10 



lo-^ ^ question whether any of the existing sedimentary rocks were 

 laid down at great depths is still to be answered. An especiallv 

 h°^^f °i;^%Pf^l%^' /°^ °^f understanding of geosynclinal ?ocks, and 

 wh?o? JL--^i. ^^^'^^^ mountain chains, relates to the conditions under 

 wnicn radiolarian-bearing sediments were deposited. ITew work on the 

 nS?i?^^=^i''i*^^°?v f?^^®^ sediments would add much needed data on the 

 intfrml heat "" ""^ radio-activity in the earth, hence of its 



.n.+.!'^®+ ""^ ^"""^ ^° ^^® coastal waters, and to the shelves of the 

 ^h?Hi^^?h^^^^T® J^^^^""*^ °^ ^^^^is ^^°^ *he land entirely over- 

 knnw?Z..ci i°+f shell-builders, geologists need a much more detailed 

 Knowledge of the sediments than it has yet been possible to attain. 

 Z^i-f.^^'^J'''^ wide_ regional variations in this zone are associated 



much of ""fhrSf r ^^ *^^ ''^^^''^ °^ ^^^ ^°^^^® ^°<=ks on land from which 

 ?^°, °!/5 .? ^^^^^1 °o^fs; this applied equally in the past. But 

 regional diiferences m tne turbulence of the water, and in the 

 onS^if'-S^ action of tides and currents are also important in this 



of ?hf rin?;.5f''^i^v\^^®y ■g°"'®''^ *^^ ^^S^^® °^ coarseness or fineness 

 °^ *^^ c^^etritus that can be held in suspension, thus sorting the sand 

 or mud regionally as it is laid down. & ^ ^ i^ 



whnc^.^^i!/"?"^® £^®i? ^^ °^ Sreat interest to the paleontologist, 

 Tm^.?.^ n^°^r ?° ^5^ conditions of depth, etc., Snder which ancient 

 r2^^io f-^^^^^^ i^^^^ is the nature of the rocks in which their 

 remains are lound. 



In shoal water, to meet the needs of the ffeoloeist a lara-e 



SS^p'Lf h'^^^'r °^ '^" ^"^^^^* ^^^* ^^ takef clole togetSef'(many 

 ?hP i5 1 "^^r^f^v^""^ ^^^^ than would suffice in the abyss) 4nd 

 lll,^^''^l^^,,^^1^^ be taken throughout the entire depth range of the 

 fj^i?^ in question; they must then be subjected to detailed analysis 

 '^*Sj.^^^°^f °7- Though this last requirement may seem self- 



?nowi Pd^P^'o/'^^ or"" r^ ^°'' ^^''^ ^^'^ localities, because our present 

 n^JifSJ shoal water sediments is based chiefly on the data given 

 JSadeau^p'SiiiT^ charts, which in turn, are dra^ from wholly^ 

 if^Si^ 5 ^^P^!^.°^ ^^s ^^en the bottom is described as "hardM 

 simply from the _ failure of the sounding lead to bring back any sample 

 at all. Geologically speaking, "hard" or "rocky" is a meaniniless 



s?rScv^'!?f; "^ ^°^ "!^n^^" '^ "^^ ^°"^ ^°°^ '^^^^^^^ ?ha?'?£\%'ad 

 soSdl.d -??S oJr''^'''^ ^T"^ ^^^^ ^y gl^^i^l ^^^i°^- ^ges ago, or 

 be obtL-aPd T^ '^"^^ '''''^^^? ^^ ^^^^* ^ fragment of the Material 

 a^ TJtl ni\J S °!^ ^ specific example, the nature of the bottom 

 iL^ritf ^i^e charts of the Gulf of KaiAe (one of the better 

 sounded seas), is of very little service to the geologist and even 

 TorMfTltl ^'^" <^ollected and analysed from loo siafion^ thtrl, 

 for this very purpose, it proved that serious gaps still remained. 



ir^ cylii obvious importance of accumulations of calcium carbonate 

 true Si^^ll'?;/^ l""^ formation of sedimentary rocks havl^?? is' 

 troSicIl S^d l^ili'^^^^^'T^ examination of several shoal areas in 

 AuqtiJfL ? eul>-tropical regions; of the reefs of Murray Island, 

 n? ;J! i?' ?2^ instance; of restricted localities around Samoa: ?nd 

 directed of^ar^P^'^t ^T^"" ^^^^"^- ^'^^^-^ attention has afsoS^en 

 thJsel wa?PT. ?^ ih! % '^•^''^°'P^^^^°^ °^ calcium carbonate from 

 tne sea water m the Tropics, whether by bacterial or by direct 



