ALBERT

Description: The concentrations of rare-earth elements (REE) have been measured in 31 ferromanganese nodules from the Pacific and Indian Oceans and vary by almost a factor of 5. Too few nodules have been analyzed to define possible regional trends. The shale-normalized patterns, however, permit division of nodules into two groups: those from depth greater than 3000–3500 m and those from less depth. The factors that determine this change in the relative concentration of REE may be related to the mineralogy of manganese phases and/or the transport of REE to the deep ocean by particulate matter. Comparison of the REE patterns of nodules with those of phillipsite, phosphorite, clays, CaCO3 and seawater suggests that the patterns of these phases reflect fractionation from an initial pattern closely resembling that of shale. By assuming that the accumulation rate of REE in clays, CaCO3 and nodules is represented by that for surface sediments, it has been possible to estimate an accumulation rate of phillipsite in pelagic sediments of the Pacific of 0.02 mg/cm2/yr.

Description: A cruise, aboard the R/V Moana Wave was held during April-May 1974 and investigated an area 1,400 km S.S.E. of Honolulu, Hawaii, designated as DOMES site 'A' by a panel consisting of industry, government and academic representatives managing the Deep Ocean Mining Environmental Study (DOMES) under the coordination of NOAA Environmental Research Laboratory (ERL). This investigation was conducted in order to understand the effects of commercial ferromanganese mining on the oceanic environment. Baseline studies were made on the water column and ocean floor in typical areas prior to a possible full-scale mining operations in the area of the Pacific Occean stiruated between the Clarion and Clipperton fracture zones.

Description: The observations described in this report were made during the NAGA Expedition, Phase 1 between San Diego and Honolulu in June 1959 by Scripps Institution of Oceanography from, the R/V Stanger. Cores, bottom photographs and dredges are available at Scripps for sampling and study.

Description: In an earlier paper by two of the authors the conclusion was reached that the 33 recognized species of oxides of Mn could be separated into 3 groups: 1) those which appeared to be persistently supergene in origin, 2) those which appeared to be persistently hypogene, and 3) those which were supergene in some localities and hypogene in other localities. When that paper was written, there were available about 250 X-ray diffraction analyses of mineral specimens, also 35 complete and about 150 partial chemical analyses. The conclusions of that paper were based upon the interpretation of the geologic conditions under which these specimens occurred. Late in the preparation of that paper, it seemed worthwhile to make numerous semiquantitative analyses of specimens, largely from 9 western [U.S.A] states, selected carefully from 5 groups of geologic environments, in the hope that the frequency and percentages of some elements might be distinctive of the several geologic groups. For this purpose, 95 specimens were selected from the 5 groups, as follows: 19 specimens interpreted as supergene oxides by the geologists who collected them, 35 specimens of hypogene vein oxides, 22 specimens of Mn-bearing hot spring aprons, 9 specimens of stratified oxides, and 10 specimens of deep-sea nodules. The spectrographic analyses here recorded indicate that a group of elements - W, Ba, Sr, Be, As, Sb, Tl, and Ge - are present more commonly, and largely in higher percentages, in the hypogene oxide than in the supergene oxides and thus serve to indicate different sources of the Mn. Also, the frequency and percentages of some of these elements indicate a genetic relation of the manganese oxides in hypogene veins, hot spring aprons, and stratified deposits. The analyses indicate a declining percentage of some elements from depth to the surface in these 3 related groups and increasing percentages of some other elements. It is concluded that some of the elements in deep-sea nodules indicate that sources other than rocks decomposed on the continents, probably vulcanism on the floors of the seas, have contributed to their formation.

Description: Attempts to classify pelagic sediments have been based either on appearance and composition, or on the ultimate origin of the components. In particular it appears feasible to distinguish minerals which crystallized in sea-water from those which formed in magmas, in hydrothermal solution, or by weathering under acidic conditions. It is the case of iron and manganese oxide mineral aggregates which constitute one of the major types of rock encountered on the ocean floor; according to Menard (unpublished) about 10% of the pelagic area of the Pacific is covered by such nodules. The nodules consist of intimately intergrown crystallites of different minerals among those identified, besides detrital minerals and organic matter, are opal, goethite, rutile, anatase, barite, nontronite, and at least three manganese oxide minerals of major importance. Arrhenius and Korkisch (1959) have attempted to separate from each other the different minerals constituting the nodules, in order to establish the details of their structure and the localization of the heavy metal ions. The results demonstrate (Table II) that copper and nickel are concentrated in the manganese oxide phases concentrated in the reducible fraction. Cobalt, part of the nickel and most of the chromium are distributed between these and the acid-soluble group of the non-manganese minerals, dominated by goethite and disordered FeOOH.

Description: The origin of authigenic minerals on the ocean floor has been extensively discussed in the past with emphasis on two major processes; precipitation from solutions originating from submarine eruptions, and slow precipitation from sea water of dissolved elements, originating from weathering of continental rocks. It is concluded that in several marine authigenic mineral systems these processes overlap. A diagnostic principle is suggested, permitting a qualitative or semiquantitative discrimination between marine authigenic minerals crystallized from dissolved species, which have spent a long time in solution on the one hand, and the same minerals generated from solutions, near their source on the other. Extensive data are available for the manganese and iron oxide minerals forming manganese nodules. It is indicated on the basis of their composition and structure that many of the nodules found in the vicinity of the continents are made up essentially of manganese derived from continental weathering. In contrast to this group, all of the nodules found in the Pacific area of submarine vulcanism display the criteria for rapid precipitation near the source of solution. The distribution of barium minerals over the deep ocean floor is discussed.The same diagnostic principle is suggested for application to these solids, in order to discriminate between baryte and harmotome crystallized near the source of barium- rich, acidic vulcanites, and the same minerals formed from continental solution with passage through the biosphere. In the case of the authigenic aluminosilicates it is found that many of the framework elements (Si and particularly Al) have low passage time through solution, and the major fraction of these elements is consequently removed from solution in the vicinity of the eruptive source materials. Extensive modification of the crystal structures, however, takes place over long periods of time, adding particularly cations from sea water, and probably to some extent silica from siliceous fossils, which on their decay on the ocean floor appear to contribute to the silicate framework of growing zeolites. The marked fractionation of the rare earth ions between coexisting phases is pointed out, with discussion of the potential use of this phenomenon to indicate the processes of formation. The use of the hafnium/zirconium ratio as a tracer for the igneous source type is suggested, and the application of ideally imperfect tracers to establish the varying relative importance of volcanic versus halmeic source of marine minerals is discussed in general.

Description: Cruise MN-74-01 of the R/V Moana Wave was the first part of the field work of the NSF-IDOE Inter-University Ferromanganese Research Program in 1974. This program was designed to investigate the origin, growth, and distribution of copper/nickel-rich manganese nodules in the Pacific Ocean. The field effort was designed to satisfy sample requirements of the 15 principal investigators, while increasing general knowledge of the copper/nickel-rich nodule deposits of the equatorial Pacific. This report is the first of a series of cruise reports designed to assist sample requests for documented nodules, sediment, and water samples so the laboratory results can be realistically compared and related to the environment of nodule growth.

Description: A 0.25 m**2 United States Naval Electronics Laboratory box corer was used to take replicate samples from an oligotrophic bottom under the North Pacific Central Water Mass (~28°N, 155°W). The bottom is a red clay with manganese nodules at a depth of 5500-5800 m. Macrofaunal density ranges from 84 to 160 individuals per m**2 and is therefore much the same as in Northwest Atlantic Gyre waters. Of the macrofaunal taxa, polychaetes dominate (55 %), followed by tanaids (18 %), bivalves (7 %), and isopods (6 %). Meiofaunal taxa were only partially retained by the 297 µm screen used in washing. Even then, they are 1.5-3.9 times as abundant as the macrofaunal taxa, with nematodes being numerically dominant by far. Foraminifera seem to comprise an important portion of the community, but could not be assessed accurately because of the inability to discriminate living and dead tests. Remains of what are probably xenophyophoridans are also very important, but offer the same problem. Faunal diversity is extremely high, with deposit feeders comprising the overwhelming majority. Most species are rare, being encountered only once. The distributions of only three species show any significant deviation from randomness. The polychaete fauna from box cores collected from 90 miles to the north was not significantly different from that of the principal study locality. Concordance appeared at several taxonomic levels, from species through macrofaunal/meiofaunal relationships. As a result, the variation in total animal abundance shows aggregation among cores. We discuss Sokolova's concept of a deep-sea oligotrophic zone dominated by suspension feeders, and reconcile it with our present findings. The high diversity of the fauna combined with the low food level contradict theories that relate diversity directly with productivity.

Description: The cruise 9 of the R/V Valdivia was held from the 11 August 1974 to the 5 December 1974 as a survey expedition of the manganese nodule fields situated in the Pacific Ocean between the Clarion and Clipperton fracture zones. It was part of international effort coordinated by the International Decade of Ocean Exploration (IDOE) of the U.S. National Science Foundation (NSF). The stations details were stored in the SIO Ferromanganese Nodule - IDOE Portion ( http://www.ngdc.noaa.gov/docucomp/page?xml=NOAA/NESDIS/NGDC/MGG/Geology/iso/xml/G00250.xml&view=getDataView&header=none)