THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 17 



BOTTOM SAMPLES COLLECTED DURING THE FOURTH EX- 

 PEDITION OF DR. ALEXANDER AGASSIZ, 1904-1905. 



The number of samples received was one hundred and six, but, unfor- 

 tunately, a large proportion of these was not available for full description. 

 Thus, in no less than twenty-nine cases, the labels could not be deciphered, 

 most of them apparently terrigenous deposits. The labels indicating the 

 position of each sample were not stuck on the bottles, but placed inside 

 them, in contact with the deposit; curiously enough, in the case of the 

 terrigenous deposits, the labels were, with a few exceptions, totally de- 

 stroyed, while they were relatively well preserved in the samples of pelagic 

 deposits. This is probably connected with the larger amount of decom- 

 posing organic matter in the terrigenous deposits. 



In ten cases the material had evidently been subjected to a certain 

 amount of washing, and could not therefore be looked upon as represent- 

 ing the deposit m situ, while in seven cases the material consisted of man- 

 ganese nodules or rock fragments without any true deposit. In this way 

 the number of samples fully described in the sequel is reduced to sixty. 

 These are distributed in depth as follows : — 



Samples from less than 1000 fathoms 3 



Samples from 1000 to 2000 fathoms 15 



Samples from 2000 to 3000 fathoms 41 



Samples from over 3000 fathoms _y 



Total 60 



The types of deposit to which these sixty samples are referred are as 

 follows : — 



Globigerina Ooze 36 



EedClay 16 



Green Mud 3 



Blue Mud 2 



Calcareous Mud 1 



Volcanic Sand 1 



Diatom Ooze J^ 



Total 60 



Between Panama and the Galapagos Islands the "Albatross" took 

 samples of Green Sand and Green Mud in 556 and 776 fathoms respectively, 

 off Mariato Point. About midway between Panama and the Galapagos 



