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USGS1978

Marine geotechnical data for North Pacific sediments

Geotechnical data from the published and unpublished literature are compiled in SI units and tabulated in a standardized format. Eight data sets are presented from a geographic area approximately bounded by 5° and 32° north latitude and 120° and 170° west longitude. The data exist in machine-readable form in the data bank of the Marine Geotechnical Laboratory, Lehigh University. Individual geotechnical property data from cores collected from DOMES sites A, B, and C--including cores collected from the Deepsea Ventures mine site, are grouped and plotted against depth below the seafloor. A least-squares regression predictor equation for each grouped property related to depth is presented together with related statistical data for the equations. Low correlation coeficients for each of the predictor equations, except for "undisturbed" and remolded shear strength, suggest that improved predictor equations may result by grouping geotechnical data only for similar sediment types, rather than considering data from several large geographical areas grouped together without regard to differing sediment types within the areas. The objective of this investigation was to compile existing published, and unpublished marine geotechnical data in a standardized format, keypunched, and entered in the Marine Geotechnical Laboratory (MGL) data bank at Lehigh University. In addition, results of geotechnical analyses of DOMES and Deepsea Ventures cores performed in the MGL were synthesized by developing predictor equations for geotechnical properties of cores, related to a maximum depth below the seafloor of one meter, collected from DOMES sites A, B, and C, and from the Deepsea Ventures mine claim, which includes site C. Geotechnical property data from cores collected on DOMES cruises RP-6- 0C-75 and RP- 8-0C- 76 and from cores provided by Deepsea Ventures, Inc. are presented in separate chapters in this open file report. Data from eight other sources are tabulated in this report. They are from analyses of cores collected in an area of the deep seafloor approximately bounded by 5° and 32° north latitude and 120° and 170° west longitude. This large area includes pelagic clay, calcareous ooze, and siliceous ooze (Frazer et al., 1972). More specific sediment data, which are related to metal content of pelagic nodules for the area, are summarized by Hartmann et al., (1973). Keller and Bennett (1968) and Keller (1969) have reviewed the distribution of sediments, shear strength, water content, and bulk density for the entire North Pacific Ocean basin. These studies provide a regional review that is useful f or orientation before considering the geotechnical properties of the more limited area reported in this paper.

Open-File Report↗

USGS1977

Atlantic Margin Coring Project 1976: Preliminary Report on Shipboard and Some Laboratory Geotechnical data

This report presents reduced shipboard geotechnical data collected during the 1976 Atlantic Margin Coring Project; results of laboratory tests of specific gravity, water content, bulk density, and Atterberg limits; and sedimentation-compression e log p curves showing consolidation. A description of the procedures used at sea and in the laboratory and a short preliminary summary of the shipboard results also is included. The involvement of Marine Geotechnical Laboratory (MGL), Lehigh University, personnel in the 1976 Atlantic Margin Coring Project can be divided into two phases. In Phase One, the Lehigh nuclear-transmission densitometer was rebuilt to process cores at sea more rapidly than previously had been done in the laboratory, the equipment was assembled and tested aboard the Glomar Conception, and at-sea geotechnical measurements were made during the duration of the cruise. Data sheets were prepared for both unopened core sections (Appendix III) and split-core samples (Appendix IV). Completed data forms are on file at the MGL and at the Geological Survey in Woods Hole. Phase Two included reduction of the shipboard data, testing of all geotechnical samples taken from cores split aboard the ship, and certain other analytical work ashore utilizing the geotechnical measurements. Water content and weight/volume bulk density tests were performed at the MGL. Specific gravity and Atterberg limit tests and certain calculations were performed by Geological Survey personnel at the Corpus Christi, Texas, laboratory. During Phase One, 37 unopened, 1.5-m-long core sections were selected by Lehigh personnel for subsequent static and dynamic triaxial and consolidation testing ashore. The disposition of these cores is controlled by Geological Survey Project personnel; they are not further discussed in this report. A depth convention has been adopted in this report for the convenience of labeling core sections and analyzing the data. Each 9.2-m-long (30 ft) core liner had a maximum penetration depth referenced to the water-sediment interface; these data are given in Hathaway, et al. (1976). Each 9.2-m-long core liner was cut into six or fewer sections, each 1.5 m (5 ft) in length, aboard the ship. To the maximum penetration depth, 0.2 m was subtracted to obtain the depth at the bottom of the first 1.5 m section above the core catcher. To obtain values at the bottom of the remaining 1.5 m sections, an additional 1.5 m was added for each section. The depth of the bottom of each core section was used for all values obtained using the nuclear densitometer. Tests within core sections and samples collected from core sections were assigned depths based on the location of the test or sample within the core section. It should be clearly recognized that all depths within a 9.2-m-long core are estimates of the true depth, which cannot be uniquely calculated because of the uncertainty of the relationship of sediment contained within the core liner to true in situ depths. This report is considered to be preliminary because the author has not had access to the final lithologic logs or paleontological results, upon which a more accurate description of geotechnical results could be based. It would be inappropriate to comment on geological hazards until this information is made available.

Atlantic Ocean↗