Dr. McDonough's Homepage

Our Research into Geochemistry - Deep Earth

Deep Earth geochemistry involves studies of the mineralogical and chemical composition of the silicate and metallic shells of Earth’s interior. Our approach includes the analyses of natural samples and experimental run products of analog compositions. In addition, our research group is involved in calculating and testing theoretical models of the planet, the core, and the silicate Earth. These studies help to inform our models of how the Earth was assembled and differentiated. Moreover, the various competing compositional models of the Earth differ widely and predict different amounts of radiogenic power in the Earth and different mineralogical proportions for the bulk of the lower mantle. Thus a fundamental goal in Earth Sciences is to test the consistency of such geochemical models with a wide range of geological, geophysical, geochemical and meteoritical observations.

Our research into Geochemistry - Lithosphere

The lithosphere is the outermost conductive thermal boundary layer of the Earth, including the crust and lithospheric mantle for both the oceanic and continental environment. Studies show that the lithospheric mantle beneath the continents is old, refractory and markedly different from the asthenosphere and lithospheric mantle beneath the oceans. Old cratonic areas are underlain by old cratonic lithospheric mantle. We are involved in chemical and isotopic analyses of samples of the crust and mantle as ways to inform our understanding of the composition and formational processes (including long term stability) of these regions. In addition, a major goal of our research is to characterize the 3-D spatial distribution of the elements in the lithosphere as these data inform models of when, how and through what processes it formed. Moreover, specifying the amount and distribution of K, Th and U, the heat producing elements, constrains models of heat production in the lithosphere and lateral differences in the Earth’s geoneutrino flux.

Our Research into Geochemistry - Enviromental

Chemical reactivity at the Earth’s surface is a rich rewarding field of research. Our group has been involved in marine and terrestrial sited research topics that inform us about surface evolutionary processes. Weathering of the continents has occurred throughout Earth’s history and has varied in style as a function changing atmospheric conditions and global glacial cycles. We are studying the composition of average surface samples to examine temporal and spatial variations and interpret how these reflect the chemical evolution of the Earth’s upper continental crust.

Geochemistry, Solid Earth, Deep Earth publications

Geochemistry, Solid Earth, Lithosphere Publications

Geochemistry Enviromental Publications