Dr. Schedl’s Research:
Research is focused on studying meteorite impacts on Earth and Mars. The goal of meteorite impact studies on Mars is to understand the origins of large landslides, >500 km2, landslides in Valles Marineris. Valles Marineris is a canyon almost 3500 km long (the distance from NYC to LA), six times wider than the Grand Canyon and locally as deep the height of Mount Everest. Research is now shifting to using meteorite impacts to try to understand the origins of Valles Marineris itself.
On Earth, impact studies are aimed at identifying meteorite impact craters. In the flat lying rocks of the stable interior of the United States, where one finds circular deformed structures the usual evidence of meteorite impact, shatter cones and shocked minerals, e. g., quartz, are absent. Here the rocks are limestone and dolostone. We are applying a new approach to identifying impact craters, calcite-twin analysis. Recently, we have shown using calcite-twin analysis that the Jeptha Knob structure, Kentucky, formed ≈450 Ma when a meteorite smashed into a shallow sea. The heat generated by impact created a hydrothermal system (hot circulating seawater) that converted a volume at least 2 kilometers in diameter and .75 kilometers deep from limestone into dolomite. Post meteorite impact mineralization obliterated conventional evidence of meteorite impact. Between 470 to 440 Ma there was an uptick in the number of meteorite impact craters on Earth probably due to the collision of two 100 km diameter asteroids in the Asteroid Belt and Jeptha Knob was part of this uptick.