THE QUANTUM EVENT OF OCEANIC CRUSTAL ACCRETION - IMPACTS OF DIKING ATMIDOCEAN RIDGES

Seafloor diking-eruptive events represent the irreducible, quantum eve nts of upper oceanic crustal accretion. They record events by which a targe portion of the oceanic crust has formed through geological histo ry. Since 1993, the U.S. Navy's real-time Sound Surveillance System ha s allowed Location of ongoing acoustic signatures of dike emplacement and basalt eruptions at ridge crests in the northeast Pacific. These d iking-eruptive events trigger a sequence of related, rapidly evolving physical, chemical, and biological processes. Magmatic volatiles relea sed during these events may provide nutrients for communities of subse a-floor microorganisms, some of which thrive in high-temperature anaer obic environments. Many of the organisms identified from these systems are Archaea. if microorganisms can thrive in the wafer-saturated pore s and cracks within deep, volcanically active portions of our plane's, other hydrothermally active planets may harbor similar life forms.