VOLUME XXI 1 



NUMBER 4 



THE 



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 



WALLACE W. ATWOOD 

 Physiography 



WILLIAM H. EMMONS 



Economic Geology 



ROLLIN T. CHAMBERLIN 

 Dynamic Geology 



ASSOCIATE EDITORS 



SIR ARCHIBALD GEIKIE, Great Britain 

 ♦HEINRICH ROSENBUSCH, Germany 

 *THEODOR N. TSCHERNYSCHEW, Russia 



CHARLES BARROIS, France 



ALBRECHT PENCK, Germany 



HANS REUSCH, Norway 



GERARD DeGEER, Sweden 



ORVILLE A. DERBY, Brazil 



T. W. EDGEWORTH DAVID, Australia 



BAILEY WILLIS, Argentine Republic 



*Deceased. 



GROVE K. GILBERT, Washington, D.C, 

 CHARLES D. WALCOTT, Smithsonian Institution 

 HENRY S. WILLIAMS, Cornell University 

 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 



MAY-JUNE 1914 



THE STRENGTH OF THE EARTH'S CRUST. IV. HETEROGENEITY AND RIGIDITY 

 OF THE CRUST AS MEASURED BY DEPARTURES FROM ISOSTASY 



Joseph Barrell 289 



DIASTROPHISM AND THE FORMATIVE PROCESSES. VII. PERIODICITY OF PALE- 

 OZOIC OROGENIC MOVEMENTS - - - - ■ - ROLLIN T. CHAMBERLIN 315 



ON THE RELATIONS OF THE GREAT MARLBOROUGH CONGLOMERATE TO THE 

 UNDERLYING FORMATIONS IN THE MIDDLE CLARENCE VALLEY, NEW 

 ZEALAND ------------ C. A. Cotton 346 



THE OSTEOLOGY OF SOME AMERICAN PERMIAN VERTEBRATES S. W. Williston 364 



STUDIES FOR STUDENTS: A CLASSIFICATION OF COMMON SEDIMENTS AND 

 SOME CRITERIA FOR IDENTIFICATION OF THE VARIOUS CLASSES 



Arthur C. Trowbridge 420 



PETROLOGICAL ABSTRACTS AND REVIEWS - - - 437 



REVIEWS --------- - - - 440 



THE UNIVERSITY OF CHICAGO 



CHICAGO, ILLINOIS, U.S.A. 



PRESS 



Agents 



THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 



WILLIAM WESLEY & SON, London 



KARL W, HIERSEMANN, Leipzig 



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



