Abstract
Layering in which one or more of the component minerals has grown perpendicular to layer boundaries occurs, under a variety of names, in volcanic, hypabyssal nad plutonic igneous rocks. The most recent and best name is comb layering. The oriented minerals are elongate, are commonly branching and may be curved. Experimental crystallization of plagioclase and ternary feldspar melts confirms that a substantial degree of supercooling 01 a significant cooling rate is necessary to produce the curved or branching crystal morphologies typical of comb layering. The more viscous the melt, the less the supercooling required. Changes in the water content or confining pressure are mechanisms for inducing supersaturation in deep-seated magmas, that are consistent with field and experimental evidence. The change from modal dominance by a single elongate crystal phase in one comb layer to dominance by another phase in a contiguous comb layer is explained by the presence of constitutional supercooling ahead of the growing crystals of a given layer.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Barriere, M.: Le gabbro orbioulaire des Alharesses (massif de Neouvielle, Pyrenees francaises). Bull. Soc. Franc. Mineral. Crist. 95, 495–506 (1972)
Barriere, M., Chauris, L., Cotton, J.: Premieres donnees sur un facies orbiculaire dans le massif granitique de l'Aber-Ildut (Finistere, France). Bull. Soc. Franc. Mineral. Crist. 94, 402–410 (1971)
Bottinga, Y., Kudo, A., Weill, D.: Some observations on oscillatory zoning and crystallization of magmatic plagioclase. Am. Mineralogist 51, 792–806 (1966)
Bryan, W.B.: Morphology of quench crystals in submarine basalts. J. Geophys. Res. 77, 5812–5819 (1972)
Chalmers, B.: Principles of solidification. New York: John Wiley 1964
Dawson, J.B., Hawthorne, J.B.: Intrusion features of some hypabyssal South African Kimberlites. Bull. Volcanol. 34, 740–757 (1970)
Donaldson, C.H.: Olivine crystal types in harrisitic rocks of the Rhum pluton and Archaean spinifex rocks. Geol. Soc. Am. Bull. 85, 1721–1726 (1974)
Donaldson, C.H.: Calculated diffusion coefficients and the growth rate of olivine in basaltic magma (in press)
Drever, H.I., Johnston, R.: Crystal growth of forsteritic olivine in magmas and melts. Trans. Roy. Soc. Edinburgh 63, 289–315 (1957)
Drever, H.I., Johnston, R.: Metastable growth patterns in some terrestrial and lunar rocks. Meteoritics 7, 327–340 (1972)
Elsdon, R.: Crystallization history of the Upper Layered Series, Kap. Edvard Holm, East Greenland. J. Petrol. 12, 499–521 (1971)
Farquharson, R.B.: The petrology of late tertiary dolerite plugs in the South Cariboo Region, British Columbia. Can. J. Earth Sci. 10, 205–225 (1973)
Jahns, R.J., Burnham, C.W.: Experimental studies of pegmatite genesis: I. a model for the derivation and crystallization of granite pegmatites. Econ. Geol. 64, 843–864 (1969)
Jahns, R.J., Tuttle, O.F.: Layered pegmatite-aplite intrusives. Mineral. Soc. Am. Spec. Paper 1, 78–92 (1963)
Kadik, A.A., Khitarov, N.I.: Effect of pressure on the exchange of water between magma and the enclosing rocks. Geochemistry Int. 2, 397–406 (1965)
Knight, C.A.: The freezing of supercooled liquids. New York: Van Nostrand 1967
Leveson, D. J.: Origin of comb layering and orbicular structure, Sierra Nevada Batholith, California: Discussion. Geol. Soc. Am. Bull. 84, 4005–4006 (1973)
Lofgren, G.: Experimental crystallization of synthetic plagioclase at prescribed cooling rates. E.O.S. 54, 482 (1973)
Lofgren, G.: An experimental study of plagioclase crystal morphology: Isothermal crystallization. Am. J. Sci. 274, 243–273 (1974)
Lofgren, G., Donaldson, C.H.: Experimental evidence bearing on the origin of “Comb (Willow Lake) Layering.” Geol. Soc. Am. Abst. with Programs 5, 716 (1973)
Loomis, A.A.: Noritic anorthositic bodies in the Sierra Nevada batholith. Mineral. Soc. Am. Spec. Paper 1, 62–68 (1963)
Moore, J.G., Lockwood, J.P.: Origin of comb layering and orbicular structure, Sierra Nevada batholith, California. Bull. Geol. Soc. Am. 84, 1–20 (1973a)
Moore, J.G., Lockwood, J.P.: Origin of comb layering and orbicular structure, Sierra Nevada Batholith, California: Reply. Geol. Soc. Am. Bull. 84, 4007–4010 (1973b)
Nesbitt, R.W.: Skeletal crystal forms in the ultramafic rocks of the Yilgarn Block, Western Australia: Evidence for an Archaean ultramafic liquid. Spec. Publs. Geol. Soc. Austr. 3, 331–347 (1971)
Platten, I.M., Watterson, J.S.: Oriented crystal growth in some tertiary dykes. Nature 223, 286–287 (1969)
Preston, J.: A columnar crystallization of olivine and plagioclase. Geol. Mag. 100, 1–6 (1963)
Pyke, D.R., Naldrett, A.J., Eckstrand, O.R.: Archaean ultramafic flows in Munro Township, Ontario. Geol. Soc. Am. Bull. 84, 955–978 (1973)
Tarshis, L.A., Tiller, W.A.: The effect of interface-attachment kinetics on the morphological stability of a planar interface during solidification. In: Crystal growth, H. S. Peiser, ed., p. 709–719. Oxford: Pergamon 1967
Taubeneck, W.H., Poldervaart, A.: Geology of the Elkhorn Mountains, Northeastern Oregon: Part 2. Willow Lake intrusion. Geol. Soc. Am. Bull. 71, 1295–1322 (1960)
Wager, L.R., Brown, G.M., Wadsworth, W. J.: Types of igneous cumulates. J. Petrol. 1, 73–85 (1960)
Wyllie, P. J., Drever, H.I.: The petrology of picritic rocks in minor intrusions — a picrite sill on the island of Soay (Hebrides). Trans. Roy. Soc. Edinburgh 65, 155–177 (1963)
Van Diver, B.B., Maggetti, M.: Comb Layering and orbicular structure in the Reichenbach orbiculite, Odenwald, West Germany. Geol. Soc. Am. Abst. with Programs 7, 846–847 (1973)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lofgren, G.E., Donaldson, C.H. Curved branching crystals and differentiation in comb-layered rocks. Contr. Mineral. and Petrol. 49, 309–319 (1975). https://doi.org/10.1007/BF00376183
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00376183