Vane Shear Strength and Index Properties . Vane shear strengths 

 and index property data are plotted in Figure 3. Since only two sec- 

 tions were evaluated, no conclusive trends can be established. Although 

 the data suggest that both the remolded and original strengths increase 

 with depth, a greater increase would normally be expected. The high 

 water content or possible sample disturbance (L/D^30) may account for 

 the behavior. 



Station B 



Geologic Considerations . Station B is located between the Northwest 

 Christmas Island Ridge and the Marshall and Gilbert Islands. The depth 

 of water at the site exceeded 3,150 fathoms. A series of narrow throughs . 

 which reach depths as great as 1,000 fathoms below the surrounding area, 

 occur in the vicinity of the site (Fairbridge, 1966). Sediments at the 

 site are typically composed of fine-grained pelagic materials. 



Sediment Identification . The gravity corer obtained 235 centimeters 

 of homogeneous deep-sea red clay. A visual examination of the core 

 found no evidence of sample layering. The Unified Classification System 

 designates the soil as an inorganic silt of high to very high compres- 

 sibility (MH) , while the Trilinear Classification System considers the 

 material a silty clay. The median diameter of the particle distribution 

 is less than 0.002 millimeter. The percentages of clay, silt, and sand 

 size particles are 67, 22, and 11, respectively. Carbonate carbon and 

 organic carbon contents are less than 0.187o of the sample. 



Vane Shear Strength and Index Properties . Vane shear strengths 

 and index properties are plotted in Figure 4. The index properties 

 generally behave as expected (water content decreases with depth); 

 however, the original strength determination on the deepest increment 

 appears low. Since the length-to-diameter ratio exceeded 20, the incre- 

 ment may have been disturbed excessively during sampling. An increase 

 in water content for constant plasticity index tends to substantiate 

 this belief. 



Station C 



Geologic Considerations . Station C is located on the east side of 

 the Kermadic-Tonga Trench. The trench to the west virtually isolates 

 the site from sediments of terrigenous origin; therefore, sediment 

 conditions are similar to the average deep Pacific situation, where the 

 rate of deposition is slow and sediments are primarily pelagic in origin 

 (Raitt et al., 1955). Depth of water at the site is approximately 3,100 

 fathoms . 



Sediment Identification . The gravity corer obtained 209 centimeters 

 of homogeneous deep-sea red clay. A visual examination of the core found 



23 



