Chemically rich and diverse submarine hydrothermal plumes of the southern Kermadec volcanic arc (New Zealand)статья из журнала
Аннотация: Abstract The New Zealand American PLUme Mapping Expedition (NZAPLUME) provided the first systematic survey of chemical emissions along a submarine volcanic frontal arc. Chemical plumes emanated from seven of 13 volcanoes that line a 260 km-long section of the southern Kermadec arc northeast of New Zealand. Hydrothermal plumes ranged in depth from <200 to 1500 m and are generally more shallow than plumes over mid-ocean ridges (MORs). The chemical signatures of plumes along the southern Kermadec arc are unusually diverse and have concentration anomalies for CO 2 , H 2 S and Fe that can exceed those for MOR settings by 5–10 times, or more. Projected end-member fluid concentrations of carbon and sulphur gases at some volcanoes require a magmatic vapour source, while unusually high Fe concentrations and Fe/Mn values are consistent with venting an iron-rich magmatic brine. Thus, vent-fluid emissions on the Kermadec arc volcanoes often appear as hybrid mixtures of hydrothermally evolved sea water influenced by water-rock reaction with compositionally diverse arc lavas, and exsolved magmatic fluid present as gaseous (CO 2 and SO 2 +H 2 S) and liquid (Fe-rich brines) components. While rock-buffered fluids in arc settings are expected to vary compositionally from one another and from MOR fluids, it is the magmatic components that clearly differentiate arc emissions as being super-enriched in sulphur gases and ionic metals. These first systematic observations of spatially frequent and chemically robust fluid emissions from southern Kermadec arc forecast arcs as being a potentially important source of chemicals to the oceans.
Год издания: 2003
Авторы: Gary J. Massoth, Cornel E.J. de Ronde, J. E. Lupton, Richard A. Feely, Edward T. Baker, Geoffrey T. Lebon, Stacy M Maenner
Издательство: Geological Society of London
Источник: Geological Society London Special Publications
Ключевые слова: Hydrocarbon exploration and reservoir analysis, Paleontology and Stratigraphy of Fossils, Geochemistry and Geologic Mapping
Открытый доступ: closed
Том: 219
Выпуск: 1
Страницы: 119–139