CAREER: Developing New Methodologies to Investigate the Thermal, Tectonic, and Climatic History of Continental Settings - An Integrated Educational and Research Project

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

For over two decades it has been assumed that transport properties for both heat and helium are similar in the crust and that transport for both tracers is in steady-state. In addition, the presence of a terrestrial helium-heat imbalance was suggested based on the observed low mantle He/heat flux ratio at the proximity of mid-ocean ridges. Recent work, however, indicates that the driving transport mechanisms for these two tracers are of a fundamentally different nature for a high range of rock permeabilities in the crust. It was concluded that low He/heat flux ratios in a steady-state regime do not reflect a He deficit in the crust or mantle original reservoirs, but rather, the combined impact of air saturated water, advection, conduction, and diffusion. Together with other noble gas measurements and determined noble gas temperatures (NGTs), part I of the proposed work will take advantage of these recent findings to test and develop the newly created He/heat flux tracer to identify the occurrence, both in time and space, of tectonothermal events in continental regions, and in the Michigan Basin in particular. Part II will take advantage of common tools in order to address questions in relation to NGT determination in ice-covered regions. The latter is a direct measure of the temperature at which groundwater equilibrated with the atmosphere during infiltration and offer a unique opportunity to improve our understanding of past climate in continental areas as well as to assess the impact of glaciation on groundwater recharge in mid-high latitude regions. In addition to illustrating how He/heat flux ratios can be used in conjunction with NGTs to investigate the tectonothermal history of continental regions, this work will also contribute to an improved understanding of NGT determination in ice-covered regions. This work will impact knowledge in the fields of Mantle Geochemistry, Geophysics, Structural Geology, Hydrology and Paleoclimatology. This research will be the basis of a new, exclusively research-oriented undergraduate course. Identifying problems to be addressed, collecting and analyzing data, testing hypotheses, reaching potential conclusions and writing the prototype of a scientific paper will be an integral part of this class. Of particular relevance is the participation of undergraduate non-science majors, in particular women and underrepresented groups into scientific discovery, which is expected to captivate students and ultimately draw increasing numbers into a scientific career.