Chemistry of submarine hydrothermal solutions at 21 degree north, East Pacific Rise and Guaymas Basin, Gulf of California. Doctoral thesis

Technical Report · Mon Aug 01 04:00:00 EDT 1983

OSTI ID:6674972

Von Damm, K L

The chemistry of hydrothermal solutions at 21 north, East Pacific Rise and Guaymas Basin, Gulf of California was determined. In contrast to the 21 N systems where the solutions exit directly from basalt, the hydrothermal systems at Guaymas pass through and react with approximately 500 meters of sediment cover before they exit on the seafloor. At 21 N, four vent areas with a maximum temperature of 355 C were sampled and at Guaymas, ten vent areas with a maximum temperature of 315 C were sampled. The hot springs at both sites are black smokers. The 21 N solutions are acid (pH = 3.3-3.8, 25 C, 1 atm), reducing (H2S = 6.6-8.4 m moles/kg) and metal rich (Fe up to 2.4 m moles/kg). The Guaymas solutions are less acid (pH = 5.9, 25 C, 1 atm) and metal rich (Fe < 0.18 m moles/kg). The higher pH and extremely high alkalinity (2.8-10.6 meq/kg) at Guaymas can be attributed to dissolution of CaCO3 and thermal degradation of organic matter which occur in the sediment column. The high pH and alkalinity are responsible for the lower concentrations of the metals which form insoluble sulfides and these are probably deposted within the sediment cover. Quartz geobarometry implies a depth of reaction within the oceanic crust of 0.5-3.5 kms for the two areas; in agreement with the geophysical estimates for the 21 N site.

• Research Organization: Woods Hole Oceanographic Institution, MA (USA)
• OSTI ID: 6674972
• Report Number(s): PB-90-241837/XAB; WHOI--84-3; CNN: NSF-OCE-8020203; NSF-OCE-8118481
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
152001* -- Geothermal Data &amp; Theory-- Properties of Aqueous Solutions
ACID NEUTRALIZING CAPACITY
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
CHEMISTRY
DISSOLUTION
EARTH CRUST
ELEMENTS
ENERGY SYSTEMS
ENVIRONMENTAL TRANSPORT
FLUIDS
GEOBAROMETRY
GEOTHERMAL FLUIDS
GEOTHERMAL SYSTEMS
GULF OF CALIFORNIA
HOT SPRINGS
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
HYDROTHERMAL SYSTEMS
IRON
LEACHING
MASS TRANSFER
METALS
OCEANIC CRUST
ORGANIC MATTER
OXYGEN COMPOUNDS
PACIFIC OCEAN
PH VALUE
REDUCING AGENTS
RESERVOIR TEMPERATURE
SEAS
SEDIMENTS
SEPARATION PROCESSES
SULFIDES
SULFUR COMPOUNDS
SURFACE WATERS
THERMAL DEGRADATION
THERMAL SPRINGS
TRANSITION ELEMENTS
WATER CHEMISTRY
WATER SPRINGS