Discussion — Atterberg limits were determined on a number of cores collected 

 from the continental borderland area off Southern California by Emery and his asso- 

 ciates (Emery and Rittenberg, 1952, p. 765; Emery and Terry, 1956, p. 276-277; and 

 Emery, 1960, p. 260-261). Reported values of water content in percent dry weight 

 always were higher than liquid limits in the surficial sediments, although the reverse 

 often occurred at depths greater than several feet. Emery (1960, p. 260) concluded 

 that tops of the cores, where the water content is greater than the liquid limit, are 

 liquid although they may not be mobile. With respect to this statement, I wish to 

 emphasize that such sediments are "liquid" only in the remolded condition. In their 

 undisturbed, in-place condition they may possess considerable structural strength, 

 relative to their remolded strength; as stated by Terzaghi (1955, p. 563): "the 

 strength of the sediment in situ at a water content equal to the liquid limit can 

 amount to several hundrecTgrams per square centimeter." At water contents about 

 equal to the liquid limit, found at some distance below the top of the cores tested in 

 the Hydrographic Office program, measured cohesion ranged from about 34 g/cm , 

 core A 23, to 234 g/cm^, core B 83^. With respect to the quantitative distinction 

 between solid and liquid, the reader is referred to a discussion by Reiner (1958, 

 p. 465-467, 542). 



It is noteworthy that the only instance where the surface to 5 cm water content 

 was less than the liquid limit is in core C 16, where surface desiccation following 

 core collection is shown by a measured 90.5 percent saturation (Appendix B) . 



An oft -repeated statement is that at the time of sedimentation water content 

 approximates liquid limit (for example, Terzaghi, 1927, p. 41; Jones, 1944, p. 145; 

 Skempton and Bishop, 1954, p. 433). On the other hand, Hough (1944, p. 1185) 

 reports that water content is well above liquid limit in St. Lawrence River clay. 

 Results of Emery and his associates and this paper show that the surficial sediments, 

 often down to depths of several meters, possess water contents appreciably higher than 

 the liquid limit. Occasionally, the liquid limit is exceeded by more than 80 percent- 

 age points (Emery, 1960, Fig. 211; this paper, core C 20). Not realizing the magni- 

 tude of this difference may lead to meaningless conclusions; for example, natural 

 water content of a sediment a few percent higher than the liquid limit constitutes 

 evidence that little desiccation has occurred between the time the core was collected 

 and the time tested (Sykes, 1960, p. 49). 



These values are appreciably greater than cohesion at the liquid limit reported by 

 Skempton and Bishop (1950, p. 99). 



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