Wala 
POUKNAL OF GEOLOGY 
A Semi-Quarterly Magazine of Geology and 
Related Sciences 
EDITORS 
T. C. CHAMBERLIN, zz General Charge 
R. D. SALISBURY 
Geographic Geology 
J. P. IDDINGS 
Petrology 
STUART WELLER 
Paleontologic Geology 
R. AV ok. RENROSE, Jr: 
Economic Geology 
CR. VAN HISE 
Pre-Cambrian Geology 
W. H. HOLMES 
Anthropic Geology 
ASSOCIATE EDITorsS 
SIR ARCHIBALD GEIKIE 
Great Britain 
H. ROSENBUSCH 
Germany 
CHARLES BARROIS 
France 
ALBRECHT PENCK 
Austria 
HANS REUSCH 
Norway 
GERARD DE GEER 
Sweden 
GEORGE M. DAWSON 
Canada 
O. A. DERBY 
Brazil 
GILBERT 
Washington, D. C. 
WILLIAMS 
Yale University 
JOSEPH LE CONTE 
University of California 
(Co ID WKOMIE{COYAE AL 
U.S. Geological Survey 
J. C. BRANNER 
Stanford Untversity 
iC RUSSHVE 
University of Michigan 
Ga IK 
libs. 
WILLIAM B. CLARK, Johus Hopkins University 
VOERUNE x 
CHICAGO 
Ss, 
as 
By lnstituys 
2 > 50422) 
Metionai Musev 7 
Che Anibversity of Chicago Press L 
1902 
