Eutaxitic Texture

Eutaxitic texture describes the layered or banded texture in explosive volcanic rocks. It is often caused by the compaction and flattening of glass shards and pumice fragments. Ignimbrites are typically characterized by fist-sized pumice fragments floating in a finer grained matrix but many ignimbrites, however, are still hot when they are emplaced so that the pumice and ash fragments are still plastic and malleable.

Thick, hot ignimbrites will often collapse under their own weight, thus fusing the fragments together to generate a welded flow. In such cases the pumice fragments are compacted into dark, glassy pancake shapes, called fiamme. A welded ignimbrite containing fiamme is said to have a eutaxitic texture

Bibliography



• Deer, W.A., Howie, R.A., Zussman, J. (1998) Rock-forming Minerals.
• Optical Mineralogy : The Nonopaque Minerals by Phillips / Griffen
• E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc
• Cox et al. (1979): The Interpretation of Igneous Rocks, George Allen and Unwin, London.

Photo
eutassiticapeperino(2).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(3).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(4).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(5).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(7).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(8).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(9).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(10).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(11).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(12).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassiticapeperino(13).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(2).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(5).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(3).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(4).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(8).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(6).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(7).jpg
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Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eeutassitica(9).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassitica2012a(2).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)
eutassitica2012a(37).jpg

Rheomorphic structures (flow structures) in a ignimbrite from vulsini (Italy). PPL image , 10x (Field of view = 2mm)