Presentation by Dr. Jennifer McIntosh
Abstract: Low carbon emitting energy sources, such as natural gas from organic-rich coals and shales, are becoming increasingly important with climate change and rising energy demands worldwide. Approximately 20% of these natural gas (methane) resources are microbial in origin and were generated in the recent geologic past in deep (up to ~1 km) geologic formations, associated with influx of freshwater into saline aquifers during glacial periods. This leads to the intriguing hypothesis that microbial methane generation (methanogenesis) may be stimulated to produce new energy resources on human timescales. Yet, relatively little is known about the mechanisms and rates by which microbes naturally degrade organic carbon in the deep subsurface. This talk integrates hydrology, geochemistry, isotopes, and microbiology results from coal seams and black shales across the United States to better constrain the timing, mechanisms, and controls on microbial methane generation.