452 GEOLOGY OF NORTHWESTERN TEXAS. 



gave one place the name of "Potato Mine." This class of ore will run as 

 high as seventy-eight per cent metallic copper. The blue clay is impreg- 

 nated with copper to such a degree that it can be profitably worked for the 

 copper it contains, as will be seen from the following statement regarding 

 the material taken from this locality. The clay bed at this place is four feet 

 thick. I make the extract from a report made by Prof. G-ustaf M. Westman, 

 an eminent Swedish mineralogist, who visited this property with me in 1889 

 for the purpose of making a thorough examination thereof. We collected the 

 clays from beds only a few inches from the surface. He says: 



"At the excavation (Isbel lead) we found three separate veins of copper of 

 a width, respectively, twelve by six inches, eight by three inches, and four 

 by two inches, and besides, immediately below the lower sandstone a stratum 

 of cupriferous marl extending the entire width of the tunnel, eight inches 

 thick, yielding fifteen per cent of copper. The cupriferous marl situated be- 

 low the sandstone, containing fifteen per cent of copper, can be estimated to 

 be worth at the place ten dollars per ton." 



Prof. Westman, in speaking of another place in the same vicinity, says; 



"Although almost all the ore scattered on the surface in nuggets had been 

 taken away, I only had to remove one foot of earth from the surface on the 

 three spots mentioned already in order to find large deposits bedded in the 

 clay. After washing this clay was found to contain ten per cent of copper 

 ore." 



The second stratum, running through the lower part of the Clear Fork di- 

 vision, has much the same appearance and the ore is very much the same. 

 On California Creek, in Haskell County, the principal part of the copper 

 found is the pseudomorph after wood. No prospecting has been done for 

 copper in this part of the country, and the only thing that could be seen was 

 at the outcrop. 



The following section was made at a hill on Paint Creek, in Haskell 

 County, near the old McKinzie Trail: 



1. Dark red clay, containing vertebrate fossils 10 feet. 



2. Conglomerate (bean ore) 6 inches. 



3. Red clay 4 feet. 



4. Thin bedded sandstone, with tracks of insects 10 inches. 



5. Red clay 4 feet. 



6. Blue clay, with copper ... 3 feet. 



7. Sandstone, concretionary 10 inches. 



8. Red clay, with clay concretions 8 feet. 



9. Thin-bedded sandstone 8 inches. 



10. Cross-bedded sandstone 10 inches. 



11. Conglomerate, with vertebrate fossils 6 inches. 



Total 33 feet 2 inches. 



