Willis P. Doering Donald E. Lee 1974 <p>In a magmatic environment, barium usually substitutes for potassium in the crystallizing silicates, and the two increase together in rocks late in the differentiation sequence. Results of this study show the opposite trend in an equivalent of a large part (63-76 percent SiO₂) of the classic differentiation sequence that resulted mainly from assimilation of chemically distinct host rocks. The barium content of the hybrid granitoid rock appears to be controlled mainly by the barium contents of the various sedimentary rock types assimilated.</p> application/pdf en U.S. Geological Survey Barium in hybrid granitoid rocks of the southern Snake Range, Nevada article