Chemistry of Submarine Hydrothermal Solutions at 21 deg North, East Pacific Rise and Guaymas Basin, Gulf of California

摘要

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