Reconstructing the nature of early life strongly depends on rare microfossils in the ancient rock record. Earth’s early oceans were silica-supersaturated, which led to precipitation of chert deposits that superbly preserved microbial cells. As we trace this record of life back in deep time, however, we encounter progressively deformed and carbonized microfossils of dubious origin.
TRACES will study the nano-scale transformations that occur when microorganisms are subjected to artificial silicification and thermal degradation. This will be compared with microfossils in ancient chert deposits. The critical question will be answered whether key types of fossilized life can be distinguished from each other, and from abiological artifacts, in the oldest, most altered part of the rock record.