Current Research:

Research Interests:

Petrogenesis of mid-ocean ridge basalts (MORB) and island arc lavas and plutons; Relationships between tectonics and magmatism; Segment-scale chemical variations in MORB; Off-axis and near-ridge seamount volcanism; Temporal variability in MORB chemistry; Development of island arcs; Ridge-hotspot and ridge-trench interactions, the origin and diversification of magmas from oceanic spreading centers and island arcs; in particular, trace element, isotopic and phase chemical studies to determine the sources and processes involved in magma genesis; structural and tectonic controls on the development of seamounts and spreading centers; geochemistry and petrology of subduction zone igneous and metamorphic rocks.

I have had extensive experience in mapping and sampling mid-ocean ridges and a few island arcs. In my marine research I utilize the submersible Alvin, a number of different remotely operated vehicles (ROVs), and towed camera and side-scan sonar sleds. In my labs I have petrographically and geochemical analyzed oceanic rocks from the East Pacific Rise, Cayman Trough, Galapagos Spreading Center and the Juan de Fuca Ridge. These analyses have provided significant understanding of volcanism and petrogenesis at ridges and provides critical information about the construction of oceanic lithosphere.