Geology of a hydrothermal upflow zone on the Endeavour Segment, Juan de Fuca Ridge

Abstract

The upflow zone on the Endeavour Segment, Juan de Fuca Ridge, represents an extinct hydrothermal system that was raised up by faulting, exposing the interior. Submersibles and remotely operated underwater vehicles were used to explore the area and collect still images, video, and rock samples from the area. The rock samples were examined to determine which minerals were present and where they had been altered by the hydrothermal fluids. The video and still images were examined to determine where different types of geological features were present and to create a map of these features. The results suggest that chimneys were built but remained relatively small and the area covered by hydrothermal sediments was also very small.