ON THE SOUTH SHORE OF LAKE SUPERIOR. 427 
miles above its junction with the main or Middle Fork, is a ductile clay, that becomes 
hard and tough at a moderate heat in a common fire. On the “ Isle aux Barques,” 
the lime was so abundant that it had formed in amorphous concretions throughout 
the mass. A very few leaves and decayed sticks have been seen in these red, marly 
clays, with carbonaceous matter and lignite; but such organic contents are not of 
usual occurrence. 
Along the coast there are interstratified beds of sand and gravel of a local cha- 
racter. The section given by Mr. Randall, in the Report of 1847, and those I give 
below, illustrate this fact. In the interior, where the clay is visible in bold bluffs, 
along the water-courses, itis more uniform and less intercalated with coarse drift. 
It rests not only on the sedimentary unaltered rocks, but also on trap and meta- 
morphic and igneous rocks, as may be seen by consulting Sections 1, 2, 3, 4, W. 
The bold and curiously wrought face of the clay bluffs on the coast form scenes 
that attract the attention of the traveller, and are worthy the notice of the scenic 
painter. 
The following sections of the quaternary deposits on the south shore of Lake 
Superior and the adjacent islands, will give an idea of their relative position and 
thickness. The first was measured at the north end of Oak Island; the second at 
the bluffs one mile west of Pointe Ecorse, or Black Point; and the third is a section 
of three miles, from the coast to the mountains, four miles southwest of La Pointe. 
at oe 
a Tees The slope of this exposure 
is 380, ‘its foot protected from the waves in some degree by the boulders that fall from the bank. 5, Sand, thirty-five to forty feet. c. Red 
clay and youre twenty-five feet. d. Red and gray me twenty et *& Red clays and boulders, seventy- Pahhy oye ae total height above 
e hundred and seventy-three feet. e Superior. 
parr ped clay, twenty phir b. Gray sand, sixty feet. c. “Red homogeneous clay, fifty feet. Total height above the Lake, one hundred 
Pe dey feet. 
3. d. Coarse 
hauler arift, Lag top of which i ree! hundred =~ ee es, to sss bendred and ine feet ahqre the Lake. c. Red marly 
elay. ni 
iay, T 
This last section commences at the Lake near the mouth of a creek, which my 
half-breed voyageurs said was called by the Chippewas, Che-me-tau-gon-sibe; by 
the whites, Prairie River; and extends through the red clay to the top of the moun- 
Protoxide and peroxide of iron, soluble in hydrochloric acid 
efore fusion with carbonate of soda, 9-2 
“sé “6 es “cc afte ter 6“ a3 3 1°5 
: — 107 
Lime, te rT +6 before T3 rT “ 4-7 
‘“ 6 6 Ts after és 66 6é 0-7 
— 5-4 
Magnesia, “ “ “ before “ 66 6“ 2-6 
“ be 6 66 after “ a3 “ 0-7 
—-— «sW-8bB8 
Loss, ‘8 
100-0 
