Plate tectonics revolutionized the field of geology (and contributed largely to other fields as well such as biology).  Yet, the theory raised as many questions as it answered.  In particular, we still struggle to understand when, how and why continents deform.  Plate tectonics predicts deformation to occur primarily on the margins of continents due to two or more plate interacting, but in actuality, deformation occurs elsewhere on continents.  This project addressed one aspect of this puzzle: the formation of thickened portions of continents.  

The thickened regions of continents, called cratons, are not only scientifically intriguing.  They are also regions of economic significance (these are also the areas where diamonds are found) and societal importance due to their tectonic stability.  Cratons have not experienced major tectonic activity (i.e., earthquakes, volcanic eruptions,etc.) since their formation about 2-3 billion years ago.  What makes these regions so stable?  Short answer is, in large part, their thickness.  This project expanded our knowledge of what it takes to build thick stable regions on the Earth.  

It also highlighted a much speculated, but largely not well understood secondary process that might be a necessary step in making cratons.  Previous ideas did not prove viable using known Earth materials - often, the material proposed to make cratons proved too dense to thicken without sinking.  My graduate student and I demonstrated a way to remove dense material while still making a thick & stable continent.  We also showed that some of the dense material can remain depending on how much of it existed as well as the strength of the surrounding material.  

This project also spurred a new collaboration with a seismologist and provided context for new images of the deep interior of continents.  We suggested that the anomalous features that seismologists keep finding the more they peer into continents might be relics or scars from the formation of the thick regions.  

Finally, beyond the bounds of science, the largest impact of this project is the training and support that it provided for women.  As mentioned previously, the project supported the training of a young, female graduate student.  She obtained computational skills and a background in fluid dynamics, heat transfer and material deformation.  This has allowed her to easily transition into a career in the geothermal industry.  In addition, this project help the PI obtain tenure and promotion - a critical juncture in the academic pipeline.  This helped keep the PI in academia as well as place her in a higher position within a large, research university.  Both of these impacts are critical if we wish to change the tapestry of the STEM fields. 

Last Modified: 08/04/2015
Modified by: Catherine Cooper