Umber and manganese ore in the Northern Shimanto Belt from Wakayama Prefecture
Umber (ferromanganese sediment) and manganese deposits occur in the Northern Shimanto Belt of Shikoku, Kii Peninsula, Boso Peninsula and east Hokkaido. REE compositions of the umber and manganese ores are similar to modern ferromanganese sediments near the Mid- Oceanic Ridges and modern manganese sediments at submarine hydrothermal system, respectively. The left photograph is polished umber sample from Itogo area (I-a12) and the right photograph is polished manganese ore sample from Ryujin area (R-a1). 5 cm in width.
(Takeru Moriyama)
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Geological Survey of Japan HP
National Institute of Advanced Industrial Science and Technology HP