ALBERT

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mineral aggregates which constitute one of the major types of rock encountered on the ocean floor; according to Menard (unpublished) about 10% of the pelagic area of the Pacific is covered by such nodules.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: Analyses are given for the core and outer colliform shell of a manganese nodule collected at a depth of 5000 m in the Indian Ocean, and for the red clay that encloses the nodules. Trace elements determined include rare earths, Nb, Ta, Th, and V. The cores of the nodules were once composed of basaltic rock, but now are phillipsite and nontronite. The outer shell is composed of manganite, with admixed quartz, phillipsite, and some geothite. The correlations established between the redox potentials and the concentration coefficients for 12 elements indicate that Eh plays a greater role in the formation of the manganiferous shells than coprecipitation properties.

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: 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: The cores described in this report were taken during the R/V Robert Conrad Cruise 02 from 26 until 28 January 1963 by the Lamont Geological Observatory, Columbia University. A total of 5 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Description: The cores described in this report were taken during the R/V Robert Conrad Cruise 05 from March until April 1963 by the Lamont Geological Observatory, Columbia University. A total of 13 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Description: The cores described in this report were taken during the R/V Robert Conrad Cruise 04 in March 1963 by the Lamont Geological Observatory, Columbia University. A total of 9 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Description: The cores described in this report were taken during the R/V Robert Conrad Cruise 06 from May until June 1963 by the Lamont Geological Observatory, Columbia University. A total of 5 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Description: The cores and dredges described in this report were taken during the Robert Conrad Cruise 7 from July until October 1963 by the Lamont Geological Observatory, Columbia University from the R/V Robert Conrad . A total of 29 cores and dredges were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.