12 THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 



"Again in the channel separating the Paumotns from the Society Islands 

 a deposit allied to red clay, composed in part of Globigerinae, was found in 

 the deeper parts at a depth of somewhat over 2200 fathoms ; the Globigerinae 

 becoming mixed with large proportions of volcanic mud as we approached 

 the Society Islands. 



"Through the Paumotu Archipelago the soundings in less than 1400 

 fathoms are marked by the frequent occurrence of Pteropod ooze and of Glo- 

 bigerinae, but by far the greater number of soundings show a bottom made 

 up of Globigerinae and of coral sand in proportion to the distance from the 

 atolls ; the coral sand being coarser nearer the shores, gradually becoming 

 finer as we proceed seaward, and at the same time containing a larger per- 

 centage of GlobigerinsB or of Pteropod shells. . . . 



" A similar state of things is found to hold good with the deposits at the 

 stations occupied in the central Paumotus, as well as in the easternmost 

 islands of the Paumotus we visited. When the depths separating the islands 

 are greater, ... we find again red clay in depths varying from 2284 to 

 2467 fathoms containing a greater or less percentage of Foraminifera. Sim- 

 ilarly ... in the deep water which separates Anu Anuraro from Here- 

 heretue, in 2265 and 2524 fathoms, the bottom deposit is red clay with an 

 admixture of Foraminifera ; while at stations varying in depth from about 

 700 fathoms to nearly 2000 fathoms the deposit is made up of coral sand, 

 Pteropod ooze, and Globigerinae in different percentages, as in the deposits 

 of the north-western Paumotus. 



" The deep soundings between Hereheretue and Tahiti . . . were made 

 up of red clay and Globigerinae ; and on approaching Tahiti the coral sand 

 which characterized the vicinity of the atolls in the Paumotus is replaced 

 in the Society Islands by volcanic mud and volcanic sand and a small 

 percentage of Globigerinae. 



" One cannot fail to notice the frequent occurrence of particles of man- 

 ganese and of small manganese nodules in the deposits through the Paumotus 

 and Society Islands. 



"In the deep water between Nine and Tonga which culminates at 

 Station 186 (lat. 21° 18' S., long. 173° 51' W.) in 4540 fathoms, we meet 

 with red clay deposits containing Radiolaria, . . . though at Station 182 

 the red clay in 2882 fathoms contained a considerable percentage of 

 Globigerinae. 



" On the way from Vavau to Fiji we found volcanic mud to the westward 



