Mount Ryogai
Ashikaga city, Tochigi pref., Japan
Occurrence
Bedded manganese deposit (Diagenesis)
Manganese nodules preserving original chemical composition and sedimentary structures. These manganese nodules are on the surface of Unit 3 of Kuzu Complex, a member of Jurassic accretionary complex Ashio Belt.
Outcrop of manganese nodules associated with bedded chert block in Unit 3 of Kuzu Complex. Black nodules are manganese nodules. The pale brown host is chert. Shape and occurrence are similar to those of manganese nodules on the ocean floor. Chemical composition is same as that of cobalt-rich manganese crust on the present ocean floor.
Reported Minerals
- Manganese dioxide
Mineral Assemblage
- Chert(Host) - Manganese dioxide
Localities
- Mount Ryogai (Mn nodule)
- Mount Hachioji (Mn nodule)
- Yahazu Mine (Mn dioxide)
- Goshonoiri Mine (Mn dioxide)
Related Occurrences
- Bedded Mn (Diagenesis)
- Bedded Mn (Low-T zeolite facies)
- Bedded Mn (High-T zeolite facies)
- Bedded Mn (Prehnite-Pumpellyite facies)
- Bedded Mn (Pumpellyite-Actinolite facies)
- Bedded Mn (Greenschist facies)
- Bedded Mn (Epidote-Amphibolite facies)
- Bedded Mn (Amphibolite facies)
- Bedded Mn (Albite-Epidote-hornfels facies)
- Bedded Mn (Hornblende-hornfels facies)
- Bedded Mn (Pyroxene-hornfels facies)