Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-26T06:29:06.208Z Has data issue: false hasContentIssue false

Symplectite-bearing Nodules in the Ardgour Marble, Argyllshire

Published online by Cambridge University Press:  01 May 2009

H. I. Drever
Affiliation:
Department of Mineralogy and Petrology, Cambridge.

Summary and conclusions

The nodules examined have been shown to contain a variety of minerals and to exhibit certain mineralogical and structural differences from one another or within the nodules themselves. The mineralogical differences serve to separate five definite types of mineral facies. There are also described types transitional between the nodules themselves, and between them and the surrounding rock, grading from types sufficiently aluminous to exclude the formation of wollastonite to less aluminous types in which this mineral is formed.

Owing to insufficiently prolonged variations of the metamorphic conditions equilibrium has not been established, and a remarkable series of replacement structures has been left in the rock by means of which the course of several stages of its metamorphism has been established.

Lack of knowledge concerning the metamorphic conditions previous to changes due to the influence of the surrounding diorite, the isolated character of the nodules and the intricacy of the relationships between the minerals render the origin and metamorphism of these nodules subject to a variety of interpretations. The balance of evidence seems in favour of the one put forward here.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1936

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

REFERENCES

Bailey, E. B., and Maufe, H. B., (1916). “The Geology of Ben Nevis and Glencoe” (Explanation of Sheet 53), Mem. Geol. Survey of Scotland, p. 84.Google Scholar
Sederholm, J. J., (1916). “On Synantetic Minerals and Related Phenomena,” Bull. Comm. Géol. Finlande, No. 48.Google Scholar
Laitakari, A., (1921). “Petrographie und Mineralogie der Kalksteinlager-stätten von Parainen (Pargas),” Bull. Comm. Géol. Finlande, No. 54.Google Scholar
Eckermann, H. Von, (1922). “Rocks and Minerals of the Mansjö Mt.,” Géol. Fören. Stockholm Förhandl., lxiv, p. 330.Google Scholar
Eckermann, H. Von, (1923). “Rocks and Contact Minerals of Tennberg,” Géol. Fören. Stockholm Förhandl. xlv, p. 490.Google Scholar
Eskola, P., (1915). “On the Relations between the Chemical and Mineralogical Composition in the Metamorphic Rocks of the Orijärvi Region,” Bull. Comm. Géol. Finlande, No. 44, p. 144.Google Scholar
Eskola, P., (1922). “On Contact Phenomena between Gneiss and Limestone in Western Massachusetts,” Jour, of Geol., xxx, No. 4, p. 292.Google Scholar
Warren, B., and Bragg, W. L., (1929). “The Structure of Diopside, CaMg (Si03)2,” Zeits. für Krist., lxix, p. 168.Google Scholar
Machatschki, F., (1930). “Die Summenformel des Vesuvians und seine Beziehungen zum Granat,” Centralblatt für Mineralogie, p. 284.Google Scholar
Read, H. H., (1931). “The Geology of Central Sutherland,” Mem. Qeol. Surv. Scotland, p. 132.Google Scholar
Warren, B., and Modell, D. I., (1931). “The Structure of Vesuvianite, Ca10Al4(MgFe)2Si2O34(OH)4,” Zeits. für Krist., Ixxviii, p. 422.Google Scholar
Winchell, A. N., (1933). Elements of Optical Mineralogy, part ii, p. 278.Google Scholar