9706237 Frost The purpose of the project is to determine the extent to which juvenile, mantle-derived magmas are added to the continental crust during production of anorogenic granites. This study will focus on the reduced rapakivi-type granites. Two models for their origin will be tested: (1) Production by melting of evolved continental crust and (2) production by partial melting of differentiated tholeiitic magmas emplaced at or near the base of the crust. The field area is the Sherman batholith in the Mule Creek block of the Laramide Mountains, Wyoming. This research combines field work, petrography geochemistry, Nd, Sr and Pb isotopic analyses, and determination of intensive parameters.