Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-30T03:22:50.128Z Has data issue: false hasContentIssue false
  • English
  • Français

A new Tertiary sill complex of mid-ocean ridge basalt type NNE of the Shetland Isles: a preliminary report

Published online by Cambridge University Press:  03 November 2011

F. G. F. Gibb ,
R. Kanaris-Sotiriou  and
R. Neves
F. G. F. Gibb
Affiliation:
Department of Geology, University of Sheffield, Mappin Street, Sheffield S1 3JD, England.
R. Kanaris-Sotiriou
Affiliation:
Department of Geology, University of Sheffield, Mappin Street, Sheffield S1 3JD, England.
R. Neves
Affiliation:
Department of Geology, University of Sheffield, Mappin Street, Sheffield S1 3JD, England.
Get access Rights & Permissions [Opens in a new window]

Abstract

Basic intrusive rocks recently encountered in wells N and NNE of the Shetland Isles are probably parts of a single large sill complex which extends for over 130 km along the edge of the Faeroe-Shetland Trough. The sills intrude thick Mesozoic sediments which almost certainly overlie continental crust but the complex also appears to underlie, and extend beyond the SE edge of, the Faeroes basaltic lava plateau. Petrographic and geochemical analyses of drill core samples recovered from some of these sills reveal that they are of mid-ocean ridge basalt (MORB) type; an observation which provides evidence regarding the plate tectonic history of this area of the North Atlantic and has major implications for the nature of the continental/oceanic crust transition.

Keywords

continental marginMORBNorth Atlanticoceanic crustolivine tholeiite.
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 77 , Issue 3 , 1986 , pp. 223 - 230
Copyright
Copyright © Royal Society of Edinburgh 1986

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

Boillot, G. 1981. Geology of the continental margins, translated by Scarth, A.London: Longman.Google Scholar
Bollingberg, H., Brooks, K. C. & Noe-Nygaard, A. 1975. Trace element variation in Faeroese basalts and their possible relationships to ocean floor spreading history. BULL GEOL SOC DENMARK 24, 55–60.Google Scholar
Floyd, P. A. & Winchester, J. A. 1975. Magma type and tectonic setting discrimination using immobile elements. EARTH PLANET SCI LETT 27, 211–18.CrossRefGoogle Scholar
Gatliff, R. H., Hitchen, K., Ritchie, J. D. & Smythe, D. K. 1984. Internal structure of the Erlend Tertiary volcanic complex, north of Shetland, revealed by seismic reflection. J GEOL SOC LONDON 141, 555–62.CrossRefGoogle Scholar
Gibb, F. G. F. & Henderson, C. M. B. 1978. The petrology of the Dippin Sill, Isle of Arran. SCOTT J GEOL 14, 1–27.Google Scholar
Gibb, F. G. F. & Henderson, C. M. B. 1984. The structure of the Shiant Isles sill complex, Outer Hebrides. SCOTT J GEOL 20, 21–9.CrossRefGoogle Scholar
Larsen, L. M. & Watt, W. S. 1985. Episodic volcanism during break-up of the North Atlantic: evidence from the East Greenland plateau basalts. EARTH PLANET SCI LETT 73, 105–16.Google Scholar
Noe-Nygaard, A. & Rasmussen, J. 1968. Petrology of a 3000 m sequence of basaltic lavas in the Faeroe Islands. LITHOS 1, 286–304.Google Scholar
Pearce, T. H., Gorman, B. E. & Birkett, T. C., 1975. The TiO2-K2O-P2O5 diagram: a method of discriminating between oceanic and non-oceanic basalts. EARTH PLANET SCI LETT 24, 419–26.Google Scholar
Ridd, M. F. 1983. Aspects of the Tertiary geology of the Faeroe-Shetland Channel. In Bott, M. H. P., Sanov, F., Talwani, M. & Thiede, J. (eds) Structure and development of the Greenland-Scotland ridge, 91–108. London: Plenum.Google Scholar
Russell, M. J. 1976. A possible Lower Permian age for the onset of ocean floor spreading in the northern north Atlantic. SCOTT J GEOL 12, 315–24.Google Scholar
Schilling, J. G., Zajac, M., Evans, R., Johnston, T., White, W., Devine, J. D. & Kingsley, R. 1983. Petrologic and geochemical variations along the Mid-Atlantic Ridge from 29°N to 73°N. AM J SCI 283, 510–86.Google Scholar
Shervais, J. W. 1982. Ti-V plots and the petrogenesis of modern and ophiolitic lavas. EARTH PLANET SCI LETT 59, 101–118.Google Scholar
Smythe, D. K., Chalmers, J. A., Skuce, A. G., Dobinson, A. & Mould, A. S. 1983. Early opening history of the North Atlantic—I. Structure and origin of the Faeroe-Shetland Escarpment. GEOPHYS J R ASTR SOC 72, 373–398.Google Scholar
Treuil, M. & Varet, J. 1973. Criteres volcanologiques, petrologiques et geochimiques de la genese et de la differenciation des magmas basaltiques: example de l'Afar. BULL SOC GEOL FR 15, 506–540.CrossRefGoogle Scholar