moved in and out of the hydrothermal vent environment over time? Fossilization of organisms is a
selective process that does not preserve all the fauna
that are present at vents. Identification of fossils at
the species level is often difficult, especially where
microbes are concerned. Notwithstanding, it is important to search for more examples of ancient fossil
assemblages and to trace the fossil record of life at
hydrothermal vents back as far as possible to shed
light on how vent communities have evolved, and
whether life on earth might have originated at submarine hydrothermal vents.
Summary
Formation of hydrothermal deposits is an integral
aspect of seafloor accretion at mid-ocean ridges.
These deposits are valuable for their metals, for the
role that they play in fostering hydrothermal vent
ecosystems, for the clues that they hold to understanding spatial–temporal variability in hydrothermal vent systems, and as geologic records of how
life at hydrothermal vents has evolved. From these
deposits we may gain insights about biogeochemical
processes at high temperatures and pressures that can
be applied to understanding life in inaccessible
realms within the earth’s crust or on other planetary
bodies. We are only beginning to unravel the complexities of ridge hydrothermal vent deposits. Much
exploration and interdisciplinary study remains to be
done to obtain the valuable information that they
contain.
See also
Hydrothermal Vent Fluids, Chemistry of. MidOcean Ridge Geochemistry and Petrology.
Further Reading
Dilek Y, Moores E, Elthon D, and Nicolas A (eds.) (2000)
Ophiolites and Oceanic Crust: New Insights from Field
Studies and the Ocean Drilling Program. Geological
Society of America Memoir. Boulder: Geological Society
of America.
Haymon RM (1989) Hydrothermal processes and products
on the Galapagos Rift and East Pacific Rise, 1989.
In: Winterer EL, Hussong DM, and Decker RW (eds.)
The Geology of North America: The Eastern Pacific
Ocean and Hawaii, vol. N, pp. 125--144. Boulder:
Geological Society of America.
Haymon RM (1996) The response of ridge crest
hydrothermal systems to segmented, episodic magma
supply. In: MacLeod CJ, Tyler P, and Walker CL (eds.)
Tectonic, Magmatic, Hydrothermal, and Biological
Segmentation of Mid-Ocean Ridges, vol. Special
Publication 118, pp. 157--168. London: Geological
Society.
Humphris SE, Zierenberg RA, Mullineaux LS, and
Thomson RE (eds.) (1995) Seafloor Hydrothermal
Systems: Physical, Chemical, Biological, and Geological
Interactions, Geophysical Monograph, vol. 91.
Washington, DC: American Geophysical Union.
Little CTS, Herrington RJ, Haymon RM, and Danelian T
(1999) Early Jurassic hydrothermal vent community
from the Franciscan Complex, San Rafael Mountains,
California. Geology 27: 167--170.
Tivey MK, Stakes DS, Cook TL, Hannington MD, and
Petersen S (1999) A model for growth of steep-sided
vent structures on the Endeavour Segment of the Juan
de Fuca Ridge: results of a petrological and geochemical
study. Journal of Geophysical Research 104:
22859--22883.
380 HYDROTHERMAL VENT DEPOSITS
selective process that does not preserve all the fauna
that are present at vents. Identification of fossils at
the species level is often difficult, especially where
microbes are concerned. Notwithstanding, it is important to search for more examples of ancient fossil
assemblages and to trace the fossil record of life at
hydrothermal vents back as far as possible to shed
light on how vent communities have evolved, and
whether life on earth might have originated at submarine hydrothermal vents.
Summary
Formation of hydrothermal deposits is an integral
aspect of seafloor accretion at mid-ocean ridges.
These deposits are valuable for their metals, for the
role that they play in fostering hydrothermal vent
ecosystems, for the clues that they hold to understanding spatial–temporal variability in hydrothermal vent systems, and as geologic records of how
life at hydrothermal vents has evolved. From these
deposits we may gain insights about biogeochemical
processes at high temperatures and pressures that can
be applied to understanding life in inaccessible
realms within the earth’s crust or on other planetary
bodies. We are only beginning to unravel the complexities of ridge hydrothermal vent deposits. Much
exploration and interdisciplinary study remains to be
done to obtain the valuable information that they
contain.
See also
Hydrothermal Vent Fluids, Chemistry of. MidOcean Ridge Geochemistry and Petrology.
Further Reading
Dilek Y, Moores E, Elthon D, and Nicolas A (eds.) (2000)
Ophiolites and Oceanic Crust: New Insights from Field
Studies and the Ocean Drilling Program. Geological
Society of America Memoir. Boulder: Geological Society
of America.
Haymon RM (1989) Hydrothermal processes and products
on the Galapagos Rift and East Pacific Rise, 1989.
In: Winterer EL, Hussong DM, and Decker RW (eds.)
The Geology of North America: The Eastern Pacific
Ocean and Hawaii, vol. N, pp. 125--144. Boulder:
Geological Society of America.
Haymon RM (1996) The response of ridge crest
hydrothermal systems to segmented, episodic magma
supply. In: MacLeod CJ, Tyler P, and Walker CL (eds.)
Tectonic, Magmatic, Hydrothermal, and Biological
Segmentation of Mid-Ocean Ridges, vol. Special
Publication 118, pp. 157--168. London: Geological
Society.
Humphris SE, Zierenberg RA, Mullineaux LS, and
Thomson RE (eds.) (1995) Seafloor Hydrothermal
Systems: Physical, Chemical, Biological, and Geological
Interactions, Geophysical Monograph, vol. 91.
Washington, DC: American Geophysical Union.
Little CTS, Herrington RJ, Haymon RM, and Danelian T
(1999) Early Jurassic hydrothermal vent community
from the Franciscan Complex, San Rafael Mountains,
California. Geology 27: 167--170.
Tivey MK, Stakes DS, Cook TL, Hannington MD, and
Petersen S (1999) A model for growth of steep-sided
vent structures on the Endeavour Segment of the Juan
de Fuca Ridge: results of a petrological and geochemical
study. Journal of Geophysical Research 104:
22859--22883.
380 HYDROTHERMAL VENT DEPOSITS