Gold rich chimneys from the Mariana back-arc basin
Chimney and mound samples collected from two hydrothermal vent fields in the MarianaBack-arc Basin by the submersible Shinkai 6500were studied geochemically. One of hydrothermal vent fields is so called Forecast Vent Field at the depth of 1450 m in the South Mariana Trough, and another deeper field is so called Alice Spring Field at the depth of 3600 m in the Middle ( or Central )Mariana Trough. Ore and gangue minerals from the both hydrothermal fields are similar, but the quantity of them is different in each field. Sphalerite contains FeS up to 2.5 mol％. Bulk chemical analyses of chimney and mound samples from the Mariana Back-arc Basin reveal the high precious and base metal contents. Chimneys from the South Mariana Trough contain 9 to 80 ppm Au with an average of 23 ppm Au (n=13). These also have high silver contents of an average of 355 ppm Ag (n=13).Pyrite contains Au and As. The existing form of Au was considered. Fluid inclusion and sulfur isotope of sulfides and sulfates were also examined.
Mariana chimney ore mineral gold
H.Ueno C.Iwaida I.Yamashita A.Kitakaze
Department of Environmental Security System, Faculty of Risk and Crisis Management Chiba Institute o Department of Earth and Environmental Sciences, Faculty of Science, Kagoshima University Kagoshima C Center for Northeast Asian Studies, Tohoku University, Sendai City 980-8576, Japan
国际会议
第八届国际矿床地质会议(Proceedings of the Eighth Biennial SGA Meeting)
北京
英文
23-26
2005-08-18（万方平台首次上网日期，不代表论文的发表时间）