THE DEPTH AUD MAKINE DEPOSITS OP THE PACIFIC OCEAN. 153 



DISTRIBUTION OF MARINE DEPOSITS IN THE PACIFIC 

 OCEAN. 



Dr. Agassiz's explorations have greatly increased the area with depths 

 between 2000 and 3000 fathoms in the southeastern Pacific, which likewise 

 increases the area covered by deposits of Globigerina Ooze, for this type of 

 deposit is most widely distributed in these depths. 



On Map II. accompanying this paper the distribution of the different 

 types of deposits is shown by different colors. No attempt is made to 

 indicate the distribution of all the individual types of terrigenous deposits, 

 Coral Muds and Coral Sands being shown by a yellow color, while the re- 

 maining types of terrigenous deposits (Volcanic Muds and Sands, Green 

 Muds and Sands, Red Muds, and Blue Muds) are all included in the blue 

 color on the map. A similar map was published in Dr. Agassiz's prelimi- 

 nary report^ in January, 1902, the principal modification being the large 

 area of Globigerina Ooze now introduced in the southeast Pacific, as the 

 result of the recent cruise of the "Albatross." 



Planimeter measurements give the following approximate areas cov- 

 ered by the various types of deposits within the Pacific Ocean, as already 

 defined, and the percentages to the total area : — 



Square Miles. Per Cent. 



EedClay 29,300,000 47.0 



Globigerina Ooze 16,540,000 26.5 



Diatom Ooze 3,630,000 5.9 



Eadiolarian Ooze 3,330,000 5.5 



Pteropod Ooze 120,000 0.2 



Coral Mud and Sand 1,.330,000 2.1 



Other terrigenous deposits 8,040,000 12.8 



62,290,000 100.0 



This table shows that by far the most important deposit in the Pacific 

 is the Red Clay, which is estimated to cover an area nearly twice as large 

 as that covered by Globigerina Ooze, and about eight times greater than 

 that covered by either Diatom Ooze or Radiolarian Ooze. A glance at 

 the map corroborates this statement, for it is seen that Red Clay occupies 



1 AJe7ti. Mus. Comp. ZooL, vol. XXVI., no. 1, Map lA. 



