%P 47-56 %L acta24757 %T Geochemistry of biotite and its significance as a guide to the origin of the granitoid rocks of El-Imra area, Eastern Desert, Egypt %O Bibliogr.: 56. p. ; ill. ; ĂśsszefoglalĂĄs angol nyelven %J Acta mineralogica-petrographica %X Biotites from the granitoid rocks of El-Imra, Eastern Desert, Egypt have been examined. The chemical data of 8 new analyzed biotites are presented. The behaviour of major and trace elements in the examined biotites are discussed according to different variation diagrams. The chemical composition of biotites has proved a reasonable guide to the magmatic origin of the host granitic rocks. %K KĹzettan, ĂsvĂĄnytan, FĂśldtan, GeokĂŠmia %D 1987 %I University of Szeged, Department of Mineralogy, Geochemistry and Petrology %C Szeged %V 29 %A Salem Abdel-Karim Ahmed %A Heikal Mohamed A. %A Kabesh Mahmoud Lofty %A Salem M. A.