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On the Occurrence of Sulphur in Marine Muds and Nodules, and its bearing on their Mode of Formation

Published online by Cambridge University Press:  15 September 2014

J. Y. Buchanan Esq.
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Extract

In the first section of the cruise of the “Challenger,” that from Tenerife to Sombrero, the existence was established of deep-sea muds, perfectly free from carbonate of lime, consisting mainly of silicates mixed with ochreous material, principally hydrated oxides of iron and manganese, and of local concentrations of these materials in the form of nodules and of coatings or incrustations on dead calcareous matter. The qualitative composition of these concentrations was carefully determined, and it was particularly noted that whether in the form of nodules or of incrustations they were aggregations of the general materials of the bottom, and not concretions or coatings of pure hydrous oxides.

Type
Proceedings
Information
Proceedings of the Royal Society of Edinburgh , Volume 18 , 1892 , pp. 17 - 39
Copyright
Copyright © Royal Society of Edinburgh 1891

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References

page 17 note * They are described in my report, Proc. Hoy. Soc., 1876, vol. xxiv. p. 606.Google Scholar

page 18 note * The body of this worm was tested and found free from manganese.

page 19 note * Nature, 1878, vol. xviii. p. 628.Google Scholar

page 20 note * From deck-book of Steam Yacht “Mallard,” 1879.Google Scholar

page 20 note † Later, in the year 1886, when in charge of the expedition to survey the Gulf of Guinea in the steamship “Buccaneer,” I found the same thing practically universal all along the African coast, and developed in a most remarkable manner on the coast flat within a considerable radius of the mouth of the river Congo. Here it was necessary to introduce a new designation for muds, and in this district the most frequent entries in the deck-book as to the nature of the bottom are “cop. m.,” meaning coprolitic mud. These so-called coprolites were almost jet black and of the size of mice droppings, and they were covered with the same substance in flocculent form, or were free from it, according to the scour of the tide in the locality. It was best developed in comparatively shallow water, and more especially in a depth of 50 fathoms, when the large ash bucket, to the use of which as a dredge I found it convenient to revert, came up full of these coprolites, without any flocculent matter whatever. All along the coast the mud of the locality was moulded in a similar way, though it was not so striking. When the course of the cruise took us across the open ocean to Ascension, and thencenorthwards, we were able to trace the transition of the more earthy shore coprolites into the more mineralised and glauconitic pelagic ones.

page 22 note * A condensed account of my views of the part played by the sulphates of the sea water in the production of the ochreous deposits on the bottom of the ocean, and of the carbonate of lime of the shells of the Mollusca, is published in the Reports of the British Association (York), 1881, p. 584.Google ScholarPubMed

page 22 note † Bischof, , Lehrbuch der Chemischen und Physikalischen Geologie (1863), i. 81, 358.Google Scholar

page 22 note ‡ Daubrée, Geologie Experimentale, i. 268.