Ted Present

Ted is a research scientist with sedimentology and geochemistry experience in a range of modern and ancient environments. He works to understand what controls planetary surface environments and how it has shaped life. He is developing x-ray fluorescence and mass spectrometry techniques for reconstructing ancient surface and pore water compositions and the biogeochemical processes driven by microbial communities in those waters. As project lead for the "Terrestrial analog studies of magnesium carbonates at Jezero Crater, Mars," he is designing and steering field and laboratory studies of magnesite-bearing serpentinites and related soils and sedimentary units in Australia to better understand similar deposits currently being explored by the 2020 Mars Rover. These data and tools enable searching for chemical and physical signatures of microbial carbon and sulfur cycling. This projects builds on his postdoc work studying (1) modern tidal basins on Little Ambergris Cay, Turks and Caicos, where widespread microbial mats govern sedimentary dynamics but quickly decay, leaving little physical trace of their influence; (2) middle Paleoproterozoic evaporitic marine 'shoreline tufas' in the Pethei Group, Northwest Territories, Canada whose complicated but well-organized geometry reflects the interplay of physical, chemical, and biological processes; and (3) late Ediacaran peritidal carbonates and paleokarsts in subsurface cores from the South Oman Salt Basin. These projects inform terrestrial and Martian carbon budgets, soil and atmospheric composition, and weathering changes through time.