Nagusa
Nagusa-Kamicho, Ashikaga city, Tochigi pref., Japan
Occurrence
Hornblende-hornfels facies contact metamorphic rocks
Mudstone of Kurohone-Kiryu Complex of Ashio Belt, a member of Jurassic accretionary complex, has been subjected to hornblende-hornfels facies contact metamorphism by Cretaceous granodiorite of Ashikaga Body, and andalusite was formed in it. Approximately 100 m apart from the heat source, Ashikaga Body.
Outcrop of andalusite-hornfels formed by hornblende-hornfels facies metamorphism of mudstone, a matrix of Kurohone-Kiryu Complex. The black outcrop is composed of andalusite-bearing hornfels, and flat schistosity was recognized. Andalusite is too small to see in this photograph but they are clear pale pink and aligned along schistosity.
Reported Minerals
- Andalusite
- Pyrite
Mineral Assemblages
- Hornfels - Andalusite - Pyrite
Localities
- Hiedano (Cordierite)
- Ginzan-Daira (Cordierite)
- Sori (Cordierite)
- Adachi (Cordierite)
- Nagusa (Andalusite)
- Yoshi-u (Dravite)
Related Occurrences
- Albite-Epidote-hornfels facies
- Hornblende-hornfels facies
- Pyroxene-hornfels facies
- Sanidinite-hornfels facies
- Pumpellyite-Actinolite facies
- Blueschist facies
- Epidote-Amphibolite facies
- Eclogite facies
- Ultrahigh-pressure faices