Factors influencing the pore volume of fine-grained sediments under low-to-moderate overburden loads

An anomalous increase of pore volume with increasing depth in the range 0—1,900 ft. occurs in fine‐grained sediments along the east side of the San Joaquin Valley of Cali‐ fornia. Several possible causes for the anomaly were inferred from a literature search and from study of the core samples. Statistical analyses of the core sample data suggest the principle causes to be variations in particle size, the diatom‐skeleton content, and the type of exchangeable cation adsorbed by the clay‐mineral constituents of the sediments.