Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-25T19:10:16.431Z Has data issue: false hasContentIssue false

Mineralogy, chemistry, and origin of a concretionary siderite sheet (clay-ironstone band) in the Westphalian of Yorkshire

Published online by Cambridge University Press:  05 July 2018

C. D. Curtis
Affiliation:
Department of Geology, The University, Sheffield S1 3JD
M. J. Pearson
Affiliation:
Department of Geology and Mineralogy, Marischal College, Aberdeen AB9 1AS
V. A. Somogyi
Affiliation:
Department of Geology, The University, Sheffield S1 3JD

Summary

Concretionary siderite horizons are quite common in massive clay sequences. One such horizon, from the Westphalian of Yorkshire, has been studied in detail. Two iron-rich carbonate minerals occur together although they cannot be distinguished in thin section on account of very fine grain size. One is much richer in magnesium (pistomesite) than the other (siderite). The latter is rela-tively rich in manganese and the heavier stable carbon isotope 13C whereas the former carbonate is richer in calcium and 12C. The most important iron source is thought to have been hydrated iron oxides originating in soils. Much of the carbonate carbon started as organic molecules. The siderite appears to have formed earlier than the pistomesite. The stratiform character of these deposits appears to reflect siltier horizons in the mudstones, which presumably channelled pore water migration during compaction. This is probably why such carbonate horizons were formerly believed to be of simple sedimentary rather than diagenetic origin.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1975

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Brown, (G.), 1961. The X-ray identification and crystal structures of clay minerals. Mineralogical Society, London.Google Scholar
Curtis, (C. D.) and Svears, (D. A.), 1968. The formation of sedimentary iron minerals. Econ. Geol. 63, 257.CrossRefGoogle Scholar
Curtis, (C. D.) Petrowski, (C.), and Oertel, (G.), 1972. Stable carbon isotope ratios within carbonate concretions: a clue to place and time of formation. Nature, 235, 98.CrossRefGoogle Scholar
Deer, (W. A.), Howie, (R. A.), and Zussman, (J.), 1962. Rock forming minerals, 5, 273. Longmans.Google Scholar
Drever, (J. I.), 1971a. Magnesium-iron replacement in clay minerals in anoxic marine sediments. Science, 172, 1334.CrossRefGoogle Scholar
Drever, (J. I.), 1971b. Chemical weathering in a subtropical igneous terrain, Rio Ameca, Mexico. Journ. Sediment. Petrol. 41, 951.Google Scholar
Drever, (J. I.), 1971c. Early diagenesis of clay minerals, Rio Ameca Basin, Mexico. Ibid. 41, 982.CrossRefGoogle Scholar
Galimov, (E. M.) and Girin, (Yu. P), 1968. Variation in the isotopic composition of carbon during the formation of carbonate concretions. Geokhimiya, 2, 228.Google Scholar
Hallam, (A.), 1967. Siderite- and calcite-bearing concretionary nodules in the Lias of Yorkshire. Geol. Mag. 104, 222.CrossRefGoogle Scholar
Murata, (K. J.), Friedman, (I.), and Cremer, (M.), 1972. Geochemistry of diagenetic dolomites in Miocene marine formations of California and Oregon. U.S. Geol. Surv. Prof. Paper, 724C.CrossRefGoogle Scholar
Oertel, (G.) and Curtis, (C. D.), 1972. Clay-ironstone concretion preserving fabrics due to progress sive compaction. Geol. Soc. America Bull. 83, 2597.CrossRefGoogle Scholar
Pearson, (M. J.), 1973. The geochemistry of a Westphalian sediment sequence. Unpublished Ph.D. thesis, University of Sheffield. Google Scholar
Pearson, (M. J.), 1974a. Sideritic concretions from the Westphalian of Yorkshire: a chemical investigation of the carbonate phase. Min. Mag. 39, 696.CrossRefGoogle Scholar
Pearson, (M. J.), 1974b. Magnesian siderite in carbonate Concretions from argillaceous sediments in the West phalian of Yorkshire. Min. Mag. 39, 700.CrossRefGoogle Scholar
Raiswell, (R.), 1971. The growth of Cambrian and Liassic concretions. Sedimentology, 17, 147.CrossRefGoogle Scholar
Russell, (K. L.), 1970. Geochemistry and halmyrolysis of clay minerals, Rio Ameca, Mexico. Geochimica Acta, 34, 893.CrossRefGoogle Scholar
Saas, (E.) and Kolodny, (Y.), 1972. Stable isotopes, chemistry and petrology of carbonate concretions (Mishash Formation, Israel). Chem. Geol. 10, 261.CrossRefGoogle Scholar
Waterman, (L. S.), Sayles, (F. L.) and Manheim, (F. T.), 1973. Interstitial water studies on small core samples. Kegs 16, 17 and 18. Initial Reports of the Deep Sea Drilling Project, 18, 1001.Google Scholar
[Zaritskiy, (P. V.)] Зaρицкий (П. B.) 1964. (Isomorphous entry of CaCO3 into siderite and magnesian siderite concretions of the Donbas). дoкʌ. aкaд. Hayк CCCρ (Compt. Rend. Acad. ScL URSS), 155, 1341.Google Scholar