1914-] CONCEPTION AND TRINITY BAYS, NEWFOUNDLAND. 447 



ing considerable COo. According to the " Challenger researches," 

 when a large quantity of carbonic acid was found in oceanic waters 

 it was " at the bottom over Blue Muds." The great difficulty in 

 this series of reactions is to find in nature the conditions which will 

 bring about the liberation of the excess CO2 from the bicarbonate 

 to form the carbonate, such as evaporation, increase of tempera- 

 ture, or agitation. If quiet waters are postulated for the formation 

 of manganese carbonate it is quite conceivable that either of the 

 conditions such as evaporation or an increase of temperature might 

 easily be obtained particularly in shoal waters. It is very doubtful, 

 however, in the case of agitated waters whether laboratory condi- 

 tions can be simulated in nature, because of oxidizing influences 

 whereby some oxide of manganese would form more readily than a 

 carbonate. After the carbonate had formed there would be no 

 particular difficulty in conditions being present which would bring 

 about the oxidation of the carbonate because of the presence of 

 oxygen. The excess oxide of manganese found in the Newfound- 

 land deposit may in part have originated in this way. 



Penrose (20: 563) suggested that "carbonate of lime on the 

 sea floor may have acted as a precipitating agent " or as it passes 

 through the sea-waters in the form of organic remains or mineral 

 particles a substitution takes place whereby a solution of the calcium 

 carbonate with a corresponding precipitation of manganese occurs. 

 Fermor develops this suggestion in his explanation of the origin 

 of the deep sea nodules as quoted on page 444. Such an explanation 

 might apply to the origin of the primary oxides of the Newfound- 

 land deposits. 



It is possible that manganese may have been present in the sea- 

 water as a chloride. L. De Launay (5: 533) says that "manganese 

 chloride with sodium bicarbonate produces manganese carbonate." 



When we stop to consider that manganese only averages .07 per 

 cent, of the lithosphere (Clark, 2 : 32) and is 70 times less abundant 

 than iron which averages 4.43 per cent, and compare with these 

 figures the percentage of manganese in the deposits under con- 

 sideration which is 24.64 we can obtain some idea of the enormous 

 concentration there has been in the production of these deposits. 



