Problem in the diagnostics and petrogenesis of ignimbrites

Correct diagnostics of rocks requires the 3D study of the structure of their basis, since a splinter-like basis structure may occur only in a single observed section of a specimen of a rock that has a more complex structure of the plane-parallel or linear type. Ignimbrites differ from lavas with a s...

Full description

Saved in:
Bibliographic Details
Published in:Journal of volcanology and seismology 2009-04, Vol.3 (2), p.71-80
Main Author: Kurchavov, A. M.
Format: Article
Language:English
Subjects:
Earth and Environmental Science
Earth Sciences
Geochemistry
Geology
Geophysics/Geodesy
Mineralogy
Morphology
Petrology
Rocks
Silica
Volcanology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Correct diagnostics of rocks requires the 3D study of the structure of their basis, since a splinter-like basis structure may occur only in a single observed section of a specimen of a rock that has a more complex structure of the plane-parallel or linear type. Ignimbrites differ from lavas with a similar silica content primarily in the presence of fiamme, a smooth outline of the phenocrysts, and their constant cataclasis; they differ from pyroclastic lavas by having broken-down phenocrysts enclosed in an undisturbed groundmass with smooth and undulating outlines of the volcanic particles and by the presence of fiamme showing a regular pattern of evolving composition. The study of the morphological and material features of all components of ignimbrites in their relationships with the silica content of the melt and the attitude of the ignimbrite geologic bodies they compose corroborates the hypothesis that ignimbrites are generated by the complex evolution of a gas-saturated melt of the emulsified type rather than by baking (welding) of ash-fall particles.
ISSN:0742-0463
1819-7108
DOI:10.1134/S0742046309020018