110 
SEVENTH ANNUAL MEETING OF THE 
been 13,000 years in formation. This rock-salt deposit is in*- 
terspevsed with lamellar deposits of “anhydrit,” which grad-' 
ually diminished toward the top and are finally replaced by 
mineral “polyhalit” which was composed of sulphate of lime,, 
sulphate of potash, and sulphate of magnesia. The situation 
in which this polyhalit predominates is denominated the 
“polyhalit region’’ and after it comes the “kiese rit region” in 
which, between the rock-salt strata, kieserit (sulphate of' 
magnesia), is imbedded. Above the kieserit lies the “potash 
region,” consisting mainly of deposits of carnallit, a mineral 
compound of muriate of potash and chloride of magnesia. 
The carnallit deposit is from 50 to 130 feet thick and yields 
the most important of the crude potash salts and that from.; 
which are manufactured most of the concentrated articles, in¬ 
cluding muriate of potash. 
“Overlying this potash region is a layer of impervious clay 
which acts as a water-tight roof to protect and preserve the 
very soluble potash and magnesia salts, which—had it not 
been for the very protection of this overlying stratum—would 
have been long ages ago washed away and lost by the action 
of the water percolating from above. After this clay roof is 
a stratum, of varying thickness of anhydrit, (sulphate of 
lime), and still above this a second salt deposit, probably 
formed under more recent climatic and atmospheric influences 
or possibly by chemical changes in dissolving and subsequent 
precipitation. This salt deposit contains 98 per cent, (often 
more) of pure salt—a degree of purity rarely elsewhere found. 
Finally above this are strata of gypsum, tenacious clay, sand 
and limestone, which crop out at the surface. 
“The perpendicular distance from the lowest to the upper 
surface of the Stassfurt salt deposits is about 5,000 feet (a lit¬ 
tle less than a mile), while the horizontal extent of the bed is* 
from the Harz Mountains to the Elbe in one direction, and 
from the city of Madgeburg to the town of Bernburg in another. 
“It must not be inferred from what has been said that the 
various strata succeed one another in regular order. To be 
sure, they occur according to certain well-marke<i physical 
and chemical laws, which together with local conditions and 
and geological disturbances, have fixed their relative posi¬ 
tions, but as the order of formative influences has varied so 
have the results succeeded one another in interchanging 
strata, and one deposit is found here higher, there deeper, 
than another. At some few places, through refts or fissures, 
surface water has entered, and either entirely carried away 
the potash deposits or changed them into secondary products. 
Resuiting from this latter action are beds of kainit, sylvinit 
