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Hercynian Fe-Mg Metasomatism in Cornwall: A Reinterpretation

Published online by Cambridge University Press:  01 May 2009

Doris L. Reynolds
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Extract

In connection with a recent investigation of the geochemical changes leading up to granitization, the writer (Reynolds, 1946) had occasion to plot the chemical analyses of the rocks of the Kenidjack and Botallack region, Cornwall (Tilley and Flett, 1930; Tilley, 1935) on a von Wolff diagram. Since the diagram required somewhat lengthy discussion, however, it was not included in the geochemical paper. The diagram is nevertheless of interest because it presents in a new form the problem of the genetic associations of these curious rocks, characterized as they are by anthophyllite, cummingtonite, cordierite, and grunerite, and provides useful hints which might form a basis for further field investigations in Cornwall. The present paper, offering tentative interpretations of some of the Cornish rocks, is written in the hope of focusing attention on the petrogenetic significance of this region, and thus of stimulating detailed investigations, with strict correlation between field observations and chemical analyses, by which means alone the problems presented can be solved.

Type
Articles
Information
Geological Magazine , Volume 84 , Issue 1 , February 1947 , pp. 33 - 50
Copyright
Copyright © Cambridge University Press 1947

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References

REFERENCES

Adams, F. D., 1909. On the origin of the amphibolites of the Laurentian area of Canada. Journ. Geol., 42, 1–18.CrossRefGoogle Scholar
Backlund, H. G., 1936. Der “Magmaaufstieg“ in Faltengebirgen. C.R. Soc. Géol, Finlande, no. 9, 293–347.Google Scholar
Backlund, H. G., 1936. Zur genetischen Deutung der Eklogite. Geol. Rund., 27, 47–61.CrossRefGoogle Scholar
Backlund, H. G., 1943. Einblicke in das geologische Geschehen des Präkambriums. Geol. Rund., 34, 79–148.CrossRefGoogle Scholar
Backlund, H. G., 1946. The granitization problem. Geol. Mag., 83, 105–117.CrossRefGoogle Scholar
Barrois, C., 1900. Sketch of the geology of central Brittany. Proc. Geol. Assoc., 41, 101–132.Google Scholar
Bugge, J. A. W., 1943. Geological and petrographical investigations in the Kongsberg-Bamble formation. Norges Geol. Undersök., no. 160, 1–150.Google Scholar
Cooke, H. C., 1927. Some chemical changes in rocks, caused by shearing. Geol. Surv. Canada. Bull. 46, 22–30.Google Scholar
Demay, A., 1934. Contribution à la synthèse de la chaîne Hercynienne d'Europe. Étude du plan axial de l'évolution et de l'orogénèse Hercynienne. Bull. Soc. Géol. France, 5 Sér., 4, 311–345.Google Scholar
Demay, A., 1936. Sur la tectonique profonde des chaînes de montagnes. Bull. Soc. Géol. France, 5 sén, 6, 165–180.Google Scholar
Demay, A., 1937. Quelques remarques sur les gneiss d'injection des Cévennes septentrionales, du Forez, du Rouerque et du Cantal. Bull. Soc. Géol. France, 5 sér., 7, 365–375.Google Scholar
Eskola, P., 1914. On the petrology of the Orijärvi region in south-western Finland. Bull. Comm. Géol. Finlande, no. 40, 1–274.Google Scholar
Greenly, E., 1903. The diffusion of granite into crystalline schists. Geol. Mag., 40, 207–212.CrossRefGoogle Scholar
Hendriks, E. M. Lind, 1937. Rock succession and structure in South Cornwall: a revision. Quart. Journ. Geol. Soc., 93, 322–367.CrossRefGoogle Scholar
Hendriks, E. M. Lind, 1939. The Start-Dodman-Lizard boundary-zone in relation to the Alpine structure of Cornwall. Geol. Mag., 76, 385–402.CrossRefGoogle Scholar
Kertorne, F. 1926. A propos de la session extraordinaire de la Société Géologique et MinéYalogique de Brétagne en Normandie. Bull. Soc. Géol. et Min. Brétagne, 7, 1927–1929, 138–140.Google Scholar
Magnusson, N. H., 1940. Ljusnarsbergs malmtrakt: berggrund och malmfyndigheter. Sver. Geol. Undersök., Ser. Ca, no. 30, 1–188.Google Scholar
Perrin, R., and Roubault, M., 1941. Observation d'un “front” de méta-morphisme régional. Bull. Soc. Géol. France, 5 sér, 11, 183–192.CrossRefGoogle Scholar
Phillips, F. C., 1928. Metamorphism in the Upper Devonian of N. Cornwall. Geol. Mag., 65, 541–556.CrossRefGoogle Scholar
Phillips, J. A., 1875. The rocks of the mining-districts of Cornwall, and their relation to metalliferous deposits. Quart. Journ. Geol. Soc., 31, 319–345.CrossRefGoogle Scholar
Phillips, J. A., 1876. On the so-called “greenstones” of Western Cornwall. Quart. Journ. Geol. Soc., 32, 155–179.CrossRefGoogle Scholar
Phillips, J. A., 1878. On the so-called “greenstones” of Central and Eastern Cornwall. Quart. Journ. Geol. Soc., 34, 471–497.CrossRefGoogle Scholar
Reynolds, , Doris, L., 1946. The sequence of geochemical changes leading to granitization. Quart. Journ. Geol. Soc., 102, 389–446.CrossRefGoogle Scholar
Scrivenor, J. B., 1938, 1939. On the geology of the Lizard peninsula. Geol. Mag., 75, 304–8, 385–394, 515–526; 76, 37–41, 97–109.CrossRefGoogle Scholar
Sundius, N., 1935. On the origin of late magmatic solutionsocontaining magnesia, iron, and silica. Sver. Geol. Undersök., Arsbok 29, no. 7, 1–24.Google Scholar
Tillev, C. E., 1923. The petrology of the metamorphosed rocks of the Start area, South Devon. Quart. Journ. Geol. Soc., 79, 172–204.CrossRefGoogle Scholar
Tillev, C. E., 1935. Metamorphism associated with the greenstone-hornfelses of Kenidjack and Botallack, Cornwall. Min. Mag., 24, 181–202.Google Scholar
Tillev, C. E., 1937. Anthophyllite-cordierite-granulites of the Lizard. Geol. Mag., 74, 300–9.CrossRefGoogle Scholar
Tillev, C. E., and Flett, J. S., 1930. Hornfelses from Kenidjack, Cornwall. Summ. of Progress Geol. Surv. for 1929, Part II, 24–41.Google Scholar
Wegmann, C. E., 1935. Zur Deutung der Migmatite. Geol. Rund., 26, 305–350.CrossRefGoogle Scholar
Wiseman, J. D. H., 1934. The central and south-west Highland epidiorites: a study in progressive metamorphism. Quart. Journ. Geol. Soc., 90, 354–417.CrossRefGoogle Scholar