Hydrothermal native copper in ocean island alkali basalt from the Mineoka belt, Boso Peninsula, Japan

• Published in: Economic Geology
• Main Authors: Ikehata, Kei, Choda, Koshuke, Tsunogae, Toshiaki, Bornhorst, Theodore J.
• Format: Text
• Language: unknown
• Published: Digital Commons @ Michigan Tech 2016
• Subjects: Geology; Ridge Island; Ocean Island
• Online Access: https://digitalcommons.mtu.edu/museum-p/3; https://doi.org/10.2113/econgeo.111.3.783

Native copper grains are found in aphyric amygdaloidal basalt of early Miocene age (ca. 20 Ma) in the southern Mineoka belt of Boso Peninsula, central Japan. The native copper was precipitated in the amygdules or veins along with calcite and analcime. The temperature of precipitation and salinity of...