254 Br. A. Holmes — Non-German Sources of Potash. 



Wittelsbach District, 



Alsace. 

 Oligocene marls 



Suria and Cardona 

 District, Spain. 



Oligoceneva&xls, sand- 

 stones , and limestones . 



Marls with rock-salt, 

 anhydrite, and gypsum. 



Southern Harz District, 

 Germany. 

 Triassic /Sands, sandstones, 



Upper Permian\ clays, and shales. 



Bock-salt and clay . . Upper rock-salt 



Anhydrite . . 



Dolomitic salt-marl . Salt-clay . . . 



Younger rock-salt. 



Anhydrite. 



Salt-clay. 



Zones of potash salts in 

 dolomitic marl . 



Rock-salt with bitu- 

 minous clays . . . 



Anhydrite . 



Dolomite. 



Green-grey marls . 



Zones of potash salts . Zones of potash salts. 



Lower rock-salt with Older rock-salt with 



partings of anhydrite, partings of anhydrite (year rings). 



Anhydrite and gypsum. Anhydrite and gypsum. 



, Eocene limestone . . Lower Permian limestone. 



Spa?iish Deposits. — Just before the war a zone of potash salts was 

 discovered in Catalonia, near Cardona, a locality already well known 

 for its rock-salt mines. The general succession has been revealed by 

 a large number of bore holes and by a series of shafts which mark 

 the beginning of the productive exploitation of the deposits. As 

 shown in the detailed sequence set forth above, there is a marked 

 likeness to the Southern Harz type of the German deposits. The 

 saline beds were evidently precipitated in a gradually subsiding 

 lagoon which covered parts of Barcelona and Lerida in Lower 

 Tertiary times. 



The structure of the deposits makes their commercial development 

 rather troublesome. At Suria ' the beds turn steeply over in a 

 monocline, the dip of which is about 70°. They are then again 

 brought near the surface by a fault, from which the beds continue to 

 dip in the same direction but at a much reduced inclination. At 

 Cardona the deposits are worked in the axis of a steep anticline, 

 where the continuity of the beds has been repeatedly broken by 

 faulting. Here the chief potassium salt is sylvite, which occurs in 

 nearly pure seams. At Suria, however, the salts are more varied. 

 Certain bands consist dominantly of carnallite, but generally there is 

 intimate admixture with rock-salt, and occasionally layers of sylvinite 

 appear. Numerous potash zones, alternating with rock-salt, and 

 of variable thickness and value, have been proved, the aggregate 

 thickness being equivalent to 60 feet of carnallite and 13 feet of 

 sylvite. The complete extent of the Spanish potash field has not 

 yet been determined, but it has already been explored over a belt 

 more than 6 miles long, and consequently very substantial reserves 

 may be anticipated. The first large shaft sunk by the Franco- 

 Belgian Syndicate, which has a concession at Suria, has now been 

 completed, and it is expected shortly to raise 1,000 tons of raw salts 

 per day. That production was not commenced during at least the 

 last year of the war was due mainly to German intrigues and political 

 troubles, the details of which need not here be discussed. 



1 E. M. Heriot, Mining Journal, vol. cxix, p. 753, December 15, 1917. 



(To be continued.) 



