THE TIMBER BELT OR SABINE RIVER BEDS. 



29 



Fig. 1. 



(,seale.— 1 iiicn= t toot.; 



Section of undulating clay and sand strata- 



a, clay; b, sand. 



The dip varies from 1 to 7 degrees, and is very undulating, often showing 

 a local trend to the north. Lignite beds are very plentiful throughout the 

 series and vary from one to eight feet thick. They are generally conformable 

 in a general way with the overlying and underlying strata, but sometimes 

 they are unconformable. 



Twelve miles below Bastrop is " Red Bluff." This is about a hundred feet 

 high and capped with a Quaternary conglomerate from three to twenty feet 

 thick, and composed of pebbles of flint, chert, quartz, feldspar, and jasper, one- 

 sixteenth to six inches in diameter, and cemented in a highly ferruginous 

 sand. It frequently contains patches of red and mottled sand, and is of a 

 bright red color. The foot of the bluff is covered by immense blocks that have 

 fallen from this bed. Underneath the conglomerate is a bed of white Ter- 

 tiary sand, in places thirty feet thick. It is frequently rusted on the surface 

 from the ferruginous solutions running down from the overlying conglomer- 

 ate. Below the sand are fifty feet of interlaminated seams of chocolate clay, 

 sandy clay, and gray sand. At the base of the bluff the sand bed contains 

 large black indurated masses of sandstone, as at Rocky Rapids, on the 

 Brazos. The whole bluff has a red appearance, the effect of which is greatly 

 enhanced by the patches of unstained white sand occasionally seen. Half a 

 mile below this point is seen a similar though smaller bluff of the same strata. 

 For two and a half miles below this are seen scattered outcrops of gray 

 sands and plastic clays, containing lignite deposits. Bombshell Bluff is 

 seventeen miles by river below Bastrop, and is in the southern part of Bas- 



