KEPORT ON THE DEEP-SEA DEPOSITS. 
213 
Taking the Challenger researches in conjunction with those of Sir James Ross’s 
Antarctic Expedition and other observations, it seems to be, indicated that a great zone 
of Diatom Ooze of varying width surrounds the South Polar regions, as represented on 
the accompanying chart. This zone lies for the most part between the Antarctic Circle 
and the latitude of 40° S., and may be estimated to cover about 10,880,000 square miles 
of the sea bottom in these regions. There is a small patch of Diatom Ooze in the 
North Pacific, which may be estimated at about 40,000 square miles. 
Globigerina Ooze. 
This name was in the first instance applied to the mud collected when sounding 
out the greater depths of the Atlantic Ocean in connection with telegraph cables, because 
a large percentage of this mud or ooze was made up of the small Foraminiferous shell 
named Globigerina bulloides. The term Globigerina Ooze, which has become quite 
familiar and well established, is at once appropriate and distinctive, and is now adopted 
for all those deposits which are chiefly made up of the Foraminiferous shells belonging 
to the family Globigerinidse. The first specimens of the ooze were probably procured by 
Lieutenant Berryman of the United States Navy in the North Atlantic, and were 
described in some detail by Ehrenberg and Bailey in 1853. Many subsequent writers 
have described specimens that were afterwards procured from other regions of the 
ocean. Were all the deposits which contain 10 or 15 per cent, of these Foraminiferous 
shells classed as Globigerina Ooze, then this deposit would be by far the most extensive 
of the deep-sea deposits, for some species of these shells are present in greater or less 
abundance in all the types of marine formations from Equator to Poles. Near land, 
however, their presence is sometimes wholly masked by the abundance of land debris 
or exuviae of shallow- water organisms, and in the greatest depths of the ocean these shells 
are absent, or at least do not accumulate on the bottom so as to form a calcareous 
deposit. In this Report, as a general rule, a deposit has not been classed as a Globigerina 
Ooze unless it contains over 30 per cent, of carbonate of lime, principally made up of the 
dead shells of these Foraminifera. There was at one time much discussion as to whether 
those Foraminifera, which are in this Report called pelagic, lived at the surface of the sea 
or on the bottom of the ocean; this question has been, we believe, definitely settled in 
favour of the former view, as will be pointed out in detail later on. The following is a 
list of the pelagic Foraminifera that were taken in the surface nets during the cruise of 
the Challenger, and it is the dead shells of these species which, having fallen to the 
bottom of the sea, make up the principal part of the carbonate of lime present in the 
great majority of pelagic deposits, and especially in all those denominated Globigerina 
and Pteropod Oozes : — 
