ME. XXI NUMBER 3 
aa THE 
OURNAL or GEOLOGY 
A SEMI-QUARTERLY 
EDITED BY 
THOMAS C. CHAMBERLIN AND ROLLIN DsSALISBURY 
With the Active Collaboration of 
4 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. 
ee eCHT PENCK, Germany JOHN C. BRANNER, Leland Stanford Junior University 
pans 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 
APRIL-MAY 1913 
CHEMICAL COMPOSITION AS A CRITERION IN IDENTIFYING METAMORPHOSED 
“4 SEDIMENTS~ - - - - - - - - - - - EpsonS. BAstTIN 103 
OBSERVATIONS ON THE FELDSPARS - - - - - - AusTIN F. RoGERS 202 
“ROCK CLASSIFICATION ON THREE CO-ORDINATES - ALEXANDER N. WINCHELL 208 
THE OLD EROSION SURFACE IN IDAHO - - - - - - Jos—epH B. UMPLEBY 224 
NOTES ON THE ORIGIN OF CERTAIN PALEOZOIC SEDIMENTS, ILLUSTRATED 
’ BY THE CAMBRIAN AND ORDOVICIAN ROCKS OF CENTER COUNTY, 
£ PENNSYLVANIA - - - - - - - - - - Tuomas C. BROWN 232 
THE SECONDARY PRECIPITATION 0 GOLD IN ORE BODIES -Atpert D. BROKAW 251 
ORIGINAL STREAMS; AND THEIR ROLE IN GENERAL DESERT-LEVELING 
ay CHARLES R. KEYES 268 
“THE NATURE OF THE LATER DEFORMATIONS IN CERTAIN RANGES OF THE 
| ‘ GREAT BASIN - - - - - - - - - CHARLES LAURENCE BAKER 273 
EME NR Sa al ee ea eee 
a 
REVIEWS - < = = = x = a - = = is fs = = = - 284 
Bn chia 
funy? 
bi Pies INIVERSITY OF CHICAGO PRESS 
. tae CHICAGO, ILLINOIS, U.S.A. 
NH AGENTS 
THE CAMBRIDGE UNIVERSITY PRESS, Lonpon anp EDINBURGH 
WILLIAM WESLEY & SON, Lonpon 
\ TH. STAUFFER, LEIrzic 
» THE MARUZEN-KABUSHIKI-KAISHA, Toxyo, Osaka, Kyoto 
i 
