Contrasting evolution of hydrothermal fluids in the PACMANUS system, Manus Basin: The Sr and S isotope evidence
- S. Roberts1,
- W. Bach2,
- R.A. Binns3,
- D.A. Vanko4,
- C.J. Yeats5,
- D.A.H. Teagle6,
- K. Blacklock7,
- J.S. Blusztajn8,
- A.J. Boyce9,
- M.J. Cooper10,
- N. Holland10 and
- B. McDonald11
- 1School of Ocean and Earth Science, Southampton Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
- 2Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
- 3Commonwealth Scientific and Industrial Research Organisation Exploration and Mining, P.O. Box 136, North Ryde, NSW 1670, Australia
- 4Department of Physics, Astronomy and Geosciences, Towson University, Towson, Maryland 21252, USA
- 5Commonwealth Scientific and Industrial Research Organisation Exploration and Mining, P.O. Box 136, North Ryde, NSW 1670, Australia
- 6School of Ocean and Earth Science, Southampton Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
- 7Commonwealth Scientific and Industrial Research Organisation Petroleum Resources, P.O. Box 136, North Ryde, NSW 1670, Australia
- 8Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
- 9Scottish Universities Environmental Research Centre, Rankine Avenue, East Kilbride G70 0QF, UK
- 10School of Ocean and Earth Science, Southampton Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
- 11Commonwealth Scientific and Industrial Research Organisation Exploration and Mining, P.O. Box 136, North Ryde, NSW 1670, Australia
Abstract
Ocean Drilling Program (ODP) Leg 193 investigated two sites of hydrothermal activity along the crest of the Pual Ridge in the eastern Manus Basin. A site of low-temperature diffuse venting, Snowcap (Site 1188), and a high-temperature black smoker site, Roman Ruins (Site 1189), were drilled to depths of 386 and 206 m below seafloor (mbsf), respectively. Although the two sites are <1000 m apart, the 87Sr/86Sr and δ34S signatures of anhydrite recovered at both sites are very different. The data suggest a complex interplay among hydrothermal fluid, magmatic fluid, and seawater during alteration and mineralization of the PACMANUS (Papua New Guinea–Australia–Canada–Manus) system. These new results significantly expand the subsurface data on seafloor hydrothermal systems and may begin to explain the earliest processes of multistage mineralization and alteration history that typify ancient massive sulfide systems.
Footnotes
-
- Accepted May 11, 2003.
- Received April 2, 2003.
- Revision received May 5, 2003.
- Geological Society of America
