Hornblende-hornfels facies

Chemical Process (Solid-phase growth) - Contact metamorphic facies series

Index Minerals

Hornblende

Required Geological Setting

Occurrence

Metamorphic rocks formed by contact metamorphism or regional metamorphism in the following condition: 450-650 degree and less than 0.2 GPa (shallower than 5 km depth). A metamorphic facies formed by heat of magma. Hornbelnde-hornfels facies metamorphic rocks are observed as contact metamorphic rocks aroud intrusions of plutonic rocks accidental fragments in pyroclastics, or xenoliths (xenocrysts) in igneous rocks.

Distribution of metamorphic rocks subjected to Hornblende-hornfels facies metamorphism described in this site. Protolith of blue dots is bedded Mn deposit, and protoliths of green dots are igneous rocks and sedimentary rocks. Yellow zones are sedimentary rocks, pink parts are S-type (Ilmenite series) plutonic rocks, and blue parts are I-type (Magnetite series) plutonic rocks.

Change of mineral assemblages

[ Extinct ] Epidote, Chlorite, Actinolite
[ Appear ] Hornblende, Cordierite

Mineral Assemblages

[ Felsic Rocks ] Microcline, Quartz, Muscovite, Plagioclase, Biotite, (Almandine)
[ Mafic Rocks ] Hornblende, Plagioclase, (Diopside, Anthophyllite)
[ Ultramafic Rocks ] Anthophyllite, Serpentine
[ Mudstone ] Muscovite/Andalusite, Biotite, Cordierite, Quartz, Plagioclase
[ Laterite ] Hercynite, Corundum, Titanite, Plagioclase, (Andalusite, Cordierite, Grossular)
[ Bedded Mn ] Hausmannite, Rhodonite, Spessartine, Rhodochrosite, Manganocummingtonite, Alabandite, Pyrrhotite
[ Carbonate Rocks ] Calcite/Dolomite, Tremolite, Quartz, Grossular, Plagioclase, Diopside, (Talc)

Localities

Hiedano (Cordierite)
Ginzan-Daira (Cordierite)
Sori (Cordierite)
Adachi (Cordierite)
Nagusa (Andalusite)
Yoshi-u (Dravite)

Related Occurrences

Other Occurrences