MICROBIALITE MYSTERY: CHARACTERIZING DEVELOPMENT OF MICROBIALITES IN THE JURASSIC STRATA OF WYOMING

Microbialites have long been a diagnostic of paleoenvironmental conditions, and subsequent events throughout the Earth’s History. These organosedimentary structures are formed by microbial communities that mediate carbonate precipitation and detrital sediment suspension. These structures provide an in-depth insight of the environment that these microbial communities inhabited. One such period is that of the Middle Jurassic, in which North America was undergoing great transgressive-regressive cycles in the Sundance Sea. Along the Sundance Sea’s coastline, near what is now North-Western Wyoming, there are exposed microbialite horizons in the Gypsum Springs Formation due to uplifting during the Laramide Orogeny. The microbialites from this location may provide details of how the Sundance Sea might have changed over time but also what organisms lived in this region.

It is known that the internal architecture and structure of microbialites (i.e., stromatolite and thrombolite) may correlate to the depositional environments and climates in which they form. CT (Computed Tomography) provides a non-intrusive method to examine the 3D internal architecture and structure of lithified microbialites. This research aims to quantify 1) identification of microbialite internal structure and impacted fossils, 2) image traits in relation to density and composition, and 3) image quality of CT scan type (CT and Micro-CT). The CT method may be a more efficient way of identifying microbialite structure with non-intrusive techniques. Using CT or other X-ray technologies may help to better understand how microbialites of the Middle Jurassic not only formed in particular climates, but also illustrates how their structure may have changed from different events in the environment. This in turn provides a gradient that details the characteristics microbialites encompass to determine habitability of other organisms found inside the lithified structure but also the surrounding strata.