1 CONTENTS. 



Chapter IV. — The Lower Huronian — Continued. Page. 

 Section II. Acid and basic intrusives — Continued. 

 Giants Eange granite — Continued. 



Folding '. 358 



Metamorpliic action 359 



Interesting localities 359 



Relations to the Ely greenstone 359 



Relation to Soudan formation 359 



Metamorphism caused by granite 359 



Snowbank granite 361 



Distribution, exposures, and topography 361 



Petrographic characters : 361 



Relations to adjacent formations 363 



Relations to the Lower Huronian 363 



Relations to the Keweenawan gabbro 363 



Interesting localities 364 



Cacaquabic granite 364 



Distribution, exposures, and topography 365 



Petrographic character 365 



Relations to adjacent formations 368 



Relations to the Lower Huronian 368 



Relations to the gabbro 368 



Age 369 



Interesting localities 369 



Various acid dikes 369 



Distribution 369 



Petrographic characters 370 



Macroscopic characters 370 



Microscopic characters 370 



Relations to adjacent formations 370 



Basic and intermediate intrusives 371 



Interesting localities 373 



Chapter V. — The Upper Huronian (Animikie) 374 



Section I. Gunflint formation 374 



Distribution, exposures, and topography 375 



Distribution 375 



Exposures 376 



Topography 876 



Structure 376 



Petrographic characters 377 



Relation to other formations 387 



Relations to the Lower Huronian series — Ogishke conglomerate and Knife Lake slates. 388 



Relations to the Keweenawan (Duluth) gabbro 389 



Relations to basic dikes 390 



Thickness 390 



Section II. Rove slate 390 



Distribution, exposures, and topography 391 



Distribution 391 



Exposures 391 



Topography 391 



Structure 392 



Petrographic characters 392 



Microscopic characters 393 



Contact metamorphism 393 



