Driftless Area in Minnesota, — Grant. 379 
many outcrops of gabbro much decayed, and in places there is 
considerable residual soil. \'ery few fresh rock surfaces were 
seen. No large foreign boulders were noted, but there are a 
very few small boulders of slate and granite, usually under 
eight inches in diameter. Aside from these boulders no drift 
was noted. This lake is surrounded by gabbro hills, all decay- 
ing into soil. The shores of the lake in section 32, T. 64-6 W,, 
also show many outcrops of decaying rock. Between the last 
mentioned lake and the Kawishiwi river, in section 5, T. 63- 
6 W., the gabbro is commonly very much disintegrated and 
practically no foreign boulders were seen. On the south and 
west shores of this river in sections 4 and 5, T. 63-6 W., the 
.same rock decay is very marked and boulders of disintegration 
are forming. On lake Polly the gabbro. while showing some 
.<igns of decay, is not nearly as much decayed as in the localities 
to the north just mentioned, and near the southeast side of this 
lake the usvial glaciated and more or less drift-covered district 
is encountered. 
On the Kawishiwi river in sections 21, 16, 17. 8 and 7, T. 
63-6 W., especially in the last two sections, the rock is much 
disintegrated. Only a few small foreign boulders occur. One 
noticeable feature is the presence of a few bosses of smooth, 
fresh gabbro within a few yards of other bosses which are much 
decayed. These smooth bosses show no glacial striae. The 
same character of country as above described is seen about 
lake Alice, but on the portage northward from this lake to 
Thomas lake the gabbro is not particularly decayed and drift 
is present in considerable quantity. 
From the above descriptions it is evident that the area under 
<liscussion is in some respects markedly different from the sur- 
rounding country. These dififerences may be included under 
three heads: 
First: The absence, except for a very few, small, foreign 
boulders, of glacial deposits. These boulders might have been 
brought in by floating ice. The surrounding country shows 
abundant evidences of glacial drift, although in many localities 
the thickness of the drift is slight. But even in such places 
and on bare glaciated knobs foreign boulders are numerous 
and not infrequently of considerable size. 
Second: (jlacial striae are absent. Outside of this area 
