46 BULLETIN 61, U. S. DEPAETMENT OF AGRICULTURE. 



B. K. Brockington submitted several brines to the Cooperative Laboratory from this 

 locality, and the results upon these closely corroborate the samples taken by Free 

 and Jones. 



It should be noted also that borate compounds are found in Death Valley; just 

 north of Bennett's Wells is the Eagle Borax Works, now abandoned. Surface crusts 

 were gathered at this place and refined. North of Furnace Creek Ranch is an old 

 borax mill. The playa in the vicinity was the source of the borate minerals. This 

 deposit is practically at the mouth of Furnace Creek. The well-known deposits of 

 colemanite in Furnace Creek Canyon were undoubtedly the source from which the 

 marsh borax in the valley came. 



The borax deposits in Death Valley are no longer worked. No salt has been pro- 

 duced on account of difficulty of access and climatic conditions. The potassium 

 content of the brine is probably too low to warrant attempts at separation. Until 

 deeper borings are made in the smooth salt area and the composition of the brines at 

 depth determined, Death Valley must still be looked upon as a possible source of potas- 

 sium salts. It is, however, a matter of reasonable doubt whether a greater content of 

 potassium will be found at depth. Death Valley is of interest in that it indicates a 

 transition stage in the formation of a saline deposit at depth. It would not take a very 

 great increase in rainfall to bring down debris sufficient to cover and seal the present 

 salt deposit. 



Since the foregoing was written the results of borings and analyses upon the brines 

 obtained therefrom by the United States Geological Survey became available and are 

 given below. 



Log of United States Geological Survey boring No. 3, Death Valley, Cal. 



Salt (1^ inches thick on surface). Feet. 



Mud, light brown, containing coarse salt crystals 1. 5 



Salt layer 2 inches thick with flow of brine at bottom. 



Mud, soft brown 29. 



(Small flow of warm water at depth of 30 feet.) 



Mud, yielding seepage of water 2. 5 



Clay or mud and crystals of salt .- : 1. 5 



Salt : 5 



Mud, black, and crystals of salt 1. 5 



Salt 5 



Mud, black, and crystals of salt 15. 



(Water all shut off and auger cut without seepage.) 



Salt 3 



Clay, black, with occasional thin salt layers ; 3. 7 



Salt, crystalline, hard, containing layers of black clay mixed with salt crystals 



1 to 4 inches in thickness at intervals of about 2 feet 8. 5 



Mud 5 



Salt, crystalline, apparently solid 13. 



Mud 2.2 



Salt, crystalline 3. 8 



Clav, black 1. 



Salt, crystalline 2. 



Clay, black, containing salt crystals 10. 5 



(No water encountered in the lower part of the well.) 



Total 96.0 



