Calcium Amphibole from Igneous rocks: Mineralogical Pressure Indicators
Abstract
The two methods of PH2O determination based on A16 vs. Si (Raase, 1974) and NaM4 vs. Al4 (Brown, 1977) used for amphiboles from metamorphic rocks have been applied to igneous amphiboles (pargasites and their actinolitic overgrowths) from the appinite suite of Scotland, U.K. The method of Raase (1974) is useful for both pargasitic and actinolitic compositions from the appinite suite. The method of Brown (1977) can be applied only to pargasitic compositions. In the actinolitic overgrowths the partitioning of the NaM4 content does not indicate a relation to the existing PH2O because of crystal chemical limitations.
References
Anderson. J.G.C., 1935. The Arrochar intrusive complex. Geol. Mag. 72, 263-83.
Anderson. J.G.C., 1937. Intrusions of Glen Follach area. Geol. Mag. 74, 458-48.
Bailey, E.B. & Maufe, H.B., 1916 (1960, 2nd ed.). The geology of Ben Nevis and Glen Coe and the surrounding country (Expl. Sheet 53). Mem. Geol. Sum. Scotland.
Bowes, D.R., 1962. Kentallenite-lamprophyre-granite age relations in Kentallen, Argyll. Geol. Mag. 99, 119-22.
Bowes, D.R., Kinloch, E.D. & Wright, A.E., 1964. Rhythmic amphibole overgrowths in appinites associated with explosion-breccias in Argyll. Mineral. Mag. 33, 963-73.
Bowes, D.R., MacDonall, A.S. Matheson, G.D. and Wright, A.E., 1963. An explosion-breccia-appinite complex at Gleann Charnan, Argyll. Trans. Geol. Soc. Glasgow 25, 19-30.
Bowes, D.R. & Wright, A.E., 1961. An explosion-breccia complex at Back Settlement, near Kentallen, Argyll. Trans. R. Soc. Edinburgh 18, 293-314.
Bowes, D.R. & Wright, A.E., 1967. The explosion-breccia pipes near Kentallen, Scotland, and their geological setting. Trans. R. Soc. Edinb. 67, 109-42.
Brown, E. H., 1977. The crossite content of Ca-amphibole as a guide to pressure of metamorphism. J. Petrol. 18, 53-72.
Hamidullah, S., 1983. Petrogenetic studies of the appinite suite of western Scotland. Thesis, Ph.D. (unpubl.) University of Glasgow, U.K.
Hietanen, A., 1974. Amphibole pairs, epidote minerals, chlorite and plagioclase in metamorphic rocks, northern Sierra Nevada, California. Am. Min. 59, 22-40.
Hollister, I., S., Grissom, G. C., Peters, E. K., Stowell, H. H. & Sisson, V. B., In prep, A test and refinement of the emperical correlation of aluminium in hornblende with pressure of crystallization of calc-alkaline plutons.
Leake, BB., 1971. On aluminous and edinitic hornblendes. Min. Mag. 38, 389-407.
McArthur, A.C., 1971. On the structural control of Caledonian igneous masses in the south-west Highlands of Scotland. Thesis, Ph.D. (unpubl.) University of Glasgow.
Miyashiro, A., 1973. Metamorphism and metamorphic belts. George Allen & Unwin, London.
Nockolds, S.R., 1941. The Garabal Hill-Gbn Fyne igneous complex. Q.J. Geol. Soc. Lond. 96, 451-511.
Platten, LM, 1966. The petrology of some Caledonian minor intrusions, Appin. Argyllshire. Thesis. Ph.D. (unpubl.) University of London.
Raase, P., 1974. A1 and Ti content of hornblende. Indicators of pressure and temperature of metamorphism. Contr. Min. Pet. 45, 231-6.
Read, H.H., 1961. Aspects of Cledonian magmatism in Britain, Liverpool Manchester Geol. J. 2, 653-83.
Robinson, P., Spear, F.S., Schumacher, J.C., Laird, J., Klein, C., Evans, B.W. & Doolan, B.L. 1982. Phase relations of metamorphic amphiboles: natural occurrence and theory. In: (Veblen D.R. & Ribbe, P.H. eds.). Reviews in Mineralogy. Amphiboles: Petrology and experimental phase relations. Spec. Pub. Min. Soc. Am. 9B, 1-228.
