Joann Cannon ’15



Project Title

Studying the Past Carbon Cycle with Fossil-Bound Organic Matter

My PEI summer internship in the Sigman Lab focused on developing a method for measuring the carbon isotopic ratios of organic matter trapped in planktonic foraminifera fossils from a tropical Atlantic sediment core using a mass spectrometer. Our goals were to better understand the carbon cycle over the past 800,000 years and to investigate how biological and chemical changes in the ocean affected past atmospheric carbon concentrations. Over the summer, I researched and collected a shallow North Atlantic sediment core from the Lamont-Doherty Core Repository and then extracted and sorted the different species of foraminifera fossils from the sediment. I cleaned the extracted foraminifera according to a pre-determined procedure and then prepared the samples for mass spectrometer analysis. I ran the samples in the mass spectrometer and analyzed the resulting carbon isotope ratios. I learned all the hands-on skills of how to process sediment core samples from beginning to end: obtaining a core, picking out the desired fossil species, cleaning and prepping the samples, analyzing them in a mass spectrometer, and interpreting the results. This internship has encouraged me to continue doing research on this topic for my senior thesis and to possibly pursue graduate studies in this field.

Internship Year


Project Category

Climate and Energy


Sigman Lab, Princeton University, Princeton, NJ


Daniel Sigman, Professor, Chemical and Biological Engineering