average (derived) elastic properties and includes defining relationships. The 

 total compressibility (k ) is assumed to be derived from the porosity frac- 

 tional contribution of that for water and dry sediment (Hamilton, 1965). The 

 column headed "L" is for properties determined herein, and that headed "H" 

 corresponds to average continental terrace (North Pacific) properties deter- 

 mined by Hamilton (1971) . 



In general, the properties determined herein fit those described by Hamilton 

 (1971) for continental terrace materials, with the slightly higher moduli and 

 sound propagation speeds for the latter associated with the presence of rela- 

 tively coarser material (silty sand to sand) . The comparison is fair although 

 Hamilton does not report any investigations in carbonate sediments, but the 

 percent carbonate does not generally determine these elastic parameters unless 

 it is entirely in the form of oolitic shells (Greffard, 1969). In both studies 

 the shear wave sound speed is approximately 1/5 to 1/4 of the compress ional wave 

 sound speed and this is due entirely to the rather low rididity (G) of these 

 high porosity sediments. 



Correlation of In Situ and Laboratory Data 



Sound speed and laboratory properties were correlated at corresponding sediment 

 levels for all sites. A complete statement of this analysis is given in Lewis 

 (1971) . Figures 5-9 illustrate these correlations where the symbol "x" repre- 

 sents gravity corer data and "6" indicates DOSP sample data. Curves are labeled: 

 "L" = this report; "H" = Hamilton (1971); "C" = Cernock (1970); "F" = Faas (1969) 

 "M" = McLeroy (1968); and "K" = Kermabon (1968). (Units are given in Table 4.) 



Figure 5: Velocity versus Shear Strength 



Lj: Vc = 170.5(a/P)f + 4906 



Lj: V^ = 177.0(q^/P^) + 4915 



Subscripts 'f and 'o' refer to conditions at failure and at primary consolida- 

 tion respectively in the consolidated undrained triaxial shear strength test 

 (D 'Andrea, 1966). 



Figure 6: Porosity versus Density 



L: e = me - 49. 3p^ 



H: e = 156 - 57. Op^ 



C: e = 165 - 62.7pt 



Figure 7: Impedance versus Density 



L: Z = 1.615pt - 0.1146 



C: Z = 1.608pt - 0.153 



VII-27 



