 Hi my name is Karen Block and I am a geochemist and petrologist at the City College of New York. As a geochemist I like to study how materials move between different portions of the earth. So for example the lithosphere, the biosphere, the hydrosphere, and the atmosphere. Some of the work that I do involves how microbes react to the minerals that they are accumulated with in the environment and how the materials that the microbes produce change in response to the minerals that are in their proximity. At the same time the minerals then change their structure in response to that interaction with organic matter. This is very important for studies of climate change where we are concerned with how much carbon is stored in places like the terrestrial ecosystems. So in other words soils. I also have studied how viruses interact with clay minerals and how clay minerals can inactivate viruses in the environment. Something that's become very important right now with the study of environmental viruses such as COVID that can persist out here in the natural world for long periods of time. But we have also looked at how some of those aggregation dynamics between minerals and microbes actually serve to preserve viruses for very long periods of time when they are deposited and sequestered away for example in lakes and ponds. So these are some of the things that I like to look at. I hope that you found that interesting and that you will learn more about geochemistry.