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Mineral fractionation and pre- and post-emplacement processes in the uppermost part of the Shiant Isles Main Sill

Published online by Cambridge University Press:  05 July 2018

C. M. B. Henderson ,
F. G. F. Gibb  and
K. A. Foland
C. M. B. Henderson*
Affiliation:
Department of Earth Sciences, University of Manchester, Manchester M13 9PL, UK
F. G. F. Gibb
Affiliation:
Environmental & Geological Sciences, University of Sheffield, Sheffield S3 7HF, UK
K. A. Foland
Affiliation:
Department of Geological Sciences, Ohio State University, Columbus, Ohio 43210, USA
*
*E-mail: [email protected]
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Abstract

Reinvestigation of the top 25 m of the 165 m thick Shiant Isles Main Sill requires reinterpretation of its internal structure, especially of the last unit emplaced – the granular olivine picro-dolerite. New mineral analyses allow re-assessment of the magmatic processes involved in the intrusion and differentiation of this classic multiple sill. C-shaped vertical mineral composition profiles, which occur in olivine-rich, alkaline basaltic sills, reflect reaction between phenocrysts and variable composition liquids. A case is made for vertical migration of interstitial liquids within and across the boundaries of intrusive units, for the mixing of such liquids from adjacent units, and for their influence on mineral chemistry on both sides of the interface.

Keywords

picro-doleriteolivinemineral fractionationinterstitial liquidShiant Isles
Type
Research Article
Information
Mineralogical Magazine , Volume 64 , Issue 5 , October 2000 , pp. 779 - 790
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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References

Drever, H.I. and Johnston, R. (1965) New petrographical data on the Shiant Isles picrite. Mineral. Mag., 34, 194–203.Google Scholar
Foland, K.A., Gibb, F.G.F. and Henderson, C.M.B. (2000) Patterns of Sr and Nd isotopic compositions produced by magmatic and post-magmatic contamination in the Shiant Isles Main Sill, Scotland. Contrib. Mineral. Petrol, (in press).CrossRefGoogle Scholar
Gibb, F.G.F. (1968) Flow differentiation in the xenolithic sills and dykes of the Cuillins and the Strathaird Peninsula, Isle of Skye. J. Petrol., 9, 411–43CrossRefGoogle Scholar
Gibb, F.G.F. (1973) The zoned clinopyroxenes of the Shiant Isles Sill, Scotland. J. Petrol, 14, 203–30.CrossRefGoogle Scholar
Gibb, F.G.F. and Henderson, C.M.B. (1978) The petrology of the Dippin sill, Isle of Arran. Scot. J. Geol, 14, 1–27.CrossRefGoogle Scholar
Gibb, F.G.F. and Henderson, C.M.B. (1989) Discontinuities between picritic and crinanitic units in the Shiant Isles sill: evidence of multiple intrusion. Geol Mag., 126, 127–37.CrossRefGoogle Scholar
Gibb, F.G.F. and Henderson, C.M.B. (1992) Convection and crystal settling in sills. Contrib. Mineral. Petrol, 109, 538–45.CrossRefGoogle Scholar
Gibb, F.G.F. and Henderson, C.M.B. (1996) The Shiant Isles Main Sill: structure and mineral fractionation ranges. Mineral. Mag., 60, 67–97.CrossRefGoogle Scholar
Helz, R.T., Kirschenbaum, H. and Marinenko, J.W. (1989) Diapiric transfer of melt in Kilauea Iki lava lake, Hawaii: a quick, efficient process of igneous differentiation. Geol. Soc. Amer. Bull, 101, 578–94.2.3.CO;2>CrossRefGoogle Scholar
Henderson, P. and Suddaby, P. (1971) The nature and origin of the chrome-spinel of the Rhum layered intrusion. Contrib. Mineral. Petrol., 33, 21–31.CrossRefGoogle Scholar
Johnston, R. (1953) The olivines of the Garbh Eilean sill, Shiant Isles. Geol. Mag., 90, 161–71.CrossRefGoogle Scholar
Komar, P.D. (1972) Mechanical interactions of pheno-crysts and flow differentiation of igneous dykes and sills. Geol. Soc. Amer. Bull., 83, 973–88.CrossRefGoogle Scholar
Marsh, B.D. (1996) Solidification fronts and magmatic evolution. Mineral. Mag., 60, 5–40.CrossRefGoogle Scholar
Powell, R. and Powell, M. (1977) Geothermometry and oxygen barometry using coexisting iron-titanium oxides: a reappraisal. Mineral. Mag., 41, 257–63.CrossRefGoogle Scholar
Sack, R.O. and Ghiorso, M.S. (1991) Chromite as a petrogenetic indicator. Pp. 323–53 in: Oxide Minerals (Lindsley, C.D.H., editor). Reviews in Mineralogy, 25. Mineralogical Society of America, Washington D.C. CrossRefGoogle Scholar
Shirley, D.N. (1987) Differentiation and compaction in the Palisades Sill, New Jersey. J. Petrol., 28, 835–65.CrossRefGoogle Scholar
Wadsworth, W.J. (1988) Silicate mineralogy of the Middle Zone cumulates and associated gabbroic rocks from the Insch intrusion, NE Scotland. Mineral. Mag., 52, 309–22.CrossRefGoogle Scholar
Wager, L.R. and Brown, G.M. (1968) Layered Igneous Rocks (1st edn). Oliver & Boyd, Edinburgh.Google Scholar
Walker, F. (1930) The geology of the Shiant Isles (Hebrides). Q. J. Geol. Soc. Lond., 86, 355–98.CrossRefGoogle Scholar
Walker, K.R. (1973) Compositional variations in the pyroxenes of the differentiated Palisades Sill, New Jersey. Geol. Soc. Amer. Bull., 84, 89–110.2.0.CO;2>CrossRefGoogle Scholar