THE MINERAL MATTER OF THE SEA 473 



TABLE II 

 Mineral Matter in Solution in One Cubic Mile of Average River Water 1 



Constituents Tons 



Calcium carbonate (CaC0 3 ) 326,710 



Magnesium carbonate (MgC0 3 ) - . . 112,870 



Calcium phosphate (Ca 3 P 2 C>8) 2,913 



Calcium-sulphate (CaS0 4 ) - 34,361 



Sodium sulphate (Na 2 S0 4 ) 31,805 



Potassium sulphate (K 2 S0 4 ) 20,358 



Sodium nitrate (NaN0 3 ) 26,800 



Sodium chloride (NaCl) 16,657 



Lithium chloride (LiCl) - - - - - 2,462 



Ammonium chloride (NH 4 C1) 1,030 



Silica (Si0 2 ) 74,577 



Ferric oxide (Fe 2 3 ) 13,006 



Alumina (A1 2 3 ) 14,315 



Manganese oxide (Mn 2 3 ) -,-.-.-- S,7°3 



Organic matter - 79,020 



Total dissolved matter - 762,587 



Time necessary for the accumulation 0} the mineral matter 0} the 

 sea. 2 — The discharge of water into the sea by rivers is estimated at 

 6,524 cubic miles per year. 3 This volume of water is estimated to 

 carry to the sea 0.433 cubic miles of mineral matter in solution. 4 

 At this rate, it would take about 10,500,000 years for the streams to 

 carry to the sea an amount of mineral matter equal to that which it 

 now contains, and at this rate it would take about 54,000,000 years 

 for an amount of mineral matter equal to all that is now above the 

 sea, to be dissolved and carried to the oceans. 



The sodium chloride makes up about 2 . 2 per cent, of the mineral 

 matter in solution in river water. The same substance constitutes 

 nearly 78 per cent. (77 . 758 per cent.) of the mineral matter in the sea 

 water. The 2.2 per cent, of 0.433 cubic miles is 0.0095 °f one cubic 



1 Murray, Scottish Geographical Magazine, Vol. Ill, p. 77. 



2 Most of the following computations have been made or verified by Messrs. J. H. 

 Lees and E. W. Shaw. 



3 Murray, op. cit., Vol. IV, p. 41. 



4 Murray, loc. cit., states that the amount of mineral matter carried to the sea 

 annually by rivers is 1.183 cubic miles; but the data on which this calculation is based 

 {op. cit., Vol. Ill, p. 76, 77) give only 0.433 cubic miles. 



