The Pennsylvania Supreme Court has agreed to address on appeal whether interpreting the term "mineral" in a deed reservation allows for the introduction of scientific and historic evidence about the Marcellus shale in light of the Dunham rule. (Butler v. Charles Powers Estate, Apr. 3, 2012). The argument: "The Powers heirs, in an argument with wider implications for gas leases in the state, claimed that since Marcellus gas is trapped in rock and doesn’t flow freely to the surface, as gas did from oil wells in the 1880s, it should be considered a mineral and part of the rights explicitly transferred in the deed, according to court records." (Bloomberg).