Investigating an impact origin for Hadean zircons from Western Australia
Required AvailabilitySpring 2017
Course Credit?Yes - Geo 399/499
Hadean zircons, found in the Jack Hills, Western Australia, are the oldest known materials on Earth, dating back to nearly 4.4 Ga or only ~150 Ma after formation. These tiny grains have been essential in transforming our view of the Hadean from a hot, hellish environment to one that appears much more hospitable to life with continental crust, water, and possibly even plate tectonics. Understanding the magmatic environment that leads to the formation of these ancient grains is fundamental to interpreting the geochemical signatures within them. Hypothesis of formation environments have ranged from plate boundary interactions to impact melt sheets. One important characteristic of the Jack Hills zircons is their unique inclusion assemblage, dominated by muscovite and quartz. This project will investigate, via Electron Probe Micro Analysis (EPMA), the inclusion population of zircons formed in four of the largest terrestrial impact craters to compare to that of the Jack Hills grains to explore a possible impact origin of the Hadean Jack Hills zircons.