Global Survey and Distribution of Pennsylvanian and Mississippian Microbial Mounds


  • Clarice Kiser


Microbial mounds, including Waulsortian and Waulsortian-like mounds, are lithified structures composed of carbonate compounds and ancient microbes that aided in the production of those compounds. They commonly developed in shallow sea environments of the Pennsylvanian (323 to 299 Ma) and Mississippian (359 to 323 Ma) era strata due to the photosynthetic tendencies of cyanobacteria and its environmental symbionts that require marine environments (i.e.: phylloid algae). The lithification of these microbes can give insight to biosignatures left by this process and can therefore inform our understanding of microbial mounds on Earth and, potentially, on other planets.
This study serves to build a global database of microbial mounds from these geologic eras, which span 60 million years. This database will include geographic data from scientific studies of microbial mound structures from the last 31 years (1990-2021). We sift through these studies to find the specific locality of when and where the specimens are found and then pinpoint the location on Google Earth. With these locations pinpointed, we can construct paleogeographic maps and compare the ecology, location, and sedimentary character of each mound. This is done in order to find similarities in conditions on ancient shallow marine slopes and determine the fundamental controls on mound formation. Understanding the conditions necessary for microbial mound growth is a first step toward predicting where mounds may have developed elsewhere in the Solar System.






Earth Sciences