| 4192 |
Creator |
169f034520be3a0d0aff86e4441f6f0e |
| 4192 |
Creator |
a83b960ddf2843a8567430721dcd0f08 |
| 4192 |
Creator |
72eb7170d8a19be385f16460fd117c8e |
| 4192 |
Creator |
ext-2a092d1d3576a76c00b6d80098276a2a |
| 4192 |
Creator |
ext-4ed54935726ad03db9f7c83f1289e6ac |
| 4192 |
Creator |
ext-e0e21682cd919d7aeace93690cabc3da |
| 4192 |
Date |
2005-01 |
| 4192 |
Is Part Of |
repository |
| 4192 |
Is Part Of |
p14602415 |
| 4192 |
abstract |
Young (<65 ka) explosive silicic volcanism at Taupo volcano, New Zealand, has involved
the development and evacuation of several crustal magmatic systems. Up to and including
the 26·5 ka 530 km3 Oruanui eruption, magmatic systems were contemporaneous but geographically
separated. Subsequently they have been separated in time and have vented from geographically
overlapping areas. Single-crystal (secondary ionization mass spectrometry) and multiple-crystal
(thermal ionization mass spectrometry) zircon model-age data are presented from nine
representative eruption deposits from 45 to 3·5 ka. Zircon yields vary by three orders
of magnitude, correlating with the degrees of zircon saturation in the magmas, and
influencing the spectra of model ages. Two adjacent magma systems active up to 26·5
ka show wholly contrasting model-age spectra. The smaller system shows a simple unimodal
distribution. The larger system, using data from three eruptions, shows bimodal model-age
spectra. An older 100 ka peak is interpreted to represent zircons (antecrysts) derived
from older silicic mush or plutonic rocks, and a younger peak to represent zircons
(phenocrysts) that grew in the magma body immediately prior to eruption. Post-26·5
ka magma batches show contrasting age spectra, consistent with a mixture of antecrysts,
phenocrysts and, in two examples, xenocrysts from Quaternary plutonic and Mesozoic–Palaeozoic
metasedimentary rocks. The model-age spectra, coupled with zircon-dissolution modelling,
highlight contrasts between short-term silicic magma generation at Taupo, by bulk
remobilization of crystal mush and assimilation of metasediment and/or silicic plutonic
basement rocks, and the longer-term processes of fractionation from crustally contaminated
mafic melts. Contrasts between adjacent or successive magma systems are attributed
to differences in positions of the source and root zones within contrasting domains
in the quartzo-feldspathic (<15 km deep) crust below the volcano. |
| 4192 |
authorList |
authors |
| 4192 |
issue |
1 |
| 4192 |
status |
peerReviewed |
| 4192 |
volume |
46 |
| 4192 |
type |
AcademicArticle |
| 4192 |
type |
Article |
| 4192 |
label |
Charlier, B.L.A. ; Wilson, C.J.N.; Lowenstern, J.B.; Blake, S. ; van Calsteren, P.W.
and Davidson, J.P. (2005). Magma Generation at a Large, Hyperactive Silicic Volcano
(Taupo, New Zealand) Revealed by U–Th and U–Pb Systematics in Zircons. Journal of
Petrology, 46(1) pp. 3–32. |
| 4192 |
label |
Charlier, B.L.A. ; Wilson, C.J.N.; Lowenstern, J.B.; Blake, S. ; van Calsteren,
P.W. and Davidson, J.P. (2005). Magma Generation at a Large, Hyperactive Silicic
Volcano (Taupo, New Zealand) Revealed by U–Th and U–Pb Systematics in Zircons. Journal
of Petrology, 46(1) pp. 3–32. |
| 4192 |
Title |
Magma Generation at a Large, Hyperactive Silicic Volcano (Taupo, New Zealand) Revealed
by U–Th and U–Pb Systematics in Zircons |
| 4192 |
in dataset |
oro |