Research Training Program

Brittany Meagher
University of California Riverside
Riverside, California

Jim Luhr, Ph.D.
Supervising Scientist
Department of Mineral Sciences

"Spending my summer participating in RTP has been one of the most enriching experiences I have ever had."

Looking South of Iceland Through Volcanic Glasses

Iceland has been hypothesized to not only be a hot spot but also a wet spot. Geologic hot spots are places where a column of upwelling hot rock, known as a plume, rises from deep in the mantle toward the Earth's surface. If Iceland was also a wet spot it would mean that water contents of Mid Ocean Ridge Basalts (MORBs) would increase as Iceland is approached along the Mid-Atlantic Ridge from the south. To test this hypothesis twenty-eight samples were obtained from the Smithsonian Sea-Floor Glass Collection. The majority of these samples run along the Reykjanes Ridge just south of Iceland. These samples were analyzed for H2O (water) using Fourier Transform Infrared Spectroscopy. Upon analyzing the results of this method, it was found that H2O (water) increases as Iceland is approached from the South along the Reykjanes Ridge. Similar increases can also be seen in the abundances of K2O (potassium oxide)and P2O5 (phosphorus pentoxide). This is what was expected to be found since K (potassium), H (hydrogen), and P (phosphorus) are all incompatible elements in basaltic systems. One way to explain this increase in incompatible elements is to argue that there is a lower percent of melting happening beneath Iceland compared to the southern Reykjanes Ridge. However, since Iceland is known to be a very active hot spot, where anomalously large volumes of magma have erupted, the idea of lowering the percent melting to provide an explanation for the large quantity of incompatible elements does not make sense. The logical alternative explanation is that the Icelandic hot spot must come from an enriched mantle source, in turn showing that Iceland is indeed not only a hot spot but also a wet spot.

This research was supported by a grant from the National Science Foundation Research Experiences for Undergraduates program, Award Number DBI-02435123.

Letter of gratitude