HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schardt, C. Articles by Yang, J. Search for Related Content Articles by Schardt, C. Articles by Yang, J. GeoRef GeoRef Citation

Controls on Heat Flow, Fluid Migration, and Massive Sulfide Formation of an Off-axis Hydrothermal System— the Lau Basin Perspective

Christian Schardt^*,, Ross Large^* and Jianwen Yang^**

^* CODES ARC Centre of Excellence in Ore Deposits, University of Tasmania, Private Bag 79, Hobart, Tasmania, Australia 7001
^** Department of Earth Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada

Present address: Department of Earth and Planetary Sciences, The John Hopkins University, Baltimore, Maryland, 21218, USA; cschard1{at}jhu.edu

A numerical model has been developed to investigate heat and fluid migration in a modern off-axis seafloor hydrothermal system, that is, hydrothermal activity and fluid discharge distal to an axial magma chamber emphasizing model geometry, rock/fault properties and fault distribution. The model is based on geophysical data and seafloor observations of the Lau back-arc basin and results suggest a different hydrothermal convection scheme than axial hydrothermal systems. Major hydrothermal activity is predicted to occur at topographic highs due to significant fluid migration along inferred basement topography off-axis with associated permeability differences. Major hydrothermal fluid discharge occurs at off-axis topographic elevated positions with temperatures (150°C - 450°C) and exit fluid velocities (4 m/s), in good agreement with seafloor observation and theoretical calculations. Heuristic mass calculations pertaining to the formation of massive sulfide deposits imply that a significant base metal sulfide deposit (5 Mt at 10% Cu + Zn) may form in less than 6,000 years, assuming a fluid containing a maximum of 10 ppm base metals and a deposition efficiency of 10 percent. The size and distribution patterns of massive sulfide deposits are determined primarily by fault distribution, provided that adequate fluid flow pathways and heat supply exist.

This article has been cited by other articles:

				J. Yang, R. R. Large, S. Bull, and D. L. Scott Basin-Scale Numerical Modeling to Test the Role of Buoyancy-Driven Fluid Flow and Heat Transfer in the Formation of Stratiform Zn-Pb-Ag Deposits in the Northern Mount Isa Basin Economic Geology, September 1, 2006; 101(6): 1275 - 1292. [Abstract] [Full Text] [PDF]