VOLUME XIX 



NUMBER 3 



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 



WALTER 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 



GROVE K. GILBERT, National Survey, Washington, D.C. 



CHARLES D. WALCOTT, Smithsonian Institution 



HENRY S. WILLIAMS, Cornell University 



JOSEPH P.IDDINGS, Washington, D.C. 



JOHN C. BRANNER, Stanford University 



RALPH A. F. PENROSE, 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 



APRIL-MAY, 191 1 



CONTENTS 



CERTAIN PHASES OF GLACIAL EROSION 



Thomas C. Chamberlin and Roixin T. Chamberlin 193 



VALLEY FILLING BY INTERMITTENT STREAMS - - - A. E. Parkins 217 



ORIGINAL ICE STRUCTURES PRESERVED TN UNCONSOLIDATED SANDS. 



Charles P. Berkey and Jesse E. Hyde 223 



RESTORATION OF SEYMOURIA BAYLORENSIS BROILI, AN AMERICAN COTY- 



LOSAUR --------------------- S. W. Williston 232 



GEOLOGIC AND PETROGRAPHIC NOTES ON THE REGION ABOUT CAICARA, 



VENEZUELA --------------- ----- T. A. Bendrat 238 



THE AGE OF THE TY'PE EXPOSURES OF THE LAFAYETTE FORMATION 



Edward W. Berry 249 



THE RIPPLES OF THE BEDFORD AND BEREA FORMATIONS OF CENTRAL AND 

 SOUTHERN OHIO, WITH NOTES ON THE PALEOGEOGRAPHY OF THAT EPOCH 



Jesse E. Hyde 257 



A POSSIBLE LIMITING EFFECT OF GROUND-WATER UPON EOLIAN EROSION 



Joseph E. Pogtje 270 



RECENTLY DISCOVERED HOT SPRINGS IN ARKANSAS - A. H. Purdue 272 



REVIEWS ----------------------------- 276 



PETROLOGICAL ABSTRACTS AND REVIEWS ■ - - 283 



€])z 2Jutfcerg(ti? of Chicago ptz$$ 



CHICAGO, ILLINOIS 



Agents: 



CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 



WILLIAM WESLEY & SON. London 



TH. STAUFFER, Leipzig 



