Publication Date:
2017-04-04
Description:
The crystal fabric of a lava has been analyzed for the first time by neutron texture diffraction. In this
study we quantitatively investigate the crystallographic preferred orientation of feldspars in the Castello
d’Ischia (Ischia Island, Italy) trachytic exogenous dome. The crystallographic preferred orientation was
measured with the monochromatic neutron texture diffractometer SV7 at the Forschungszentrum Jülich in
Germany and a Rietveld refinement was applied to the sum diffraction pattern. The complementary thin
section analysis showed that the three-dimensional crystal shape and the corresponding shape preferred
orientation are in agreement with the quantitative orientation distributions of the neutron texture data. The
(0k0) crystallographic planes of the feldspars are roughly parallel to the local flow bands, whereas the other
corresponding pole figures show that a pivotal rotation of the anorthoclase and sanidine crystals was active
during the emplacement of this lava dome. In combination with scanning electron microscopy investigations, electron probe microanalysis, XRF, and X-ray diffraction, the Rietveld refinement of the neutron diffraction
data indicates a slow cooling dynamic on the order of several months during their crystallization under
subaerial conditions. Results attained here demonstrate that neutron texture diffraction is a powerful tool that
can be applied to lava flows.
Description:
Published
Description:
179-196
Description:
3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
Description:
3.6. Fisica del vulcanismo
Description:
JCR Journal
Description:
restricted
Keywords:
neutron diffraction
;
crystal fabric
;
04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks
;
04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology
;
04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry
;
04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
;
04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
;
05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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