THE IRON ORES OF EAST TEXAS. 67 



seam of dark brown and very hard siliceous sandstone, varying from one 

 to six inches thick, and averaging about one and a half inches. It ad- 

 heres closely to the iron ore bed, though the line of separation is sharp and 

 well denned. Above this is a gray sandy deposit, becoming more clayey 

 and ferruginous towards its base, and varying from one to sixty feet thick. 

 This latter thickness is, however, very extreme, and the average is about 

 six to eight feet. As a rule the thickness of the ore depends, in a general 

 way, on the thickness of the overlying sand bed, it being thicker where 

 the sand is less than fifteen or twenty feet than where it is greater. Other 

 conditions, however, enter into the thickness and continuity of the iron 

 ore bed, which will be mentioned under the heading of Origin of Ores, and 

 which often upset the working of this rule. Nevertheless, the general fact 

 holds good that when the ore is capped by a great thickness of sand, it is 

 liable to be thin and discontinuous. The hills on which the ore occurs are 

 steep and show a broad flat plateau-like surface, heavily capped with post oak, 

 blackjack and hickory, generally of a small size, but very dense. The ore 

 crops out on the brink of these hills, forming a protruding rim or crown, 

 and often covering the slopes with great masses which have broken off from 

 the main bed. These plateaus are sometimes as much as twenty square miles 

 and more in area. They are often deeply cut by the ravines of creeks 

 which have originated in springs in the superficial sand and which flow away 

 from the plateau in all directions, cutting deep gullies and exposing the ore 

 bed along their courses. On top of these plateau areas the covering of sand 

 often conceals the ore for a distance of several miles at a time, but it is always 

 found cropping out at the top of the slopes, and in wells, proving its continu- 

 ity over very large areas. But, as has been stated above, when the overlying 

 sands and sandy clays reach a great thickness, the ore grows thin and very 

 often runs out altogether. Frequently there are found in the iron ore region 

 beds of conglomerate composed of ferruginous pebbles in a matrix of sand. 

 These are found along the rivers and creeks, and often form a prominent 

 feature in the topography of the country. They will be treated under " Con- 

 glomerate Ores." The general distribution of the iron ores in special regions 

 can be best understood by a detailed description of such localities, and below 

 is given an account of the areas that have been visited: 



Cherokee County. — The ore belt in this county begins at its southern end, 

 about three miles north of the town of Alto, and runs in a northwesterly and 

 north northwesterly direction through the county into the southern part of 

 Smith County. Going north from Alto the ore is found capping small flat- 

 topped hills and narrow ridges, of limited extent, until we come within five miles 

 of New Birmingham. These ore-bearing areas show the usual brown laminated 

 ore, but near Alto, their extreme southern limit in the county, it has not reached 



