Oil shale geology

A pick axe sitting on a wider, protruding rock. Various sized rock prudences are in the photo; most are a little wider than the pick handle.
Outcrop of Ordovician kukersite oil shale, northern Estonia
Lower Jurassic oil shale near Holzmaden, Germany

Oil shale geology is a branch of geologic sciences which studies the formation and composition of oil shales–fine-grained sedimentary rocks containing significant amounts of kerogen, and belonging to the group of sapropel fuels.[1] Oil shale formation takes place in a number of depositional settings and has considerable compositional variation. Oil shales can be classified by their composition (carbonate minerals such as calcite or detrital minerals such as quartz and clays) or by their depositional environment (large lakes, shallow marine, and lagoon/small lake settings). Much of the organic matter in oil shales is of algal origin, but may also include remains of vascular land plants. Three major type of organic matter (macerals) in oil shale are telalginite, lamalginite, and bituminite.[2] Some oil shale deposits also contain metals which include vanadium, zinc, copper, and uranium.[1][3]

Most oil shale deposits were formed during Middle Cambrian, Early and Middle Ordovician, Late Devonian, Late Jurassic, and Paleogene times through burial by sedimentary loading on top of the algal swamp deposits, resulting in conversion of the organic matter to kerogen by diagenetic processes.[1][4] The largest deposits are found in the remains of large lakes such as the deposits of the Green River Formation of Wyoming and Utah, USA. Oil-shale deposits formed in the shallow seas of continental shelves generally are much thinner than large lake basin deposits.[5]

  1. ^ a b c Ots, Arvo (2007-02-12). "Estonian oil shale properties and utilization in power plants" (PDF). Energetika. 53 (2). Lithuanian Academy of Sciences Publishers: 8–18. Archived from the original (PDF) on 2013-06-05. Retrieved 2011-05-06.
  2. ^ Cite error: The named reference hutton was invoked but never defined (see the help page).
  3. ^ Dyni, John R. (2006). "Geology and resources of some world oil-shale deposits. Scientific Investigations Report 2005–5294" (PDF). United States Department of the Interior, United States Geological Survey. Retrieved 2007-07-09.
  4. ^ Cite error: The named reference es832 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference sme was invoked but never defined (see the help page).