THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 



BOTTOM SAMPLES COLLECTED DURING THE THIRD EXPE- 

 DITION OF DR. ALEXANDER AGASSIZ, 1899-1900. 



The bottom deposits collected by the "Albatross" during her 1899-1900 

 cruise were received at the Challenger Office shortly after the return of the 

 expedition, and were examined by Sir John Murray, Mr. James Chumley, 

 and Mr. Robert Dykes. Dr. Alexander Agassiz published some remarks on 

 the bottom deposits by Sir John Murray in the preliminary report already 

 cited. Most of the mineralogical determinations have recently been revised 

 by Dr. G. W. Lee, who has also examined the manganese nodules collected 

 during this cruise, which were not forwarded to the Challenger Office till 

 some considerable time after the deposit-samples. Dr. W. A. Caspari has 

 made a detailed study in the Challenger Office laboratory of the white pala- 

 gonitic tuff from Station 2, and his results will be found in an appendix to 

 this Report. 



The number of samples received from this cruise was 237, but, unfor- 

 tunately, as many as 160 of these could not be fully described owing to the 

 fact that in 97 cases the material had evidently been subjected to a certain 

 amount of washing before reaching our hands, and in 53 other instances the 

 amount of material available was too small to allow of a definite analysis 

 being made. In 9 cases the material consisted of manganese nodules or 

 rock fragments without any true deposit, and in one case the bottle in 

 which the sample was contained was without any label or number, and the 

 description of the material is, therefore, less important than it might other- 

 wise have been. From these various causes the number of samples fully 

 described in the following pages is reduced to 77. These are distributed 

 in depth as follows : — 



Samples from less than 1000 fathoms 7 



" 1000 to 2000 " 10 



" 2000 to 3000 " 59 



" " 3000 to 4000 " 



« " over 4000 " _1 



77 



