26 DEEP-SEA SEDIMENTS. 



and " remained as fathomless and as mysterious as 

 those of the firmament above." * 



The little information however which has been col- 

 lected thus far, shows that the bottom of the sea at 

 great depths consists of very fine sediment, the accu- 

 mulation of countless ages, deposited by the water. 



The Report of the Challenger Expedition states that, 

 " two kinds of sediment may be said to cover the area 

 inhabited by the abyssal fauna " f namely the " Glo- 

 bigerina Ooze" and the "Red Clay" the latter of 

 which seems to be found principally in the deeper 

 depressions, while the better known globigerina ooze, 

 is a fine calcareous deposit, somewhat resembling 

 chalk, and composed to a great extent of shells, more 

 or less broken or decomposed." Some of the speci- 

 mens of this "mud," brought up by the surveying 

 parties who were taking soundings previous to laying 

 down the first transatlantic telegraph cables in 1858, 

 from depths sometimes exceeding two miles, were found 

 on examination by Professor Huxley to be almost 

 entirely composed of minute shells of the genus Glo- 

 bigerina, whence the ooze has taken its name. Its 

 consistency when first brought up is described as akin 

 to that of putty. 



The American hydrographer Lieutenant Maury 

 describing this remarkable sediment says: 



" The unabraded appearance of these shells, and the almost 

 total absence of any detritus from the sea, or foreign matter, 

 suggest most forcibly the idea of perfect repose. Some of the 



* The Physical Geography of the Sea, by Lieut. Maury, 1877, p. 206. 



f See Scientific Report of the Challenger Expedition, Vol. i., pp. 41 

 to 43 of Introduction. 



Elements of Geology, by Sir Chas. Lyell, Bart., F.R.S., pp. 

 317318. 



