. "stable"@en . "+*SSRO"@en . . . "Organic-rich sediment and sedimentary rock"@en . "Organic-rich sediment and sedimentary rock"@en . . "Organic-rich sediment and sedimentary rock - In the Rock Classification Scheme, these are defined as those sediments and sedimentary rocks where the organic content is sufficiently high to have a noticeable effect on the lithology. A definition based on a greater than 50% volumetric abundance of organic matter is not possible because historically the definitions of sediments and sedimentary rocks rich in organic-matter have been based on their quality as fossil fuels. British Geological Survey Research Report RR/99/03, section 6 and fig. 10."@en . . .