primarily involved scientists from Scripps. These studies allowed us to define the
ridge axis and have a broad understanding of the topography of the area.
The French team headed by Jean Francheteau included David Needham from
IFREMER, Thierry Juteau (University of Strasbourg) and Claude Rangin (University Pierre-Marie Curie, Paris 7). The French team was to be the first on the site
in the summer of 1978 with the diving saucer Cyana and its support ship Le Nadir.
The cruise was called ‘‘Cyamex’’ for CYAna—MEXico, since the dives were to
take place in the Mexican economic zone. Scientists from a Mexican University
were also invited to participate in the dives.
A total of 22 dives were performed of which twelve were located along
the ridge axis and ten were perpendicular to the axis on the flank of the ridge. The
main goal of the dives was to understand how the lava morphology and the
tectonics of a fast spreading ridge differed from those of a slow spreading ridge
segment. Were recent eruptive events more abundant at a fast spreading ridge, and
was the creation of the crust more extensive? What are the relationships between
lava types and the styles of eruption in relation to spreading rates?
After the CYAMEX cruise of 1978, another sea-going expedition conducted by
U.S. scientific teams took place in November 1979 with the R.V. Gilles from
southern Florida (Rosenthal School of Oceanography) and the catamaran Lulu,
which carried the submersible Alvin from the Woods Hole Oceanographic Institution (Fig. 7.14). The R.V. Gilles essentially served as a back-up ship for hosting
the scientific team that was scheduled to dive with Alvin.
I did not participate with the French team, because the chief scientist, Jean
Francheteau, had decided to involve a land-trained petrologist, Thierry Juteau. The
logic behind his choice was that a land geologist might view the sea floor differently. However, in 1979, I was invited by the U.S. team headed by Harmon
Craig to participate on their diving cruise with the submersible Alvin at the site of
the CYAMEX project. Another French scientist invited to participate on the cruise
was Francis Albarede, a geochemist from the Institute de Physique du Globe (IPG)
in Paris.
John Edmond and Harmon Craig were both geochemists working at MIT and
Scripps Institution of Oceanography, respectively. They were the Principal
Investigators (PI’s) of the project. The chief scientist of the cruise was Harmon
Craig. Water chemists, Chris Measure and Karen Von Damm, from MIT (Massachusetts Institute of Technology in Boston, USA) were also involved. Karen did
comprehensive work on the hydrothermal fluid samples collected during the
expedition, which served as her Ph.D. thesis published in 1983. This was the first
contribution made from field experience concerning hydrothermal fluid circulation
on the sea floor.
The R.V. GILLIS was poorly equipped for mapping since it only had a singlechannel depth sounder. Francis Albarede took charge of the dredging stations that
we had to carry out in the evening after seven o’clock when the Alvin was no
longer on the bottom. Also, in 1979, navigation fixes were not as accurate as they
are today. In order to locate the sample sites (stations) while we were in the
submersible, it was necessary to take fixes with the Lulu, which was positioned
200
7 Oceanic Spreading Ridges and Sea Floor Creation
ridge axis and have a broad understanding of the topography of the area.
The French team headed by Jean Francheteau included David Needham from
IFREMER, Thierry Juteau (University of Strasbourg) and Claude Rangin (University Pierre-Marie Curie, Paris 7). The French team was to be the first on the site
in the summer of 1978 with the diving saucer Cyana and its support ship Le Nadir.
The cruise was called ‘‘Cyamex’’ for CYAna—MEXico, since the dives were to
take place in the Mexican economic zone. Scientists from a Mexican University
were also invited to participate in the dives.
A total of 22 dives were performed of which twelve were located along
the ridge axis and ten were perpendicular to the axis on the flank of the ridge. The
main goal of the dives was to understand how the lava morphology and the
tectonics of a fast spreading ridge differed from those of a slow spreading ridge
segment. Were recent eruptive events more abundant at a fast spreading ridge, and
was the creation of the crust more extensive? What are the relationships between
lava types and the styles of eruption in relation to spreading rates?
After the CYAMEX cruise of 1978, another sea-going expedition conducted by
U.S. scientific teams took place in November 1979 with the R.V. Gilles from
southern Florida (Rosenthal School of Oceanography) and the catamaran Lulu,
which carried the submersible Alvin from the Woods Hole Oceanographic Institution (Fig. 7.14). The R.V. Gilles essentially served as a back-up ship for hosting
the scientific team that was scheduled to dive with Alvin.
I did not participate with the French team, because the chief scientist, Jean
Francheteau, had decided to involve a land-trained petrologist, Thierry Juteau. The
logic behind his choice was that a land geologist might view the sea floor differently. However, in 1979, I was invited by the U.S. team headed by Harmon
Craig to participate on their diving cruise with the submersible Alvin at the site of
the CYAMEX project. Another French scientist invited to participate on the cruise
was Francis Albarede, a geochemist from the Institute de Physique du Globe (IPG)
in Paris.
John Edmond and Harmon Craig were both geochemists working at MIT and
Scripps Institution of Oceanography, respectively. They were the Principal
Investigators (PI’s) of the project. The chief scientist of the cruise was Harmon
Craig. Water chemists, Chris Measure and Karen Von Damm, from MIT (Massachusetts Institute of Technology in Boston, USA) were also involved. Karen did
comprehensive work on the hydrothermal fluid samples collected during the
expedition, which served as her Ph.D. thesis published in 1983. This was the first
contribution made from field experience concerning hydrothermal fluid circulation
on the sea floor.
The R.V. GILLIS was poorly equipped for mapping since it only had a singlechannel depth sounder. Francis Albarede took charge of the dredging stations that
we had to carry out in the evening after seven o’clock when the Alvin was no
longer on the bottom. Also, in 1979, navigation fixes were not as accurate as they
are today. In order to locate the sample sites (stations) while we were in the
submersible, it was necessary to take fixes with the Lulu, which was positioned
200
7 Oceanic Spreading Ridges and Sea Floor Creation