Submarine volcanoes and high-temperature hydrothermal venting on the Tonga arc, southwest Pacific
- Peter Stoffers1,
- Tim J. Worthington1,
- Ulrich Schwarz-Schampera2,
- Mark D. Hannington*3,
- Gary J. Massoth4,
- Roger Hekinian5,
- Mark Schmidt6,
- Lonny J. Lundsten7,
- Leigh J. Evans8,
- Rennie Vaiomo'unga9 and
- Terry Kerby10
- 1 Institute of Geosciences, University of Kiel, Olshausenstrasse 40, 24118 Kiel, Germany
- 2Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, 30655 Hannover, Germany
- 3Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa K1N 6N5, Canada
- 4Institute of Geological and Nuclear Sciences, PO Box 31312, Lower Hutt, New Zealand
- 5Keryunan, 29290 Saint Renan, France
- 6Institute of Geosciences, University of Kiel, Olshausenstrasse 40, 24118 Kiel, Germany
- 7Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, California 95039-9644, USA
- 8National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory, Hatfield Marine Center, 030 SE Marine Science Drive, Newport, Oregon 97365, USA
- 9Ministry of Lands, Survey and Natural Resources, Nuku'alofa, Kingdom of Tonga
- 10Hawaii Undersea Research Laboratory, University of Hawaii, 1000 Pope Road, Honolulu, Hawaii 96822, USA
Abstract
Submarine hydrothermal vents and associated seafloor mineralization on the Tonga arc have been found for the first time, in the summit calderas of two shallow-water volcanoes, greatly extending the known areas and diversity of seafloor hydrothermal activity in the western Pacific region. The highest temperature vents (245–265 °C) occur at water depths of 385–540 m near the summit of one volcano at 24°S. The vents are spatially related to basaltic dike swarms exposed at a summit cone and in the caldera walls. Clusters of large (to 10 m high) barite, anhydrite, and sulfide chimneys on the summit cone are vigorously discharging clear hydrothermal fluids with temperatures on the seawater boiling curve. There is abundant evidence of phase separation, which can be seen as flame-like jets of steam (H2O vapor) at the chimney orifices. Pyrite, marcasite, sphalerite, and chalcopyrite line the interiors of the highest temperature vents, similar to black smoker chimneys on the mid-ocean ridges.
Footnotes
-
↵*mhanning{at}uottawa.ca
-
↵GSA Data Repository item 2006114, shipboard methods, is available online at www.geosociety.org/pubs/ft2006.htm, or on request from editing{at}geosociety.org or Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301, USA.
-
- Accepted 20 January 2006.
- Received 19 October 2005.
- Revision received 5 January 2006.
- The Geological Society of America, Inc.
