Wad
Chemical Process (Liquid-phase growth) - Ground surface
Required Geological Setting
Occurrence
Manganese dioxide deposits precipitated from the hot spring water. It is considered that Mn ions in the hot springs was deposited as buserite by the activity of manganese-oxidizing bacteria in the hot spring water. These deposits have been studied as modern analogies of huge manganese oxide deposits formed during the Precambrian period (575 Ma) or older.
Reported Minerals
- Buserite
- Birnessite
- Todorokite
Localities
- Yu-no-Taki Fall, Lake Onneto (Modern)
Related Occurrences
- Travertine (Calcareous sinter)
- Siliceous sinter
- Sulphur sinter
- Vitriolic sinter