Well, my specialty was Amazonian botanical exploration (medicinal plants) and spent four years in the Brazilian rain forests working on tropical disease leads. Not much money in that , so when I returned, I took my degrees in medicinal chemistry and pharmacognosy and retrained at Johns Hopkins School of Medicine in mass spectrometry, just as the field was beginning to take off. It's been a good 25-year run, lots of publications, though I don't get to publish much anymore. I work in early discovery research for a large pharmaceutical corporation. Sorry, I can't do geological dating, don't have the right equipment!