THE WISCONSIN AND MENOMONIE RIVERS. 455 
CANADA MICHIGAN MICHIGAN MICHIGAN | WISCONSIN 
SURVEY. SURVEY. SURVEY. SURVEY. SURVEY. 
Messrs, LoGAN AND| Dr. HouaaTon. S. W. Hicarns. Dr. Houcuton. C. WHITTLESEY. I. A. Lapuam. D. D. Owen. 
MuRRaY. | 
Section from Gros|From Lake Huron|From Mackinaw to|Bay de Noquet toHeads of Oconto Milwaukie to Madi-Falls St. Anthony 
Cap Range to along St. Mary’s| Grand Island. Chocolate River.| River to Little) son, Wisconsin. to Keokuk. 
Manitou Islands. River to Gros Sturgeon Bay. 
Cap Range. 
ae es E 
Syenite, granite, Igneous rocks ofI[gneous and trap- 
re Wisconsin River.| pose rocks of 
rocks. 
as i, i: 1. 
Igneous rocks, Gros Trappose and igne-\Igneous and trap-|Igneous rocks 
Cap range. ous rocks. Gros-| pose rocks be- 
$ Cap. neath Lake Su- 
perior 
Red and variegated t 
sandstone (Pots- 2. White and gray} Sis5sippi 
dam). Soft saccharoid) sandstone (F. 1), 
Madison, 
2. 
Altered sandstones 
‘7 
an Red and iegated 
rates (Potsdam).| sandstones (Pots- Red and variegated sandstone, with Wis- , 
dam). sandstones, base 3. breccia and red| consin, Light-coloured 
3. of Grand Island /Galciferous sand-| bands. sandstone, Mis- 
Trenton. 3. and Pictured] sock. ‘ sissippi and Wis- 
incinnati blue} Rocks. 3. Lower magnesian| consin (F. 1). 
limestones an 4. Siliceous lime-rock.| limestone (F, 2), 
3. 
Lower magnesia 
limestone, Mis- 
4. 
Utica slates. shales. ns Birdseye and 
Upper gray sand-| Trenton. 4. 4. 
5. 4. rock. Bluish-green lime-|Cincinnati 
Lorraine shales. |Utica slate. stone. 
eT  Galerea nine . 
5. limestone (F.3,a), sissippi ee bag 
4. Cincinnati blue Ripley Lake. cont — 
6. 5. Trenton and Birds-| limestone. DB. 2), em po zg 
Limestoneof Drum-/Medina sandstone.| eye. Cincinnati _— blue 5 pag 
mond and Mani- 6. limestone. Upper magnesian 
toulin Islands, - bl Intermediate lime- ener aaa — : 
disturbed by in-|Limestone of Mack-|Cincinnati ue} rocks. ng ime-/ g 
trusive quartz,) inaw and Drum-| limestone. rock, Fort Atkin- gruel anol 
and other igne-| mond Islands. T son. Paltent Antik oo “ 
a rae Mackinaw lime- 6 and mouth off 
Intermediate lime- k. g : A “Sait 
rocks. ae |Supposed red sand- Wisconsin River. 
stone. r 
i. . 
. Upper Magnesian 
Mackinaw, Hime : LOA, ey Se os 
stone. Waukeshaw _lime- lead-bearing 
mons. rock. Dubuque, 
Galena. 
8. 
Ait 6. 
gore: Devonian rocks. 
9. : 
Shaly sandstone. Coal-measures, 
Keokuk. 
Corniferous, Lake 
Michigan, Mil- 
kie. 
Mr. Logan does not give the Blue Limestone, but has what is regarded as its 
equivalent, the “Trenton Limestone” of New York. The early Michigan geolo- 
gists separated the Trenton from the Blue, probably as a provisional arrangement, 
based on lithological difference. | 
Let us now bring the comparison to bear on the arrangement of the rocks on the 
waters of Green Bay. Although I was unable at any point to get measurements 
for dip, it is evident that the rocks, as a system, plunge away from the great cen- 
tral uplift of igneous rocks, that is, to the east and south. Along the Neenah 
River, the dip is slight and irregular, the bedding of the rocks, although frequently 
well defined, is not traceable in long lines from point to point. 
The general plunge being easterly and southeasterly, we are satisfied, as we 
progress from the shore of Lake Michigan westward and northwestward, that the 
rocks that appear to our view are older than those on the Lake. But in the absence 
of calculations on the dip of these rocks, their thickness cannot be measured, or even 
estimated with an approach to accuracy. 
The limestone bluffs north and east of Tayhedah, overlooking Lake Winnebago 
from the southeast, appeared to me the highest rocks of the Fox River Valley, both 
