VOLUME XXII 



NUMBER 6 



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 



SEPTEMBER-OCTOBER 1914 



THE STRENGTH OF THE EARTH'S CRUST. V. THE DEPTH OF MASSES PRO- 

 DUCING GRAVITY ANOMALIES AND DEFLECTION RESIDUALS {Continued) 



Joseph Barrell 



NOTES ON THE GEOLOGY OF THE SUN RIVER DISTRICT, MONTANA 



Sidney Powers and Hervey W. Shimer 



CORRELATION AND STRUCTURE OF THE PRE-CAMBRIAN FORMATIONS OF THE 

 GWINN IRON-BEARING DISTRICT OF MICHIGAN - - - R. C. Allen 



EVIDENCE OF THE MIDDLE-UPPER HURONIAN UNCONFORMITY IN THE 

 QUARTZITE HILLS AT LITTLE LAKE, MICHIGAN 



R. C. Allen and L. P. Barrett 



537 

 556 

 560 



574 



PHYSIOGRAPHIC RELATIONS OF SERPENTINE, WITH SPECIAL REFERENCE TO 



THE SERPENTINE STOCK OF STATEN ISLAND, N.Y. - - - W. O. Ceosby 582 



THE MODE OF FORMATION OF CERTAIN ""NiilSSES IN THE HIGHLANDS OF 



NEW JERSEY. I - - - - ^^ *• - - - Clarence N. Fenner 594 



THE MISSISSIPPIAN ROCKS OF NORTHEASTERN OKLAHOMA - - L. C. Snider 613 



PETROLOGICAL ABSTRACTS AND REVIEWS ----.----- 625 



REVIEWS ---------------- . 630 



THE UNIVERSITY OF CHICAGO 



CHICAGO, ILLINOIS, U.S.A. 



PRESS 



Agents 



THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 



KARL W. HIERSEMANN, Leipzig 



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



