Koura-ga-hana
Kitaura, Mihonoseki village, Matsue city, Shimane pref., Japan
Occurrence
Prehnite-Pumpellyite facies metamorphic rocks
Prehnite-Pumpellyite-Fe2+ veins in dolerite. This dolerite is the middle Miocene (13 Ma) laccolith intruded in the middle Miocene (13 Ma) Ushikiri Formation, and is related to the rhyolitic to dacitic activity of the submarine volcano. The age of dolerite was determined by K-Ar radiometric dating of whole rock.
Prehnite vein in dolerite. Grayish-green veins at both sides of the coin are composed of prehnite, and grayish-green color is by pumpellyite-Fe2+. As shown in this photograph, the width of the vein changes in the short distance. Black babingtonite crystals are perched on botryoidal aggregates of prehnite. The center of the vein is filled with white calcite as shown at the right vein. The surrounding host is dolerite with white anorthite grains.
Reported Minerals
- Prehnite
- Babingtonite
- Pumpellyite-Fe2+
- Calcite
- Laumontite
Mineral Assemblages
- Prehnite - Babingtonite - Calcite
- Pumpellyite-Fe2+
- Laumontite
Localities
- Onna-Saka (Basalt)
- Hirayama (Basalt)
- Kouragahana (Pillow lava)
- Nakayashiki (Hyaloclastite)
- Iwakake (Hyaloclastite)
- Yadoriki (Tuff)
- Heguri (Sandstone, Gabbro)
- Mount Chiba (Datolite)
- Kami-Ochiai (Axinite-Datolite)
- Nyushima (Axinite-Datolite)
Related Occurrences
- Albite-Epidote-hornfels facies
- Hornblende-hornfels facies
- Pyroxene-hornfels facies
- Sanidinite-hornfels facies