Rocks that have been totally altered by hot (hydrothermal) fluids. Their
original minerals are now completely replaced by different minerals, often much
lighter in color.
Image ID: expl1833, Voyage To Inner Space - Exploring the Seas With NOAA Collect Location: New Zealand, Kermadec Arc Photo Date: 2005 May 9 Credit: New Zealand-American Submarine Ring of Fire 2005 Exploration; NOAA Vents Program