2011 Annual Science Report

University of Hawaii, Manoa Reporting  |  SEP 2010 – AUG 2011

Measurements of Primitive Water

Project Summary

Our research goal is to collect and analyze water that may sample the primordial water accreted by the Earth. This primordial water may reside at the bottom of the Earths mantle and may be sampled from “hotspot” volcanism such at that occurring in Iceland and Hawaii. Glass melt inclusions inside olivine crystals that formed at depth before the lava interacted with surface waters give us the best chance to find this primordial water.

4 Institutions
3 Teams
0 Publications
1 Field Site
Field Sites

Project Progress

“D/H Measurements in Samples from Mantle Hotspots”

Work has continued on samples from the Hawaiian deep drill core towards our CAN-5 research goal to collect and analyze D/H measurements in samples from mantle hotspots. A new protocol to eliminate adsorbed water from the sample was put in place, and a second round of measurements were completed in March 2011. One of the samples proved particularly interesting, with the melt inclusions in olivine containing H with δD ~90‰ lower than the surrounding olivine, and the lava surrounding the olivine showing δD ~40‰ lower than the olivine. The project was delayed while Kim Binsted was in Canada working on a different project, but she is back now and has documented a new set of samples. We will be making more measurement in a few weeks to follow up on this discovery. Last year, we showed that the Iceland samples we had in hand were not suitable for the isotopic measurements. Late this summer, a team including Karen Meech and Thor Thordarson collected some new samples for this work.

We have obtained additional samples of picrites in the Thingvellier region of Iceland during August 2011 prior to the workshop held there on the Origin of Earth’s water. Our goal was to get some samples that had not degassed, and selected a site that had erupted sub-glacially.

Team member Thorvaldur Thordarson sampling primitive lavas at a site in Iceland.