VOLUME XXI 1 1 



THE 



SUPPLEMENT TO NUMBER 8 



Journal of Geology 



A Semi-Quarterly 



Edited By 



THOMAS C. CHAMBERLIN AND ROLLIN D. SALISBURY 

 With the Active Collaboration of 





SAMUEL W. WILLISTON 



Vertebrate Paleontology 

 STUART WELLER 



Invertebrate Paleontology 



ALBERT JOHANNSEN 



Petrology 

 ROLLIN T, CHAMBERLIN 

 Dynamic 



ASSOCIATE EDITORS 



SIR ARCHIBALD GEIKIE, Great Britain 



CHARLES BARROIS, France 



ALBRECHT PENCK, Germany 



HANS REUSCH, Norway 



GERARD DeGEER, Sweden 



ORVILLE A. DERBY, Brazil 



T. W. EDGEWORTH DAVID, Australia 



BAILEY WILLIS, Argentina 



GROVE K. GILBERT, Washington. D.C. 



CHARLES D. WALCOTT, Smithsonian Institution 



ARTHUR L. DAY, 



HENRY S. WILLIAMS, Cornell Universll 

 JOSEPH P.IDDINGS, Washington, D.C. 

 JOHN C. BRANNER, Leland Stanford Junior University 

 RICHARD A. F. PENROSE, Jr., Philadelphia, Pa. 

 WILLIAM B. CLARK, Johns Hopkins University 

 WILLIAM H. HOBBS, University of Michigan 

 FRANK D. ADAMS, McGill University 

 CHARLES K. LEITH, University of Wisconsin 

 WALLACE W. ATWOOD, Harvard University 

 WILLIAM H. EMMONS, University of Minnesota 

 Carnegie Institution 



SUPPLEMENT 



NOVEMBER-DECEMBER 1915 



THE LATER STAGES OF THE EVOLUTION OF THE IGNEOUS ROCKS - - N. L. Bowen 

 Introduction ------------ ----2 



Differentiation ---------------3 



The Association of Diabase and Micropegmatite - - - - - - - -17 



The Importance of the Formation of Biotite - - - - - - - - -41 



The Crystallization of Basaltic Magma ----------46 



Field Evidences of the Control of Crystallization in Differentiation - - - 48 

 The Alkaline Rocks --------------55 



Is Basaltic Magma the Parental Magma of All Igneous Rocks? - - - - 66 



The Normal Line of Descent ------------74 



Summary and Conclusion .-- 89 



THE UNIVERSITY OF CHICAGO PRESS 



CHICAGO, ILLINOIS, U.S.A. 



Agents 



THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 



KARL W. HIERSEMANN, Leipzig 



THE kARUZEN-KABUSHIKI-KAISHA, Tokyo, Osaka, Kyoto 



