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X.—Frictional Fusion Along a Himalayan Thrust*

Published online by Cambridge University Press:  11 June 2012

J. S. Scott  and
H. I. Drever
J. S. Scott
Affiliation:
Department of Geology, University of St Andrews.
H. I. Drever
Affiliation:
Department of Geology, University of St Andrews.
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Synopsis

At a height of 4400 metres in the Nepal Himalaya, a vitreous and vesicular rock was discovered by J. S. Scott in 1949. It is located along a line of intense brecciation in a region of high-grade granitic gneisses.

This paper is based on a laboratory examination of a specimen of this rock and a few other specimens from the same locality. As some of these specimens have no exact counterpart hitherto described, a new but self-explanatory nomenclature has been employed in their description. The new rock-types—breccia with a cryptomylonite matrix, cryptomylonite and hyalomylonite—seem to represent, in this order, progressive stages in the degree of vitrifaction.

Biotite, alkali feldspars and quartz participated in the vitrifaction, which was due to high temperatures and heat developed by friction between these minerals in a triturated rock medium of low thermal conductivity.

An important function is attributed to the biotite which, in the more vitreous parts of the rocks, tends to disappear entirely. It is suggested that selective melting of this biotite has yielded to the liquid ferrous iron, and fluxing by this component is believed to be a critical factor although water must also be considered. Chemical analysis revealed no significant quantity of water in the glass-rich rock, but the development of vesicles and bubbles implies that there was more water in solution prior to its ebullition as a vapour phase.

There appears to have been a remarkable variation in temperatures within extremely short distances, and there is some evidence that the specific melting points of the alkali feldspars may, in a few exceptional instances, have been attained.

Type
Research Article
Information
Proceedings of the Royal Society of Edinburgh, Section B: Biological Sciences , Volume 65 , Issue 2 , 1954 , pp. 121 - 142
Copyright
Copyright © Royal Society of Edinburgh 1954

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Footnotes

*

This paper was assisted in publication by a grant from the Carnegie Trust for the Universities of Scotland.

References

References to Literature

Barth, T. F. W., 1952. Theoretical Petrology. John Wiley & Sons, Inc., New York and London.Google Scholar
Bateman, J. D., 1940. “An archean mylonite from Northwestern Ontario”, Amer.J. Sci., 238, 742–750.CrossRefGoogle Scholar
Bowden, F. P., 1947. “Friction”, Science News, 4, 139–166.Google Scholar
Bowden, F. P., and Tabor, D., 1950. The Friction and Lubrication of Solids. Int. Ser. of Monographs on Physics. Oxford University Press.Google Scholar
Bowen, N. L., and Aurousseau, M., 1923. “Fusion of sedimentary rocks in drill holes”, Bull. Geol. Soc. Amer., 34, 431–448.CrossRefGoogle Scholar
Bowen, N. L., and Schairer, J. F., 1932. “The system FeO-SiO2”, Amer.J. Sci., 24, 177–213.CrossRefGoogle Scholar
Bowen, N. L., 1938. “Crystallisation equilibrium in nepheline–albite–silica mixtures with fayalite”, J. Geol., 46, 397–411.CrossRefGoogle Scholar
Bowen, N. L., and Tuttle, O. F., 1950. “The system NaAlSi3O8–KAlSi3O8–H2O”, J. Geol., 58, 489–511.CrossRefGoogle Scholar
Chayes, F., 1952. “Notes on the staining of potash feldspar with sodium cobaltinitrite in thin section”, Amer. Min., 37, 337–340.Google Scholar
Day, A. L., and Allen, E. T., 1905. “The isomorphism and thermal properties of the feldspars. Pt. I. Thermal study”, Pubn. 31, Carnegie Institution of Washington.Google Scholar
Dry, A. L., 1925. “The volcanic activity and hot springs of Lassen Peak”, Pubn. 360, Carnegie Institution of Washington.Google Scholar
Dougal, J. W., 1928. “Observations on the geology of Lewis”, Trans. Edin. Geol. Soc., 12, Pt. I, 12–18.CrossRefGoogle Scholar
Gabriel, A., and Cox, E. P., 1929. “A staining method for the quantitative determination of certain rock minerals”, Amer. Min., 14, 290–292.Google Scholar
George, W. O., 1924. “The relation of the physical properties of natural glasses to their chemical composition”, J. Geol., 32, 353–372.CrossRefGoogle Scholar
Goldschmidt, V. M., 1911. “Petrographische Untersuchung einiger Eruptivgesteine von Nordwestspitzbergen”, Vid. Selsk. Skrifter, No. 9.Google Scholar
Goranson, R. W., 1931. “The solubility of water in granite magmas”, Amer. J. Sci., 22, 481–502.CrossRefGoogle Scholar
Goranson, R. W., 1932. “Some notes on the melting of granite”, Amer.J. Sci., 23, 227–236.Google Scholar
Greig, J. W., and Barth, T. F. W., 1938. “The system Na2O, Al2O3, 2SiO2 (Nephelite, Carnegieite)-Na2O, Al2O3, 6SiO2 (Albite)”, Amer.J. Sci., 35A, 93–112.Google Scholar
Hall, A. L., and Molengraaff, G. A. F., 1925. “The Vredefort mountainland in the Southern Transvaal and in the Northern Orange Free State”, Verh. der Koninklijke Akad. van Wetenschappen te Amsterdam, 24, No. 3.Google Scholar
Heinrich, E. W., 1946. “Studies in the mica group: the biotite-phlogopite Series”, Amer.J. Sci., 244, 836–848.CrossRefGoogle Scholar
Jeffreys, H., 1942. “On the mechanics of faulting”, Geol. Mag., 79, 291, 295.CrossRefGoogle Scholar
Jehu, T. J., and Craig, R. M., 1923. “Geology of the Outer Hebrides. Pt. I. The Barra Isles”, Trans. Roy. Soc. Edin., 53, 430–441.Google Scholar
Knopf, A., 1938. “Partial fusion of granodiorite by intrusive basalt, Owens valley, California”, Amer.J. Sci., 36, 373–376.Google Scholar
Kracek, F. C., 1942. “Melting and transformation temperatures of mineral and allied substances”, Geol. Soc. Amer., Special Paper, No. 36, sect, 11, 139–174.Google Scholar
Lapworth, C., 1885. “The Highland controversy in British geology; its causes, course and consequences”, Nature, 32, 558–559.Google Scholar
Larsen, E. S., and Switzer, G., 1939. “An obsidian-like rock formed from the melting of a granodiorite”, Amer.J. Sci., 237, 562–568.Google Scholar
Lloyd, P., 1950. “New British exploration in Nepal”, Geogr.J., 116, 172–180.CrossRefGoogle Scholar
Morey, G. W., 1938. The Properties of Glass. Monograph Series, Amer. Chem. Soc. Reinhold Pub. Co., New York.Google Scholar
Peach, B. N., and Horne, J., 1930. Chapters on the Geology of Scotland. Oxford University Press.Google Scholar
Shand, S. J., 1916. “The pseudotachylyte of Parijs (Orange Free State) and its relation to ‘trap-shotten gneiss’ and flinty crush-rock”, Quart. J. Geol. Soc., 72, 198–221.CrossRefGoogle Scholar
Shand, S. J., 1947. Eruptive Rocks. 3rd Ed. Murby & Co., London.Google Scholar
Shepherd, E. S., 1938. “The gases in rocks and some related problems”, Amer.J. Sci., 35A, 311–351.Google Scholar
Thomas, A. N., 1952. “On the origins of the Kumaon lakes in the Himalayas”, Geol. Mag., 89, 385–400.CrossRefGoogle Scholar
Waters, A. C., and Campbell, C. D., 1935. “Mylonites from the San Andreas fault zone”, Amer. J. Sci., 29, 473–503.Google Scholar
Willemse, J., 1938. “On the old granite of the Vredefort region and some of its associated rocks”, Trans. Geol. Soc. S. Africa, 40, 43–119.Google Scholar
Yoder, H. S. Jr., 1952. “The MgO–Al2O3–SiO2–H2O system and the related metamorphic facies”, Amer.J. Sci. (Bowen Volume), 569–627.Google Scholar