326 CONTENTS. 



Chapter III.— The Felch Mountain Range— Continued. Page. 



Section "VII.— The Groveland formation 415 



Distribution, exposures, and topography 415 



Petrographical characters -•-• 417 



Section VIII.— The mica schists and quartzltes of the Upper Huronian series 423 



Petrographical characters 425 



Section IX.— The intrusives 426 



Chapter IV.— The Michigamme Moitntain and Fence Kivbr areas 427 



Section I.— The Archean 428 



Section II. — The Sturgeon formation 430 



Section III.— The Randville dolomite 431 



Distribution and exposures 431 



Folding and thickness 432 



Petrographical characters 434 



Section IV.— The Mansfield formation 437 



Distribution, exposures, and topography 438 



Folding and thickness 438 



Petrographical characters 439 



Section V. — The Hemlock formation 440 



Distribution, exposures, and topography 440 



Folding and thickness 441 



Petrographical characters 442 



Section VI. — The Groveland formation 446 



Distribution, exposures, and topography 446 



Folding and thickness 448 



Petrographical characters 448 



Chapter V.— The northeastern area and the relations between the Lower Mar- 

 quette AND the Lower Menominee series 451 



Chapter VI.— The Sturgeon River tongue, by William Shirley Baylby 458 



Description and boundary of area 458 



Literature 459 



Relations between the sedimentary rocks and the granite-schist complex 461 



The Basement Complex 463 



The gneissoid granites 463 



The amphibole-schists 465 



Origin of the amphibole-schists 466 



The biotite-schists 467 



The Intrusive rocks 469 



Comparison of the Sturgeon River and the Marquette crystalline series 470 



The Algonkian trough 471 



Relations between the conglomerate and the dolomite series 472 



Relations between the dolomites and conglomerates and the overlying sandstones 473 



The conglomerate formation 473 



Important exposures 474 



Petrographical descriptions 477 



The dolomite formation 479 



Important exposures 480 



Petrographical description '. 481 



Slates and sandstones on the Sturgeon River 481 



The igneous rocks 482 



The intrusive greenstones 482 



Petrographical description --. 482 



The banded greenstones 485 



Petrographical description 486 



