The Sedimentary Environment of Stromatolites in Hamelin Pool, Shark Bay, Western Australia
Paige E. Giusfredi, Pamela R. Reid, Erica C. Parke, and Gregor P. Eberli
School of Marine and Atmospheric Science at the University of Miami
Microbialites, including stromatolites, have been increasingly the focus of scientific study due to their relationship with hydrocarbon reservoirs. As the oldest evidence of life on earth, stromatolites have been present in the geologic record for the past 3.5 billion years. The diversity and density of these structures in Hamelin Pool, Shark Bay, Western Australia is unparalleled, existing as one of only two locations where modern marine stromatolites are found. The University of Miami has undertaken a comprehensive multi-year study to investigate this restricted marine system and the conditions that have allowed these structures to flourish. As part of this study, a vast collection of intertidal and subtidal stromatolites has been sampled. Understanding stromatolite-sediment interactions has begun to answer not only questions of formation, but also applicability of using modern stromatolites as analogues to the ancient. At over 1200 square kilometers, the sheer size of Hamelin Pool allows for exceptional diversity in microbial carbonates that dominate the 135km of shoreline. By quantifying grain size, mineralogy, and composition of the sediment, it is possible to assess if the stromatolites are preferentially selecting grain size during trapping and binding and additionally if the stromatolites are sources of sediment production. This unique study at Hamelin Pool provides insight into a complex restricted marine microbialite system that produces a variety of growth forms in the modern environment.
AAPG Search and Discovery Article #90182©2013 AAPG/SEG Student Expo, Houston, Texas, September 16-17, 2013