Vol. 13, No. 7, pp. 253-310, 3 figures in text, plates 15-16 May 31, 1922 



UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGICAL SCIENCES 



GENESIS OF THE ORES OF THE COBALT 

 DISTRICT, ONTARIO, CANADA 



BY 



ALFKED R. WHITMAN 



CONTENTS 



PAGE 



Introduction 254 



Review of ideas current in 1915 254 



Formations 254 



Structures 255 



Cobalt-silver veins 256 



Descriptive geology 257 



Pre-Cobalt surface 257 



The diabase sill r 260 



Structures 262 



Folds..., 262 



Faults 262 



Joints.: 266 



Cobalt silver veins 267 



Vein contents... 267 



Vein structures 268 



Space relations 269 



Paragenesis 270 



The genesis of the ores 271 



Diastrophism 271 



Major structural axes 271 



Injection of the diabase 273 



Minor structures 276 



Summary 278 



Current theories of vein genesis at Cobalt 279 



Descending solutions 279 



Ascending solutions 280 



General role of diffusion in vein genesis 288 



Mode of genesis of veins at Cobalt by diffusion 295 



Inception of diffusion : 295 



Migration 297 



Deposition 299 



Subsequent molecular rearrangement 302 



Conclusion 303 



Bibliography of the Cobalt district 306 



