Sites 679, 680, and 681 of the Ocean Drilling Program were drilled along an east-west transect across an organic-rich, diatomaceous, coastal upwelling facies that occurs as a shelf/slope lens along the Peru continental margin. Seven 60-cm-long, unsplit core sections from these sites were tested for consolidation, triaxial shear strength, and geotechnical index properties. The testing showed that the sediment has unusually high water content, Atterberg limits, degree of overconsolidation, compressibility, and shear strength. The sediment has unusually low density and grain specific gravity. Atterberg limits, grain specific gravity, compressibility, and apparent excess maximum past stress increase linearly with organic-carbon content, which also correlates positively with diatom content. Overconsolidation measured in these tests is probably not a result of sediment erosion or slumping, but rather the result of diagenesis or interparticle bonding by organic matter. High shear strengths were measured throughout, but particularly high relative shear strengths (as indicated by friction angles and degrees of dilatancy during shear) occur near 20 mbsf. This "crustlike" behavior is probably produced by early diagenesis (perhaps including dolotomization) within the upper 20 m, and is complemented by interlocking of diatoms.

The Hewitt realcompactification vX of a completely regular Hausdorff space X has been widely investigated since its introduction by Hewitt [17]. An important open question in the theory concerns when the equality v(X × Y) = vX × vY is valid. Glicksberg [10] settled the analogous question in the parallel theory of Stone-Čech compactifications: for infinite spaces X and Y, β(X × Y) = βX × β Y if and only if the product X × Y is pseudocompact. Work of others, notably Comfort [3; 4] and Hager [13], makes it seem likely that Glicksberg's theorem has no equally specific analogue for v(X × Y) = vX × vY. In the absence of such a general result, particular instances may tend to be attacked by ad hoc techniques resulting in much duplication of effort.

No abstract

No abstract