Library Open Repository

The role of fluorine in the concentration and transport of lithophile trace elements in felsic magmas: Insights from the Gawler Range Volcanics, South Australia

Downloads

Downloads per month over past year

Agangi, A and Kamenetsky, VS and McPhie, J (2010) The role of fluorine in the concentration and transport of lithophile trace elements in felsic magmas: Insights from the Gawler Range Volcanics, South Australia. Chemical Geology, 273 (3-4). pp. 314-325. ISSN 0009-2541

[img]
Preview
PDF
CG_2010_GRV.pdf | Download (3MB)
Available under University of Tasmania Standard License.

Abstract

Rhyolites of the Mesoproterozoic Gawler Range Volcanics (GRV) of South Australia are characterised by high concentrations of some trace elements (REE, Y. HFSE, Rb and F, in particular). Whole rock geochemical data suggest that these elements were incompatible during magma crystallisation. Accessory minerals (fluorite, zircon, REE-F-carbonate, Ti oxide, apatite, and titanite) can account for most of the trace element content of the rocks. These minerals occur in vesicles, micromiaroles, lithophysal vugs and in interstices between major mineral phases (quartz and feldspar as both phenocrysts and groundmass). Such textural evidence indicates that accessory minerals crystallised late in the history of the magma and that they were deposited from a volatile-rich (fluid) phase. These features are explained by the following sequence of events: 1) F dissolved in the magma lowered the crystallisation temperature of accessory minerals, causing trace elements (REE, Y. and HFSE) to behave as incompatible elements. 2) Protracted crystallisation of major mineral phases (quartz, feldspar, and oxides) formed a volatile- and trace element-enriched residual liquid. 3) A volatile element (H2O, F, and CO2)-rich phase (late-stage magmatic fluid) evolved from the magma. High concentration of fluorine and other complexing agents in this phase allowed trace elements to be transported in solution. 4) Accessory minerals crystallised from such a phase in vesicles, micromiaroles and interstices between the major mineral phases

Item Type: Article
Keywords: Fluorine Rare earth elements (REE) High field strength elements (HFSE) Late-stage magmatic fluid
Journal or Publication Title: Chemical Geology
Page Range: pp. 314-325
ISSN: 0009-2541
Identification Number - DOI: 10.1016/j.chemgeo.2010.03.008
Additional Information: The definitive version is available at http://www.sciencedirect.com
Date Deposited: 12 Oct 2010 04:26
Last Modified: 18 Nov 2014 04:13
URI: http://eprints.utas.edu.au/id/eprint/10216
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page