ORIGIN OF SALT DEPOSITS 497 



"Applying these criteria to the Salina deposits of eastern Xorth Amer- 

 ica, we find, first, that while gypsum and salt occur in alternating layers, 

 there is a notable absence of the potash salts such as characterize the 

 great Zechstein salt deposits of North Germany; second, the character- 

 istic separating layers are found as a rule, but, third, they are entirely 

 unfossiliferous, these Salina deposits being noted for their barrenness of 

 organic remains, and, finally, fourth, there are no undoubted marine 

 equivalent deposits carrying the normal oceanic fauna of the time any- 

 where within reach of the salt deposits. Schuchert, it is true, draws a 

 connection with the Atlantic across northern New Jersey and south- 

 eastern New York, but (as I have already shown) it is here that the 

 clastic deposits are thickest, and so there must have been a broad land 

 area still farther east from which the material composing these beds was 

 derived." 



"It is thus evident that this mode of formation of salt deposits is not 

 applicable to the Salina deposits of North America." 



In considering the deposits formed according to the second or bar 

 theory, we are again "confronted with the fact that such deposits of salts 

 should be fossiliferous, for the amount of marine life destroyed in the 

 Karabugas is enormous, and the accumulation of organic remains in 

 these deposits is unparalleled in the neighboring sea. Again, such accu- 

 mulations of salt should be in close proximity to deposits formed under 

 more normal marine conditions, for the saline gulf and, the sea which 

 supplies the salt water are separated only by a narrow bar. The failure 

 of both these criteria in the Salina formation of North America makes 

 it evident that this method of accumulation could not have been the one 

 to which these salt deposits owe their existence." 



The third or desert theory of deposition regards the salt as obtained 

 from the connate sea-water imprisoned in the older marine rocks, to- 

 gether with the additional amount of NaCl absorbed by marine elastics. 

 Analyses have shown that the amount of NaCl in recent marine elastics 

 may be as 8 per cent of the mass of the sediment (see analysis quoted in 

 the paper cited). The connate water alone would furnish an amount 

 probably not short of 1 per cent. 



"To form a bed of salt 100 feet thick and covering an area of 2,600 square 

 miles (which is probably more extensive than any single salt layer in the New 

 York or Michigan basins) would require, on the basis of 1 per cent <»l* salt 

 content, the destruction of an older marine clastic formation 10,000 feel thick 

 and covering the same area. The same salt bed might be derived from the 

 destruction of an old marine formation TOO feet thick and covering :u\ area o\' 

 260,000 square miles, or an area equal, approximately, to that of the States 

 of Ohio, Indiana, Michigan, Wisconsin, and a part of Illinois, The area tribu- 



XXXIV— Bull. Geol. Soc. Am., Vol. 24, 1012 



