150 THE IRON ORE DISTRICT OF EAST TEXAS. 



clay, such as found on the Lewis Watkins headright, and by a proper course 

 of working. By such operations the texture of the clay would be much im- 

 proved and the ware closer bodied and better fitted to meet the requirements 

 of the market. The loss in firing would also be lessened to such an extent 

 as to render the clay profitable to work. 



In the bank of a cutting on the Texas and Pacific Railway, on the south 

 side of Walnut Creek, on the Daniel McGray headright, there is an exposure 

 of a pale blue plpsticclay. It is seen in the south end of the cutting, having 

 a depth of exposure of one foot, but its real thickness or extent is not known. 

 It probably, judging from the contour of the region, extends for a consider- 

 able distance both east and west of the railway track. 



The following is a section of the cutting: 



1. Brown sand, containing bowlders of ferruginous sandstone, laminated 



iron ore, and gravel 1 foot. 



2. Horizontally lying stratified sand and clay, the clay partings and the 



sand beds having thicknesses of clay one inch, sand two to six inches, 4 to 6 feet. 



3. Dark blue, almost black, clay in more or less jointed condition, some of 



the pieces being spherical and concentrically formed, others cuboidal, 



and all having a tendency to stratification 3 to 6 feet. 



4. Grajush greensand 1 foot 4 inches. 



5. Pale blue or lead colored clay at south end of cut 1 foot.-f- 



This pale colored clay (No. 5) is covered by the brown gravelly sand (No. 

 1) of section. 



N Fig. 9. S 



a, Brown sand, b, Stratified sand and clay, c, Joint clay, d, Greensand. e, Pale blue or 



lead colored clay. 



4. MISCELLANEOUS CLAYS. 



The miscellaneous clays not included in the brick earths, fire clays, and pot- 

 tery clays consist chiefly of black or dark colored micaceous clays, which are 

 generally too impure to be of any economic value. 



A deposit of dark blue clay is bored through by the wells of the Marshall 

 Water Works. This clay is strongly impregnated with sulphuret of iron 

 and gives the water of the wells a strong smell of sulphureted hydrogen gas. 



Throughout the eastern part of the county, but generally at too great 

 depths to be of any economic use, there are several extensive deposits of clay 

 or sandy clay, known in the region as soapstone. 



The accidental constituents or impurities in these clays are iron, either as 



