Are Earths oldest fossils just rocks after all?
NEW YORK: Using multi-coloured spray paint, researchers have shown how rock-structures similar to the ‘stromatolites’ that scientists think are among the earliest fossils on Earth can form in the absence of life. Stromatolites are chalky mounds built up of layers of microbial secretions and trapped sediments. Fossilised stromatolites discovered in Western Australia have been dated to 3.4 billion years ago, to the so-called Precambrian era. While some stromatolites contain features which strongly suggest that biology played a major role in their creation, others could conceivably have formed in the absence of life. Distinguishing between biological and “abiotic” stromatolites is an active area of research. Chance discovery The new study, detailed in the March issue of the journal Geobiology, is the first to convincingly show in the lab how stromatolite-like structures can form without help from microorganisms. “Numerical modelling studies have previously shown that laminated stromatolit
