Welcome to Assay Earth! 

We are here to help measure and understand whats under the surface by using geophysics and other scientific tools. 

​

Principal Lisl Lewis

I already loved geology, but got hooked on geophysics as a teenager when I learned that there can be a relationship between beautiful rocks and mathematical equations. This blew my mind!

 

I spent the first decade of my career out in the field doing mineral and geothermal exploration surveys across North America, then gravitated (get it?!) offshore to do experimental marine electromagnetic stuff. I was a founding member of a startup field geophysics company called A.G.O. (AOA Geomarine Operations) in 2002 which was later acquired by Schlumberger (SLB).  During those noughty years (and beyond) within the enormous company of SLB, I focused on juggling motherhood and fulltime global managerial roles while our young family moved around the world, from California to Norway and then England. My career with SLB enabled me to return to my roots in geology and applied earth science, and I got deeply involved with geothermal project consulting (GeothermEx) for several years before leaving in 2025 to start my new venture, Assay Earth.  I'm a field gal at heart with geophysical experience from the deserts of central Mexico to the Canadian Arctic to the North Pacific frigid waters offshore Japan, back and forth (and up and down) around the Atlantic, and most recently in Cornwall. 

​

I started Assay Earth because I realised the power of modern geophysics and the huge leaps in technology over the past five years, and its potential to substantially reduce exploration risk and cost. Modern geophysics allows much more accurate targeting of exploration drilling and sampling, which is therefore lower impact and also cheaper. I want to spread the love of applied science to the wider world so that we can make better decisions about using Earth's resources in a more sustainable and low impact way that serves future generations.  Thanks for finding us!