 I'd like to welcome to the stage Jessica Lowchak from the ANU College of Science and the title of her presentation tonight is Mud and Molten Cocktails. Down it goes, deep into the earth, one billion tons of mud is lost from the surface of the earth each year. So what does one billion tons of mud look like? Well, imagine a glass of champagne, now forget the champagne, fill the glass with mud. Now do this to a row of champagne glasses, stretching from my hand to the sun. This is how much mud is lost each year, mud. Who cares, right? This much mud is lost each year, why do the continents still exist? This is where my research comes in. I want to know what happens to the mud deep below. Is it lost forever or does it come back up to the surface somehow? When two tectonic plates collide, mud is pushed deep into the mantle, 100 kilometers beneath our feet. The pressures and temperatures in the mantle are so immense that the mud is squished and melted to form a cocktail of molten rock. This molten cocktail, rich in elements, has a base of silica with a dash of alumina and a spritz of strontium, rubidium and thorium. How do I know this? I'm a purveyor of fine cocktails. I melt mud under these extreme conditions in the comfort of a lab, of course. I do this by putting mud into tiny little capsules. I then place this into an apparatus. So what do my results show? When this molten cocktail is pushed deep down below, it moves up through the mantle, driven by buoyancy, much like bubbles in a glass of champagne, except on a much slower timescale. Some of the cocktail is absorbed by the mantle to make new crystals. However, some of the cocktail survives and pushes its way up to the surface of the earth where, boom, it erupts in a volcano. I'm studying a particular part of this process called mantle metasemitism. Over thousands of years, erupted rock will be turned back into mud and washed into the oceans of tomorrow so that the cycle can begin again. But more importantly, the mud that was once lost is returned back to the surface so that the cocktail party, much like the recycling of our continents, never ends.