| dc.description.abstract | Microbial mats are layered, surface-attached communities of microorganism that live under stagnant or moving bodies of water. Active precipitations of minerals often occur around these spatially arranged communities, forming rough, conical or domal surfaces. These surfaces are considered Earth’s oldest and most robust fossil signatures of life whenever microfossils are unattainable. Despite decades of investigation, the formation mechanisms of these shapes remain vaguely explained. It was hypothesized though, that nutrient limitation coupled with fluid motion may play a key role as a physical control. Under this model, competitions of nutrients were setup among growing microbial communities, which later evolve into specially arranged, 3D mats. However, this hypothesis seems to require an initial condition, a template of early topographical randomness for the physical mechanisms to kick in. This initial surface was observed in laboratory grown mats, but its physical role was never investigated. For this research, an innovative modeling approach was employed that focuses on the interface growth of the microbial mat surfaces using a combined stochastic and deterministic approach. A range of different initial conditions were simulated to evaluate the 3D topography evolution. This method directly assists the experimental work on mats growth, and allows a more robust test of the possible biological mechanisms that exist in forming various surfaces in the rock record, thus offering a better interpretation. | en |
