Figure 7.

Changes in temperature and sulfide with depth in background and hydrothermal sediments. Relative to background sediment distal from venting (+), the (a) temperature increases with depth and toward the center of the vent features from gray sediments fringing the hydrothermal sites (▲), to the white patches (□) and orange/yellow precipitates (◆). The precipitates in Rocky Point and Spiegelei were both orange and those in Twinkie (symbol marked with ‘*’) were yellow in color. (b) Dissolved H₂S concentrations also increase with depth in the gray and white sediments but are lowest in the yellow areas. Paired temperature and sulfide measurements in Twinkie and Spiegelei were made at 5 cm (the upper sediments) and 15 cm (lower sediments). Data from Rocky Point were measured at sediment depths of 10 cm and 20 cm.