CHAPTER VI. 
THE KEWEENAWAN ROCKS OF THE SOUTH SHORE OF 
LAKE SUPERIOR. 
InTRoDUCcTORY.—Rocks of the South Shore east of Keweenaw Bay.—Spread of the Keweenawan rocks 
on the South Shore.—The North Wisconsin synclinal.—Keweenaw Point selected as a typical 
region. 
SECTION I. KEWEENAW PoINT.—Sources of information.—Dimensions and position of Keweenaw 
Point.—Topography of the Point.—Connection between the topography and the rock structure. 
—Thickness of the rocks on Keweenaw Point.—Section of Keweenaw Point from the mouth of 
Eagle River to the Eastern Sandstone.—Rocks of Keweenaw Point east of the Eagle River 
section.—The Lake Shore Trap.—The Outer Conglomerate.—Rocks of the median valley.—The 
Bohemian Range.—Summarized section of the eastern part of Keweenaw Point.—Changes in 
the geology of Keweenaw Point southwest of Eagle River.—Section across Keweenaw Point 
in the vicinity of Portage Lake described in detail.—Rocks of Keweenaw Point between Portage 
Lake and Gratiot River.—Stannard’s Rock. 
SECTION II. THE REGION BETWEEN PoRTAGE LAKE AND ONTONAGON RIvER.—Continuance of the 
Portage Lake conditions through this district.—Differences between the Portage Lake and the 
Ontonagon sections.—The Nonesuch shale belt in the Ontonagon region.—The sandstones of 
the Upper Division in this district.—Thickness of Keweenawan rocks on the Ontonagon. 
Srction III. Tur SoutH RancE.—Position and extent of the South Range.—Its rocks are often over- 
laid by the newer sandstone.—Silver Mountain.—Exposures on the Ontonagon River; on the west 
branch of the Ontonagon.—Relation of the South Range rocks to those of the Keweenaw Point 
Range. 
SECTION IV. THE REGION BETWEEN THE ONTONAGON RIVER AND NUMAKAGON LAKE OF WISCONSIN.— 
Peculiar interest of this region.—Sources of information with regard to its geology.—Course and 
surface spread of the formation between the Ontonagon and the Montreal.—The Porcupine 
Mountains.—Porphyry of the Porcupine Mountains.—Its continuations east and west.—Other 
belts of the Porcupine Mountains.—Their east and west continuations.—The Montreal River 
section.—The Potato River section.—The rocks west of Bad River.—The sandstones of the Upper 
Division in the Bad River country. 
SECTION V. NORTHWESTERN WISCONSIN AND THE ADJOINING PART OF MINNESOTA.—Sources of infor- 
mation with regard to the geology of this region.—The Keweenawan rocks of this region lie in two 
parallel ranges, between which is a synclinal trough.—The southern belt; Numakagon Lake to 
the Saint Croix.—Important bearing of the exposures of the Saint Croix Valley on the question 
of the age of the Keweenaw Series.—Continuity between the Saint Croix rocks and those of 
Keweenaw Point.—Thickness of the Keweenawan rocks in this region.—Snake and Kettle River 
districts of Minnesota.—District of the Upper Saint Croix.—Douglas County Copper Range. 
—The peculiar phenomena of the contact in the Douglas County region between the Keweenawan 
rocks and the Western Sandstone. 
From the Sault westward to Marquette the formations of the country 
skirting the south shore of Lake Superior are flat-lying limestones and sand- 
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