Public Education and Outreach
We also can find carbonaceous rocks that contain significant organic material in the form of Kerogen (with perhaps some bitumen). The prevailing thought regarding the formation of this material is algal blooms in lake. There is a summer (thick) layer and a thinner winter layer that dies and settles on the bottom of the lake. This created an organic rich sediment that eventually formed a source rock. The many layers of source rock that are formed indicated that this process might have been occurring for a few million years. Thus, there is a lot of organic material in oil shales. Unfortunately, the long time periods required for crude oil formation and high temperatures have not been obtained and so we have a source rock with very immature crude oil precursor. We can mine the oil shale, crush and retort (heat with steam) to extract the kerogen. This can then be upgraded or gasified to supply electricity. We have large quantities of oil shale in the US (large areas of the oil shale containing land, are owned by the US Navy (why?). World wide the 5 to 6 times the world resource of petroleum. But have you ever heard of it? Currently it is still cheaper to purchase crude oil than to produce oil from the treatment of oil shale kerogen. The locations in the US are out West mostly within the Green river formation of Utah/Wyoming.