Hydrothermal activity in the Lau back-arc basin: Sulfides and water chemistry

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1991)019<0303:HAITLB>2.3.CO;2· OSTI ID:5627351

Fouquet, Y; Charlou, J L; Donval, J P; Foucher, J P ^[1]; von Stackelberg, U; Wiedicke, M ^[2]; Erzinger, J ^[3]; Herzig, P ^[4]; Muhe, R ^[5]; Soakai, S ^[6]; Whitechurch, H ^[7]

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1. Institut Francais de Recherche et d'Exploitation de la Mer, Plouzane (France)
2. Bundesanstalt fur Geowissenschaften und Rohstoffe, Hannover (Germany)
3. Justus-Liebig-Universitat, Giessen (Germany)
4. Rheinish-Westfalische Technische Hochschule, Aachen (Germany)
5. Universitat Kiel (Germany)
6. Ministry of Lands Survey and Natural Resources, Nuku'Alofa (Tonga)
7. Ecole et Observatoire de Physique du Globe de Strasbourg (France)

The submersible Nautile completed 22 dives during the Nautilau cruise (R/V Nadir, April 17-May 10, 1989) for a detailed investigation of the southern Lau basin near Tonga. The objective of the scientific team from France, Germany, and Tonga was to understand the process of sea-floor ore formation associated with hydrothermal circulation along the Valu Fa back-arc ridge behind the Tonga-Kermadec trench. The four diving areas, between lat21{degree}25'S and 22{degree}40'S in water{approximately}2000 m deep, were selected on the basis of results from cruises of the R/V Jean Charcot and R/V Sonne. The Nadir cruise provided proof of hydrothermal activity-in all for areas, over more than 100 km-as indicated by the widespread occurence of hydrothermal deposits and by heat flow, conductivity, and temperature measurements near the sea bottom. The most spectacular findings were high-temperature white and black smokers and associated fauna and ore deposits. Hydrothermal water chemistry and sulfide composition data presented here indicate that this hydrothermal field is very different from the hydrothermal fields in oceanic ridges. This difference is seen in water chemistry of the hydrothermal fluid (pH=2 and high metal content) and the chemical composition of sulfides (enrichment in Ba, As, and Pb).

• OSTI ID: 5627351
• Journal Information: Geology; (USA), Vol. 19:4; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
HYDROTHERMAL SYSTEMS
GEOCHEMISTRY
WATER CHEMISTRY
PACIFIC OCEAN
ARSENIC
BARIUM
CHEMICAL COMPOSITION
COMPARATIVE EVALUATIONS
ENRICHMENT
EXPLORATION
GEOLOGIC FORMATIONS
GEOLOGY
HEAT FLOW
LEAD
METALS
ORES
PH VALUE
RESERVOIR FLUIDS
SULFIDES
SYNTHESIS
TEMPERATURE MEASUREMENT
THERMAL CONDUCTIVITY
TRUST TERRITORY OF THE PACIFIC ISLANDS
VOLCANIC ROCKS
ALKALINE EARTH METALS
CHALCOGENIDES
CHEMISTRY
DEVELOPED COUNTRIES
ELEMENTS
ENERGY SYSTEMS
FLUIDS
GEOTHERMAL SYSTEMS
IGNEOUS ROCKS
ISLANDS
NORTH AMERICA
PHYSICAL PROPERTIES
ROCKS
SEAS
SEMIMETALS
SULFUR COMPOUNDS
SURFACE WATERS
THERMODYNAMIC PROPERTIES
USA
150200* - Geology &amp; Hydrology of Geothermal Systems
150302 - Geothermal Exploration &amp; Exploration Technology- Geochemical Techniques &amp; Surveys