9317348 Bain PI will map, document, and collect unusual lacustrine stromatolites of Pennsylvanian age from a soon-to-be-reclaimed coal mine in Ohio. Petrologic, x-ray, microprobe and isotope analyses will also provide information about these Pennsylvanian-age non- marine water bodies and the growth of stromatolites in general. Collected information can be compared to other ancient and modern stromatolites, in particular in the Bahamas (San Salvador) lakes, where PI has conducted research.