GEOS 1004 Lecture Notes - Lecture 11: Titusville, Pennsylvania, La Brea Tar Pits, Tethys Ocean
Document Summary
Organic- living organisms form mineral shells/skeletons from ions in solution; from un-decayed plant material that was buried before it could oxidize. 1) i. e. coquina (from shells), limestone, chalk, flint and chert (form of sio2 - silica from diatom skeletons), coal. Sedimentary basins bury the remains of living organisms as well as debris eroded from rock. Preserving organic remains requires quiet basins as organic material is: i. ii. Fossil fuels form in sedimentary basins with the right burial conditions i. ii. Fossil fuel deposits are hosted by sedimentary rocks. Too much heat and pressure (enough to cause metamorphism, for example) convert the organics into materials unusable for fuel. Coal forms mostly from accumulated plant debris that does not decay at earth"s surface. Burial heating drives out non-carbon material to make coal, which is at least 70% carbon. Material typically collects in swamps, bogs, and marshes (fresh or brackish water) lacking abundant free oxygen.
