where [[S2]] is the amount of hydrocarbons generated through thermal cracking of nonvolatile organic matter in mg/g of rock<ref name=NL Oil and Gas Portal>[http://www.nlog.nl/en/activity/analyses.html NL Oil and Gas Portal]</ref> and [[Total organic carbon (TOC)|TOC]] is total organic carbon in %.
+
where [[S2]] is the amount of hydrocarbons generated through thermal [[cracking]] of nonvolatile organic matter in mg/g of rock<ref name=NL Oil and Gas Portal>[http://www.nlog.nl/en/activity/analyses.html NL Oil and Gas Portal]</ref> and [[Total organic carbon (TOC)|TOC]] is total organic carbon in %.