Tateya
Tateya, Akiruno city, Tokyo, Japan
Occurrence
Glendonite, mineral-like material, formed on the sea floor during deposition of mudstone-sandstone alternating beds of the early Miocene (19 Ma) Kosho Formation. The Kosho Formation is composed of abyssal sediments. The Kosho Formation conformably overlies the conglomerate-dominant Uchimura Formation, and conformably underlies the mudstone-dominant Aoki Formation. Ages of sedimentary rocks were determined by microfossils and fossil bivalvia.
Glendonite in mudstone of the Kosho Formation. A light gray twinned glendonite is at the right of the scale coin. Two long bipyramidal crystals of glendonite form a X-shaped twin-like structure. The flat surface of this outcrop is a bedding plane of mudstone along the boundary between mudstone and sandstone in alternating beds of them. Glendonite is parallel to sub-parallel to the bedding plane.
Reported Minerals
- Glendonite
- Pyrite
Mineral Assemblages
- Glendonite
Localities
- Tateya (Glendonite)
- Kodo (Glendonite)
- Iseyama (Glendonite)
- Teradomari (Glendonite)
- (Methane hydrate)