Summary: Stromatolites are layered structures built by the buildup of chemical sediment under the influence of microbial communities. Hundreds of stromatolite forms have been identified, most of them in Proterozoic-aged rocks. During the Proterozoic, observed morphologies include flat-laminated, domal, columnar, branching columnar and conical, across scales from a few centimeters to tens of meters. Furthermore, the middle Proterozoic era (~1300-1000 Ma) records the highest diversity of stromatolite forms, with fewer forms recognized in older and younger successions. Although it is well known that stromatolites result from the interaction of microbial communities, detrital sediment, and carbonate precipitation, the controls on stromatolite morphology are surprisingly less well-understood.  This presentation explores how macroscopic stromatolite morphology can best be understood as lamina form expressed over time. Because stromatolite laminae represent an active growth surface at the time of formation, they therefore record the topography of the depositional surface, reflecting the interactions between the emergent stromatolite and its environment. This "lamina-upward" approach to morphological analysis provides a useful tool for explaining the complexity and diversity of stromatolite form through Earth history.

Biography: TBD