VOLUME XX NUMBER 2 
THE 
JOURNAL OF icy 
A SEMI-QUARTERLY 
EDITED BY 
THOMAS C. CHAMBERLIN AND ROLLIN D. SALISBURY 
With the Active Collaboration of 
SAMUEL W. WILLISTON ALBERT JOHANNSEN : WILLIAM H. EMMONS 
Vertebrate Paleontology Petrology Economic Geology 
STUART WELLER WALLACE W. ATWOOD ROLLIN T. CHAMBERLIN 
Invertebrate Paleontology Physiography Dynamic Geology 
ASSOCIATE EDITORS 
SIR ARCHIBALD GEIKIE, Great Britain : GROVE K. GILBERT, Washington, D.C. 
HEINRICH ROSENBUSCH, Germany CHARLES D. WALCOTT, Smithsonian Institution 
THEODOR N, TSCHERNYSCHEW, Russia HENRY S. WILLIAMS, Cornell University 
CHARLES BARROIS, France JOSEPH P.IDDINGS, Washington, D.C. 
ALBRECHT PENCK, Germany JOHN C. BRANNER, Leland Stanford Junior University 
HANS REUSCH, Norway RICHARD A. F. PENROSE, Jr., Philadelphia, Pa. 
GERARD DEGEER, Sweden : WILLIAM B. CLARK, Johns Hopkins University 
ORVILLE A. DERBY, Brazil WILLIAM H. HOBBS, University of Michigan 
T. W. EDGEWORTH DAVID, Australia FRANK D. ADAMS, McGill University 
‘BAILEY WILLIS, Argentine Republic CHARLES K, LEITH, University of Wisconsin © 
FEBRUARY-MARGH, 1912 
CONTENTS 
AN EXPERIMENTAL CONTRIBUTION TO THE QUESTION OF THE DEPTH OF THE 
ZONE OF FLOW IN THE EARTH’S CRUST - - - 4- FRANK D. ADAMS — 97. 
ON THE LIMITING STRENGTH OF ROCKS UNDER CONDITIONS OF STRESS 
EXISTING IN THE EARTH’S INTERIOR. - - - - Louis Vessot Kine 119 
AN OLD EROSION SURFACE IN IDAHO: ITS AGE AND VALUE AS A DATUM PLANE 
JosrrpH B. UMPLEBY 139 
EUGEN HUSSAK STO es a pane ee hel Onin Sane nite, ome MITCUERT, A, LISBOA ATAS 
THE PETROGRAPHIC CHARACTER OF OHIO SANDS WITH RELATION TO THEIR 
ORIGIN” - Se - - - - 22D. Date CONDIT 152 
SOME OBSERVATIONS AND EXPERIMENTS ON JOINT PLANES - PEARL SHELDON 164 
REVIEWS Gs ra 7 oi i . = br = = = = - - - - = ~ I 8 4. 
Che University of Chicago ress 
CHICAGO, ILLINOIS 
AGENTS: | 
THE CAMBRIDGE UNIVERSITY PRESS, Lonpon anp EpINBURGH 
WILLIAM WESLEY & SON, Lonpon 
TH. STAUFFER, LeErrzic 
THE MARUZEN-KABUSHIKI-KAISHA, Toxyo, Osaxa, Kyoto 
