Our group studies the geochemical and climatic evolution of Earth using a combination of experimental and theoretical (modeling) approaches. His previous work has focused on measuring and modeling small variations in isotope ratios of a range of elements (e.g. ¹³C/¹²C, ¹⁸O/¹⁶O, ¹⁵N/¹⁴N, ²⁶Mg/²⁴Mg, ⁴⁰Ar_ATM) in marine sediments, pore-fluids, and ice cores. At Princeton, Higgins has set up a new analytical laboratory capable of state-of-the-art measurements of isotope ratios of Mg, Ca, Li, Sr, Si, and B in a range of natural samples. The Higgins group pursues questions ranging from the geochemistry of hydrothermal water-rock interactions and carbonate sediments to the processes that drive variations in atmospheric CO₂ on million year timescales and regulate the oxygen content of Earth’s atmosphere and determine the chemistry of its oceans. Below are a few photographs from our research.