Abandoned Shore Lines of Luke Superior. — Taylor. 869 
in the Portage strait of that time and united Keweenaw Island 
to the mainland. The ease here is like that at Sturgeon Bay, 
Wisconsin; the canal is excavated almost wholly through 
littoral drift. It cuts through about 30 feet of sand and 
gravel near the north end, which shows plainly enough that 
the beach of the Nipissing episode was about at that level at 
that place. 
Again, near the outer end of Keweenaw point, we found this 
shore line strongly developed at Lac la Belle and along the 
shore eastward to the extreme point. Its altitude there is 
about 40 feet above lake Superior. Lac la Belle, like Au 
Train lake, was a hay cut oil' by the shore drift of the Nipis- 
sing beach. But it was not completely separated until a 
lower stage. We found this beach also on the north side of 
the point at Eagle Harbor as a sandy strip at about the same 
hight as at Lac la Belie. The second reach of the Nipissing 
beach, extending from Pequaming point to the north end of 
Portage lake canal, is also about 45 miles in length. 
Duluth. Farther west the coast was not seen at low levels 
except at Duluth and Superior. In that vicinity the Nipissing 
beach drops nearly to the present level of the lake. Minneso- 
ta point, which is about six miles long, and possibly Rices 
point also, are great spits which belong mainly to the shore 
line. They are not more than 10 or 15 feet above the present 
level of the lake and for this reason they must be attributed 
to present wave action, but the present shore does not show 
heavy littoral developments like these anywhere else. Be- 
sides, the observed gradual descent of the Nipissing beach 
toward the west would point to a probable lower level for it 
at Duluth. There is also another reason which agrees with 
this expectation. The horizon of the Nipissing beach, in the 
two stretches described above, shows such a gnat degree of 
modification by wave action as compared with contiguous 
higher ground that the line of demarkation could hardly 
be missed. The great spits near Duluth are like the Nipissing 
beach farther east. But the ground immediately above them, 
the broad terrace upon which Superior is built, is totally un- 
like that beach, for it is composed mainly of red (day. In one 
section, about five feet deep, line horizontal layers or lamina- 
tions were seen, which indicate that it is a deep, -till water 
