Annotated record of the detailed examination of Mn deposits from the TRIPOD Expedition stations

The cores and dredges described in this report were taken on the TRIPOD Expedition from November until December 1966 by the Scripps Institution of Oceanography from the R/V Argo. A total of 38 cores and dredges were recovered and are available at Scripps for sampling and study.

Annotated record of the detailed examination of Mn deposits from R/V Caryn Cruise 10 stations

The cores described are taken during the R/V Caryn Cruise 10 in July 1949 by the Woods Hole Oceanographic Institution. A total of 14 cores were recovered and are available at Woods Hole Oceanographic Institution for sampling and study.

Annotated record of the detailed examination of Mn deposits from R/V Atlantis Cruise 158 stations

The cores described are taken during the R/V Atlantis Cruise 158 from September until October 1949 by the Woods Hole Oceanographic Institution. A total of 5 cores were recovered and are available at Woods Hole Oceanographic Institution for sampling and study.

Annotated record of the detailed examination of Mn deposits from USS San Pablo Cruise 3 stations

The cores described are taken during the USS San Pablo Cruise 3 from July to August 1949 by the Scripps Institute of Oceanography. A total of 49 cores were recovered and are available at Scripps Institute of Oceanography for sampling and study.

Observations and rare earth element composition of manganese nodules during Atlantis cruise AT266, Blake Plateau

An area of about 22,000 km² on the northern Blake Plateau, off the coast of South Carolina, contains an estimated 2 billion metric tons of phosphorite concretions, and about 1.2 billion metric tons of mixed ferromanganese-phosphorite pavement. Other offshore phosphorites occur between the Blake Plateau and known continental deposits, buried under variable thicknesses of sediments. The phosphorite resembles other marine phosphorites in composition, consisting primarily of carbonate-fluorapatite, some calcite, minor quartz and other minerals. The apatite is optically pseudo-isotropic and contains about 6% [CO3]**2- replacing [PO4]**3- in its structure. JOIDES drillings and other evidence show that the phosphorite is a lag deposit derived from Miocene strata correlatable with phosphatic Middle Tertiary sediments on the continent. It has undergone variable cycles of erosion, reworking, partial dissolution and reprecipitation. Its present form varies from phosphatized carbonate debris, loose pellets, and pebbles, to continuous pavements, plates, and conglomeratic boulders weighing hundreds of kilograms. No primary phosphatization is currently taking place on the Blake Plateau. The primary phosphate-depositing environment involved reducing conditions and required at least temporary absence of the powerful Gulf Stream current that now sweeps the bottom of the Blake Plateau and has eroded away the bulk of the Hawthorne-equivalent sediments with which the phosphorites were once associated.

Annotated record of the detailed examination of Mn deposits recovered by the Geological Survey of Japan (GSJ) during the 1971-1974 period in the Pacific Ocean

In 1974, the Geological Survey of Japan began its systematic investigation of manganese nodules in the Central Pacific Basin on the new geological research vessel Hakurei Maru. The first cruise (GH 74-5) was carried out over an eastern part area of the Basin (6°-10°30'N, 164°30'-171°30'W), and the authors report here the preliminary results on the occurrence of manganese nodule deposits, paying particular consideration to their relationship to submarine topography and surficial and sub-bottom sedimentary facies. The surveyed area comprises a deep-sea basin at 5,000-5,400 m, defined to the north and east by the chain of seamounts and guyots of the Christmas Ridge. The deep-sea basin is divided roughly into 2 contrasting topographic features. The eastern part is characterised by flattened topography resulting from continuous deposition of turbidities; the meridian and western parts are characterised by gently rolling topography and the existence of a large number of deep-sea hills. Manganese nodules are almost lacking in the former flattened eastern area, whereas they are widely distributed in the latter rolling meridian and western parts. The population density of nodules varies from less than 1 Kg/m² to 26 kg/m² and the higher density is found in the siliceous-calcareous ooze zone of rather small, flat basins surrounded by deep-sea hills. The density is closely related to the thickness of the transparent layer obtained by 3.5 kHz PDR profiling over the whole area. Considering the various data of grab sampling, 3.5 kHz PDR profiling and to a lesser extent of deep-sea television and camera observations, the most promising manganese field in the present area seems to be confined to the north of the western sector of the area.

Annotated record of the detailed examination of Mn deposits from R/V Atlantis Cruise 260 stations

The cores described here were taken during the R/V Atlantis Cruise 260 from October until November 1960 by the Woods Hole Oceanographic Institution at the Muir Seamount. A total of 27 cores and dredges were recovered and are available at Woods Hole Oceanographic Institution for sampling and study.

Annotated record of the detailed examination of Mn deposits from the Snellius II - Cruise 4 stations in the vicinity of the island of Misool, Eastern Indonesia

The chemical analyses of ferromanganese encrustations found on the seabed west of Misool, eastern Indonesia, indicate that these deposits formed in a way different from that of world-wide occurring manganese nodules. Ferromanganese coated pebbles and fragments that were found in the deeper parts of the study area probably originate from nearby ridges. The ferromanganese crust on the upper part of a dolomite fragment of ?30 kg is likely to be formed by hydrogenous processes, whereas that from the lower part seems to be formed by diagenetic processes mainly. These assumptions are supported by pore-water data from two box cores taken in the same area. The manganese and iron profiles versus depth in these cores indicate a high flux of these metals to the uppermost sediment layer, and possibly into the overlying bottom water. Factor analysis for the principal components of the microprobe analytical results of the mainly hydrogenous ferromanganese crust demonstrates a strong correlation of manganese with the trace metals, of iron with phosphorus and an antipathetic relationship between iron and manganese. Similar results have also been reported for abyssal manganese nodules in the world oceans. Factor analysis for the principal components of the analytical data obtained for the diagenetic ferromanganese crust results in a clear dolomite (Ca/Mg) dilution factor only.

Annotated record of the detailed examination of Mn deposits from SEVENTOW (7TOW) Expedition stations

The cores described in this report were taken on the SEVENTOW Expedition in February-September 1970 by the Scripps Institution of Oceanography from the R/V Thomas Washington. A total of 193 cores and dredges were recovered and are available at Scripps for sampling and study.