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Dolomitization and dedolomitization in the Senonian chalk of Northern Ireland

Published online by Cambridge University Press:  01 May 2009

M. J. Wolfe
M. J. Wolfe
Affiliation:
Exploration and Production Research Division, B.P. Research Centre, Sunbury-on-Thames, Middlesex
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Summary

A dolomite locality in the Senonian chalk at Mullaghcarton shows a sequence of fabric variations between the unconformity with the Trias and a discontinuity surface marking the top of the basal beds. The four main variations are (1) xenotopic dolomite at the base, (2) hypidiotopic dolomite with zoned crystals and a calcite sealed intercrystalline porosity, (3) zoned dolomite rhombs scattered in a microspar micrite matrix, and at the top (4) micrite with rhombohedral pores. The xenotopic fabric is interpreted as being due to distant source dolomitization and the hypidiotopic fabric with zoned crystals to local source dolomitization. The dedolomitization phenomena are related to the mechanisms of dolomitization; for distant source dolomitization the dedolomitization fabric mimics the dolomite fabric, whereas for local source dolomitization the dedolomite regenerates the pre-dolomitization fabric.

Type
Articles
Information
Geological Magazine , Volume 107 , Issue 1 , January 1970 , pp. 39 - 49
Copyright
Copyright © Cambridge University Press 1970

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References

REFERENCES

Bathurst, R. G. C. 1958. Diagenetic fabrics in some British Dinantian limestones. Lpool Manchr geol. J. 2, 11–36.CrossRefGoogle Scholar
Cayeux, L. 1935. Les Roches Sédimentaires de France; Roches Carbonatées. Masson, Paris, 447 p.Google Scholar
de Groot, K. 1967. Experimental dedolomitization. J. sedim. Petrol. 37, 1216–1220.CrossRefGoogle Scholar
Evamy, B. D. 1963. The application of a chemical staining technique to the study of dedolomitization. Sedimentology, 2, 164–170.CrossRefGoogle Scholar
Evamy, B. D. 1967. Dedolomitization and the development of rhombohedral pores in limestones. J. sedim. Petrol. 37, 1204–1215.CrossRefGoogle Scholar
Fairbridge, R. W. 1957. The dolomite question. In LeBlanc, R. J. & Breeding, J. G. (Eds.): Regional Aspects of Carbonate Deposition; Spec. Publs. Soc. econ. Palaeont. Miner., Tulsa, 5, 125–178.Google Scholar
Folk, R. L. 1965. Some aspects of recrystallization in ancient limestones. In Pray, L. C. & Murray, R. C. (Eds): Dolomitization and Limestone Diagenesis a Symposium: Spec. Publs. Soc. econ. Palaeont. Miner., Tulsa, 13, 14–48.Google Scholar
Friedman, G. M. 1965. Terminology of crystallization textures and fabrics in sedimentary rocks. J. sedim. Petrol. 35, 643–655.Google Scholar
Friedman, G. M. & Sanders, J. E. 1967. Origin and occurrence of dolostones. In Chilingar, G. V., Bissell, H. J., & Fairbridge, R. W. (Eds);Developments in Sedimentology. Elsevier, Amsterdam, 9A, 267–348.Google Scholar
Murray, R. C. 1960. Origin of porosity in carbonate rocks. J. sedim. Petrol. 30, 59–84.CrossRefGoogle Scholar
Murray, R. C. 1964. Preservation of primary structures and fabrics in dolomite. In Imbrie, J. & Newell, N. D. (Eds); Approaches to Paleoecology, Wiley, New York, 388–403.Google Scholar
Reid, R. E. H. 1958. Remarks on the Upper Cretaceous Hexactinellids of County Antrim. Ir. Nat. J. 12, 236–243.Google Scholar
Shearman, D. J., Khouri, J. & Taha, S. 1961. On the replacement of dolomite by calcite in some Mesozoic limestones from the French Jura. Proc. Geol. Ass. 72, 1–12.CrossRefGoogle Scholar
Weyl, P. K. 1960. Porosity through dolomitization: conservation of mass requirements. J. sedim. Petrol. 30, 85–90.Google Scholar
Wolfe, M. J. 1968. Lithification of a carbonate mud; Senonian Chalk in Northern Ireland. Sediment. Geology, 2, 263–290.CrossRefGoogle Scholar