148 PRINCIPLES OF STRATIGRAPHY 



Per cent. Grams per liter. 



CI 55292 1968 



Br 0.188 0.07 



SO4 7 . 692 2 . 74 



CO3 o . 207 o . 08 



Na 30.593 10.89 



K 1. 105 0.40 



Mg 3.725 1.33 



Ca 1. 197 0.43 



99-999 35-62 



Besides the predominating seven elements in the sea, there are 

 traces of numerous others, the quantity of which, precipitated as salts 

 in the evaporation, are figured in the above table of Dittmar with the 

 calcium carbonate. The following additional elements have been de- 

 tected (for details see Krummel-20: ^/d, 218): Aluminium (Al), 

 Arsenic (As), Barium (Ba), Boron (B), Caesium (Ce), Cobalt 

 (Co), Copper (Cu), Fluorine (F), Gold (Au), Iodine (I), Iron 

 (Fe), Lead (Pb), Lithium (Li), Alanganese (Mn), Nickel (Ni), 

 Phosphorus (P), Rubidium (R), Silicon (Si), Silver (Ag), 

 Strontium (Sr), Zinc (Zn), together with dissolved Oxygen (O), 

 Nitrogen (N), and Carbon dioxide (CO.), the latter estimated at 

 18 times the amount contained in the atmosphere, (Chamberlin 

 and Salisbury-3 : s~5)- 



The weiglit of the sea water, as a whole, being taken at 

 138 X 10^"^ metric tons (Chapter I, p. 3), and the average per- 

 centage of salts by weight as 3.5, we obtain for the total amount of 

 salt in the sea the product of 4.84 X 10^" metric tons. The volume 

 of salt, resulting from a complete evaporation of the oceans, would 

 depend on the average specific gravity of the salt, which may be 



4.84 



taken at 2.22. This would give us- X lo'*^ or 2.18 X 10^" cubic 



*^ 2.22 



meters, or 21.8 million cubic kilometers, a quantity sufficient, if 

 spread over a level sea bottom of 361 million square kilometers, to 

 make a layer more than 60 meters thick. Of this 47.5 meters would 

 represent sodium chloride or common salt, 5.8 meters magnesium 

 chloride, 3.9 meters would represent magnesium sulphate, 2.2 

 meters calcium sulphate, and 0.6 meter the remaining salts. The 

 total quantity of salts forms a mass three times as great as the con- 

 tinent of Europe, or a little more than half the volume of land in 

 Asia, which has 41.6 million cubic kilometers. 



* With the average salinity taken as 35.6 permille. 



