Hydrothermal mounds of the Galapagos Rift: Observations with DSRV Alvin and detailed heat flow studies

Journal Article · Mon Dec 10 04:00:00 EST 1979 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB084iB13p07467· OSTI ID:5576922

Williams, D L; Green, K; Andel, T H.V.; Herzen, R P.V.; Dymond, J R; Crane, K

Ranging in height from gentle hills of less than a meter to steep-sided giants of more than 20 m, the mounds of the Galapagos Rift are spectacular hydrothermal features. Their internal temperatures have been measured at up to 13 /sup 0/C above the bottom water temperature, and total heat flow (conducted plus convected) can be several hundred to several thousand times the normal oceanic values. Fluids, when they discharge from the mound, do so at a very slow rate and at temperatures probably quite near the bottom water temperature. The mounds are principally composed of iron silicates intermixed and incrusted with lesser amounts of manganese oxides. They are generally found in rows, in a uniformly sedimented area above faults or fractures in the crustal rocks which permit fluids to escape from a deep hydrothermal aquifer. The sediment blanket in some way alters the chemistry of the ascending thermal fluids and leads to the development of mounds. The mounds field, covering an area of at least 200 km/sup 2/ and consisting of thousands of individual mounds, is probably less than 300,000 years old; and many of the mounds may be only a few tens of thousands of years old or less.

• Research Organization: U.S. Geological Survey, Box 25046, Federal Center, Denver, Colorado 80225
• OSTI ID: 5576922
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 84:B13; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150202 -- Geology & Hydrology of Geothermal Systems-- Non-USA-- (-1989)
58 GEOSCIENCES
580500* -- Oceanography-- (1980-1989)
CHALCOGENIDES
EARTH CRUST
GEOLOGIC FAULTS
GEOLOGIC STRUCTURES
GEOTHERMAL RESOURCES
GEOTHERMAL SYSTEMS
HEAT FLOW
HYDROTHERMAL SYSTEMS
IRON COMPOUNDS
IRON SILICATES
MANGANESE COMPOUNDS
MANGANESE OXIDES
OCEANIC CRUST
OXIDES
OXYGEN COMPOUNDS
PACIFIC OCEAN
RESOURCES
RIFT ZONES
SEAS
SEDIMENTS
SILICATES
SILICON COMPOUNDS
SURFACE WATERS
TRANSITION ELEMENT COMPOUNDS