128 THE IRON ORE DISTRICT OF EAST TEXAS. 



a generally lower level, having an average altitude of about two hundred and 

 fifty feet, which gradually lowers towards the lake region in Louisiana. 

 Greenwood having an elevation of two hundred and twenty-two and Shreve- 

 port one hundred and ninety-five feet. 



Where the brown and gray sands meet in the vicinity of water courses 

 the brown occupies the upper ground lying along the margin and the gray 

 lies within the bottom lands — no brown being found in that area. Prom 

 this position it looks as if the gray sands belong to a newer formation or a 

 more recent period of the same age, and have been laid down since the pres- 

 ent system of drainage had its origin. 



The few sections obtained from this area show the gray sands to be un- 

 derlaid by brown, gray, and mottled clays; the mottled clay being mostly 

 unstratified, while the stratified brown and gray clays are frequently cross- 

 bedded and irregular in their deposition. 



Section of well on James Harkin headright, near the Louisiana State line. 

 Altitude two hundred and eighty feet: 



1. Clay soil . . 1 foot. 



2. Brownish clay 4 feet. 



3. Hard, smooth, laminated clay with occasional strata of gravel 18 feet. 



4. Gravelly clay — gravel more abundant than clay 3 feet. 



26 feet. 

 In some places on this headright the sands and clays are twisted and broken 

 and more or less cross-bedded. 



At Robertson's Ford a section of the river bank gives: 



1. Gray sand 1 foot. 



2. Mottled, brown, blue, and yellow unstratified clay 45 feet. 



3. Lignite . 6 feet. 



4. Dark blue sandy clay to water 3 feet. 



IRON ORES. 



The iron ore deposits of Harrison County consist mostly of laminated and 

 conglomerate ores, with a small quantity of nodular concretionary ore. The 

 laminated ores are found generally in a broken and fragmentary condition, 

 mixed with ferruginous sandstone, capping many or most of the hills within 

 the limits of the county or else lying buried under a superincumbent mass of 

 yellow or gray sand and showing no outcrops beyond a broken and fringed 

 end of the bed lying upon the surface of and protecting some bench-like ex- 

 tension of the sand hill. It is also frequently found in digging wells. This 

 ore is found in extensive deposits in various parts of the county. 



Along the margins of the streams and at a considerable height up the hills, 

 lying close to the water courses and even capping the low lying hills in the 



