181108a0Nature1814602195801111081090028-0836195810.1038/181108a0ukNatureNatureNATUREnatureNature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public./nature/journal/v181/n4602issueJournal homeArchiveCurrent issueAdvance online publicationPrivacy policySubscribeNature Publishing GroupCurrent issue181108a0Manganese Deposition and Deep Water Movements in the Caribbean
AU  - WANGERSKY, PETER J.
AU  - HUTCHINSON, G. E.Department of Zoology and Bingham Oceanographic Laboratory, Yale University, New Haven, Conn. Sept. 30.IN the course of a study of the chemical composition of certain deep-sea cores, particular attention has been paid to one such core (A 179-4) collected south-west of Hispaniola in 2,965 m. at lat. 16[deg] 36[prime] N., long. 74[deg] 48[prime] W. in the Caribbean and subjected by Emiliani1 to oxygen-18: oxygen-16 palaeothermometry.The material of this core is predominantly calcium carbonate with varying quantities of lithogenous sediment. There is no correlation between variations in either calcium or the major lithogenous constituents (silica, iron, aluminium, titanium) and temperature. The major lithogenous constituents exhibit variations highly correlated inter se, though there seems to be a slight systematic rise in titanium relative to the other constituents throughout the period of deposition of the sediment, which embraces, on Emiliani's interpretation, most of the Pleistocene.
The manganese content, however, is entirely unrelated to the lithogenous group of constituents or to calcium. Inspection of the graph (Fig. 1) indicates that manganese is inversely, if somewhat irregularly, related to surface temperature. The correlation coefficient of manganese on temperature, namely, 0-511, is, in fact, highly significant (with 35 pairs of observations, P~0-001).
Since manganese is the only abundant constituent likely to be sedimented by purely chemical process in the Atlantic Ocean or adjacent seas, its independent behaviour is not surprising; but the nature of its distribution raises the question as to why it should tend to precipitate at this station more rapidly during glacial than during interglacial periods.
We believe that the best explanation is to be found in Goldberg's2 hypothesis that colloidal manganese dioxide is deposited electrophoretically in regions of potential gradient set up as water containing charged particles moves through the Earth's magnetic field. The rate of deposition will clearly depend on the velocity and direction of the current. We consider, therefore, that the enhanced deposition of manganese in this part of the Caribbean during glacial periods is probably due to enhanced water movements related somewhat irregularly to glaciation. The most reasonable type of movement would presumably be the spilling of cold water over the rim of the Caribbean basin. Non-steady state movements of this type are becoming recognized3 as features of deep water circulation in various parts of the Atlantic. If our hypothesis proves reasonable, variation in manganese content in deep water sediments should throw considerable light on the incidence of such movements throughout the Pleistocene and possibly during more remote periods of the history of the ocean.
We are indebted to Prof. Maurice Ewing and to Dr. David B. Ericson of the Lamont Laboratory, Columbia University, and to Dr. Cesare Emiliani of the Marine Laboratory, University of Miami, for the opportunity to study this material. The work was supported by contract from the Office of Naval Research. A detailed report on the analyses will be published by one of us (P. J. W.) later.Emiliani, , C., J. Geol., 63, 538 (1955): cf. Ericson, , D. B., and Wollin, , G., Micropaleontol., 2, 257 (1956); Emiliani, , C., Science, 125, 383 (1957).ISIChemPortGoldberg, , E., J. Geol., 62, 249 (1954).ISIChemPortCooper, , L. H. N., J. Mar. Res., 14, 347 (1955). Dietrich, , G., Dtsch. Hydrogr. Z., 9, 78 (1956).ISI