The constants were specific to these shales and may not apply elsewhere.Assumptions are  based on an organic matter density of 1.01 g/cc, a matrix density of 2.68 g/cc, and a ratio between weight percent of organic matter and organic carbon of 1.3. The study reported an average organic-carbon content  12.1 wt% (upper shale) and 11.5 wt%(lower shale), using data from more than 250 wells.