Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-11T13:41:18.405Z Has data issue: false hasContentIssue false
  • English
  • Français

Mineral-scale Sr isotope variation in plutonic rocks – a tool for unravelling the evolution of magma systems

Published online by Cambridge University Press:  12 August 2008

Jon P. Davidson ,
Laura Font ,
Bruce L. A. Charlier  and
Frank J. Tepley III
Jon P. Davidson
Affiliation:
Department of Earth Sciences, University of Durham, South Road, Durham DH1 3LE, UK. e-mail: j.p.davidson@durham.ac.uk
Laura Font
Affiliation:
Department of Earth Sciences, University of Durham, South Road, Durham DH1 3LE, UK. e-mail: j.p.davidson@durham.ac.uk
Bruce L. A. Charlier
Affiliation:
Department of Earth Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK.
Frank J. Tepley III
Affiliation:
College of Oceanic and Atmospheric Sciences, 104 COAS Admin Building, Oregon State University, Corvallis, OR 97331-5503, USA.
Get access Rights & Permissions [Opens in a new window]

Abstract

Isotope ratios of elements such as Sr, Nd, Pb and Hf can be used as tracers of magmatic sources and processes. Analytical capabilities have evolved so that isotope ratios can now be analysed in situ, and isotopic tracers can therefore be used within single minerals to track the changing magmatic environment in which a given mineral grew. This contribution shows that Sr isotope ratios in feldspars that make up plutonic rocks will typically preserve initial isotopic variations, provided precise and accurate age corrections can be applied. Variations in initial isotope ratio can give a core-to-rim record of magmatic evolution and can be used to diagnose open system events such as contamination and magma recharge and mixing.

New single grain Sr isotope data are presented from the Dais Intrusion, Antarctica, which reflect an open system origin for the crystals. The crystal cargo appears to be aggregated and assembled during transport and emplacement. This model, as opposed to a magma body crystallising post emplacement, may be more applicable to plutonic rocks in general, and is testable using the in situ isotopic determination methods described here.

Keywords

Cooling historiescrystal isotope stratigraphydifferentiationfeldsparsisotope ratios
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 97 , Issue 4 , 2008 , pp. 357 - 367
Copyright
Copyright © Royal Society of Edinburgh 2006

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.)