: Mine. 



Feet, 



Brown calcareous clays 40 



Ferruginated shales 40 



Uncompacted sands* 20 



Shale 20 



Heavy bedded sands 30 



Yellow clayf 20 



( !( .alf 4 



Purple shalef 6 



Sam! to riverf 



Just south of the Hartz mine there may he seen the only disturbance 

 of any considerable extent which was noticed in the entire section north 



* Western extremity "i coal seam, 

 I E \ posed just above ll.nl z m inc. 



