Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN><SPAN>Percent shale was computed from facies-distribution maps (Budnik and Smith, 1982) of the Lower and Upper Pennsylvanian-age rocks, respectively. The main assumption we made here was that the Granite Wash included only shale and coarser grained clastics but no bedded carbonates. This is, of course, not strictly true, but Dutton (1982a) did present several figures that imply relatively minor amounts of carbonate interbedded with the Granite Wash. Therefore, this map can more correctly be called "percent shale and carbonate." </SPAN></SPAN></P><P><SPAN /></P></DIV></DIV></DIV>