Samples for the compaction experiments were collected as whole-round, 6-cm-long core sections sampled shortly after core recovery. Sedimentological descriptions of the sampled core sections are given in Table 1. The samples were kept in capped pieces of liner to avoid damage and change of shape. The liners were sealed in wax to avoid drying. The samples were stored in a refrigerator on board ship and again in a refrigerator after being hand carried to the laboratory. Samples for the experiments were cut using a steel pipe in the soft ooze, whereas samples from the more indurated sediments were drilled out of the core sections into vertical cylinders, 2.5 cm in diameter and 5 cm in length. The samples were kept in a closed humid box in a refrigerator, and the experiments were run within a week after cutting or drilling the samples.
All tests were uniaxially confined and conducted in a stainless-steel compaction cell (Lind, 1993a) with constant rate of strain (1-3.5 10-6 s-1; Table 2) and one-sided parallel draining. The cell was equipped with a fluid pressure monitoring system, and the pore pressure was measured at the undrained end to ensure that the strain rate was low enough to prevent pore pressure build up. Two external, linear voltage deformation transducers were used. All experiments were done at room temperature. The loading was conducted to a maximal uniaxial effective stress of 10-42 MPa and a maximal uniaxial strain of 4%-42% (Table 2) and subsequently unloaded. Because sample disturbance was considered to be small, no strategy (e.g., repeated loading and unloading) was followed to overcome bedding. The unloading curve describing the final part of each test was only fully recorded for two samples because of software failure.
After the tests, the samples were carefully removed from the compaction cell, and the final unloaded strain was measured by a caliper. From each strained sample, a vertically oriented thin section was prepared from one half of the cylinder and described (Table 1; Pl. 1, Pl 2). The other half was used for physical and chemical characterization (Table 3). The specific surface was measured by nitrogen adsorption according to the Brunauer, Emmett, and Teller (BET) method (see Brunauer et al., 1938) using a Micromeritics Gemini 2375. Multipoint as well as single-point data were recorded. The material was disintegrated by a treatment with sodium pyrophosphate, and the grain-size distribution was determined using a Micromeritics SediGraph 5100. The insoluble residue was measured after treatment with diluted hydrochloric acid. BET data were also recorded for the samples from Site 807 used for compaction experiments by Lind (1993a) (Table 4).