Low-pressure, water-assisted anatexis of basic dykes in a contact metamorphic aureole, Fuerteventura (Canary Islands): oxygen isotope evidence for a meteoric fluid origin

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Version: Final published version
Serval ID
serval:BIB_24A646C19CEA
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Low-pressure, water-assisted anatexis of basic dykes in a contact metamorphic aureole, Fuerteventura (Canary Islands): oxygen isotope evidence for a meteoric fluid origin
Journal
Contributions to Mineralogy and Petrology
Author(s)
Holloway M.I., Bussy F., Vennemann T.W.
ISSN-L
0010-7999
Publication state
Published
Issued date
2008
Peer-reviewed
Oui
Volume
155
Pages
111-121
Language
english
Abstract
Migmatites produced by low-pressure anatexis of basic dykes are found in
a contact metamorphic aureole around a pyroxenite-gabbro intrusion
(PX2), on Fuerteventura. Dykes outside and inside the aureole record
interaction with meteoric water, with low or negative delta O-18
whole-rock values (+0.2 to -3.4 parts per thousand), decreasing towards
the contact. Recrystallised plagioclase, diopside, biotite and oxides,
from within the aureole, show a similar evolution with lowest delta O-18
values (-2.8, -4.2, - 4.4 and -7.6 parts per thousand, respectively) in
the migmatite zone, close to the intrusion. Relict clinopyroxene
phenocrysts preserved in all dykes, retain typically magmatic delta O-18
values up to the anatectic zone, where the values are lower and more
heterogeneous. Low delta O-18 values, decreasing towards the intrusion,
can be ascribed to the advection of meteoric water during magma
emplacement, with increasing fluid/rock ratios (higher dyke intensities
towards the intrusion acting as fluid-pathways) and higher temperatures
promoting increasing exchange during recrystallisation.
Create date
29/09/2012 16:23
Last modification date
20/08/2019 13:02
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