Paper No. 32-4
Presentation Time: 8:00 AM-5:30 PM
QUANTITATIVE ANALYSIS OF STROMATOLITE MORPHOMETRICS, PALEOPROTEROZOIC ROCKNEST FORMATION, CANADA
Stromatolites are sedimentary structures that are thought to form through the interaction of sedimentation, mineral precipitation, and microbial growth, often cited as the earliest physical evidence of life on Earth. Stromatolites grow by generating thin laminae that build upon each other to form a diverse array of macroscopic stromatolite morphologies recorded in the geological record. It has been proposed that the primary controls of stromatolite morphology include the rates of sedimentation, microbial mat growth, and mineral precipitation, all of which are modulated by the physical and chemical conditions of the ancient seafloor. However, the ways that these factors interact with each other to produce specific morphologies remain poorly understood from a quantitative perspective. Previous research has used stochastic growth equations from materials science literature such as the Kardar-Parisi-Zhang equation to model the formation and morphology of individual stromatolites, but these studies have not yet addressed the growth dynamics of a spatiotemporally robust group of stromatolites. We focus on the problem of large-scale stromatolite growth using the reaction-diffusion equations to model ionic diffusion across ancient microbial mats inferred for the Rocknest Formation. We will use X Ray Fluorescence to observe potential geochemical gradients that may be preserved across laminations and between different stromatolite morphologies. We will conduct statistical analyses on the model predictions and lab observations with the objective of evaluating the predictivity of these geochemical trends on the laminae growth patterns on Rocknest stromatolites. We will then extend the results of this case study to evaluate a dataset of high-resolution images of globally distributed stromatolites ranging in age from early Proterozoic to present.