P.I.: Sinton Proposal Number: 98-11276 Institution: University of Hawaii Title: Eruptive history of the Western Volcanic Zone, Iceland The objective of this work is to determine the eruptive history of ~170 km of Mid-Atlantic Ridge exposed in the Western Volcanic Zone of Iceland by mapping of lava flows, determining their eruptive volumes and other characteristics including chemical composition. Detailed study of the products of single eruptions will determine the physical nature of eruptive vents, lava flow morphologies, fissure lengths, and eruptive volumes, as well as the chemical variations associated with these features. The combined data for all eruptions within the Western Volcanic Zone will constitute an unprecedented composite of the frequency, volumes, chemical variability and spatial distribution of volcanic eruptions occurring along a significant portion of mid-ocean ridge. The results will be used to infer the nature, size, and processes occurring in subvolcanic magma reservoirs for this slow spreading but high magma supply mid- ocean ridge.