During the past ten years, evidence has developed to indicate that
seawater convects through oceanic crust driven by heat derived from
creation of lithosphere at the Earth-encircling oceanic ridge-rift
system of seafloor spreading centers. This has stimulated multiple lines
of research with profound implications for the earth and life sciences.
The lines of research comprise the role of hydrothermal convection at
seafloor spreading centers in the Earth's thermal regime by cooling of
newly formed litho- sphere (oceanic crust and upper mantle); in global
geochemical cycles and mass balances of certain elements by chemical
exchange between circulating seawater and basaltic rocks of oceanic
crust; in the concentration of metallic mineral deposits by ore-forming
processes; and in adaptation of biological communities based on a
previously unrecognized form of chemosynthesis. The first work- shop
devoted to interdisciplinary consideration of this field was organized
by a committee consisting of the co-editors of this volume under the
auspices of a NATO Advanced Research Institute (ARI) held 5-8 April 1982
at the Department of Earth Sciences of Cambridge University in England.
This volume is a product of that workshop. The papers were written by
members of a pioneering research community of marine geologists,
geophysicists, geochemists and biologists whose work is at the stage of
initial description and interpretation of hydrothermal and associated
phenomena at seafloor spreading centers.