Geology of Ice Age National Scientific Reserve of Wisconsin
NPS Scientific Monograph No. 2
Drumlins have been by far the longest known and best
known streamline molded forms (Flint 1957:66). Charlesworth
(1957:389-403) lists 302 citations to the literature extant at the time,
and many other papers on drumlins have appeared since. To this day the
origin of drumlins remains conjectural, only in part because different
streamline molded forms are called drumlins. Alden (1918:253-256, Pl.
III) last mapped and described the drumlins of southeastern Wisconsin
where about 5000 drumlins are recognized (Fig. 38). Drumlins and
drumlinoidal ridges and flutings in the Campbellsport area (Figs. 1, 2,
4, 39) were included on Alden's geologic map, but not specifically
mentioned in the text. Neither were they among those mapped and
described in an earlier report (Alden 1905) which still provides us with
the bulk of our information on the drumlins of Wisconsin.
Fig. 38. Drumlins of southeastern Wisconsin. After Alden (1918) via
Prouty (1960, Fig. 7).
Alden (1918:253-255) wrote:
The writer prefers to restrict the name drumlin to
those drift hills which show clearly the molding effect of the advancing
ice. The typical drumlin of southeastern Wisconsin may be said to be a
hill of glacial drift which approximates the form of a segment of an
elongated ovid, of which the widest part of the basal outline and the
highest point of the crest are generally not more distant from the
stross end than one-third the length of the major axis, and whose major
axis is oriented parallel to the direction of the movement of the
glacier which formed it. From this type the forms vary on the one hand
to elongated narrow ridges, some of which attain lengths of 3 to 4
miles, and on the other hand to nearly equiaxial dome-shaped or
mammillary hills. Exceptional variations are double-tailed and double
and triple crested forms, and ridges with subordinate crests overlapping
in echelon. The longer forms were developed principally in the region of
axial movement of the glacier and in the tract west of the Niagara
escarpment, where there was good opportunity for the incorporation of
sticky aluminous clay derived from the Cincinnati shale [part of
Maquoketa, Fig. 3]. The presence of the adhesive clay doubtless
facilitated the building up of drumlins by the plastering-on process,
and the elongation of the forms may be some function of the more rapid
movement along the Winnebago-Rock River trough. There is a general
shortening of the forms progressively toward the limit of the advance,
where the rate of flow was retarded owing to the thinning and wide
radial spreading of the moving ice. The shortening of the forms on the
upland east of the Niagara escarpment may be due to the retarding effect
of this escarpment on the ice overriding it in addition to that
resulting from thinning and radial spreading.
. . .
With but few exceptions the partial sections of
drumlins seen by the writer exposed compact structureless clayey till
like that composing most of the rest of the ground-moraine deposit over
the limestone areas. In some places the till is semistratified, with
somewhat indefinite bands that curve conformably with the surface
contours and suggest that the hill has been built up by the addition of
more or less definite layers.
Layers of stratified sand and gravel or stoneless
silt are exposed in sections of few drumlins. These are in some cases
folded, and it is not clear that they have any definite relation to the
drumlin structure as such.
A fairly definite cleavage in the clayey matrix of
the till developed parallel to the curved surface suggests the effects
of pressure of the overriding ice but may in reality be the result of
successive additions of thin layers of adhesive clayey material. . . .
Evidence indicating the absence of rock cores from the drumlins has been
collected throughout the whole drumlin area.
. . .
Estimates based on pebbles collected from drift
composing drumlins show . . . that about 91 per cent of the coarser
material is of local derivation. If the analyses included also the finer
material comprising the matrix of the till the percentage of local
material present might be found to be even larger. This high percentage
of local material indicates that the drumlins are composed of drift
accumulated at or near the base of the ice and transported for
comparatively short distances.
. . .
The drumlins were formed . . . in those parts of the
area of the Green Bay' Glacier where the lines of movement were
radiating very notably as the ice spread to the curved margin of the
lobe. The lines of movement bounding any drumlin-forming segment of this
glacier from the north limit of the drumlins in the area of that segment
to the peripheral margin of the lobe show that the amount of this
spreading is very considerablemuch greater than that which took
place in similar segments of the glacier of equal initial width but
within whose area no, or few, drumlins were formed. This relation gives
rise to the suggestion that radiation was an important factor in drumlin
formation. . . .
On Alden's map (1918, Pl. III) distinction was made
between drumlins according to the description above and drumlinoidal
ridges and fluted forms of similar shape and dimensions. No list of
criteria distinguishing between the two were set up, although such forms
with bed rock cores seem automatically to be called drumlinoidal. Such
practice is generally, but not universally, followed today. Obviously by
surface inspection alone, it is not always possible to distinguish true
drumlins in Alden's sense from drumlinoidal ridges and fluted forms, and
I make no pretext of doing so. Stratification of till (non water-worked)
and drift (water-worked) in drumlins in Wisconsin seen by me is much
more complicated than Alden described, but details cannot be entered
The specific drumlins and drumlinoidal forms of the
Campbellsport area doubtless were specified in the Act because of their
proximity to the Northern Kettle Interlobate Moraine rather than because
of their uniqueness or unusual degree of development. The best drumlins
(including drumlinoidal forms) in the vicinity of Campbellsport are
centered 4 miles northwest of that town (Fig. 39). There the drumlins
are generally 60-120 ft high, rounded, irregular, to elliptical.
Elongation ratios commonly are less than 2:1. Some of the drumlinoidal
forms are believed to have bedrock cores. The more symmetrical and
elliptical drumlins clearly show deployment of the ice, but only minor
flutes on the irregular forms show it.
Fig. 39. Part of U.S. Geological Survey Topographic
QuadrangleCampbellsport, showing general areas of drumlins
recommended for the Reserve. Possible waysides are shown with black
dots. Scale 1 mile per inch.
The Campbellsport drumlins, although typical of many
in Wisconsin, are neither the highest, longest, largest, nor most
symmetrical. They are closest to the Northern Kettle Interlobate Moraine
and provide good views of such features from county roads not heavily
traveled. In the area of better drumlins and drumlinoidal forms shown in
Fig. 39 are some locations of possible roadside overlooks, not all of
which are needed to give the visitor a good view of the drumlins.
Typical views of the Campbellsport drumlins, from some of the
recommended overlooks, are recorded in Figs. 40-42.
Fig. 40. View eastward of the long-profile of the drumlin with an
elevation of 1123 ft, centered at the corners of secs. 9, 10, 15, and 16
(Fig. 39). The steeper stross (up ice) side shows clearly on the left.
Fig. 41. View southeastward of the cross-profile of the drumlin in the
north-central part of sec. 10. Camera position is on County Highway Y,
in the saddle in the SE1/4 SW1/4 sec. 3 (Fig. 39).
Fig. 42. View north-northwest of cross-profile of the drumlin in the
center of sec. 28 as seen from the possible overlook on the town road,
0.25 mile west of the southeast corner of that section (Fig. 39).
Inasmuch as most of these drumlins seem to be
composed of the pale yellow-brown sandy calcareous till typical of the
drumlins and ground moraine over a broad area of the northern part of
Green Bay Lobe, it is not likely that many would be destroyed if they
were not in public ownership. The till makes good farm land, a
relatively firm base for construction, but is only poorly suited for
construction aggregate. Con sequently, available funds should go mainly
toward acquisition of land associated with the Northern Kettle
Interlobate Moraine, Devils Lake Park, and the Bloomer Moraine. Two or
three of the proposed road sides shown in Fig. 39, for views of the
drumlins, seem sufficient to me to integrate these features into the
Larger, well-developed, rounded drumlins may be seen
readily from State Highway 23, County Highway AA, and connecting town
roads about 5 miles east of Fond du Lac (Figs. 4, 43). Elongated
drumlins, with ratios of 5-10:1, are well displayed in the area south of
Mayville and south and east of Horicon (Figs. 4, 44). Many drumlins
south of Juneau and southwest of Beaver Dam are even more elongated and
larger (Figs. 4, 45). Drumlins are less well developed in northern
Fig. 43. Part of U.S. Geological Survey Topographic QuadrangleFond
du Lac, showing drumlins.
Fig. 44. Part of U.S. Geological Survey Topographic
QuadrangleHoricon, showing drumlins. Scale 1 mile per inch.
Fig. 45. Part of U.S. Geological Survey Topographic
QuadrangleBeaver Dam, showing drumlins.
Fabric studies of the stones and finer particles in
the till in the drumlins in Wisconsin have not been attempted. Few
mineralogical and textural data are available. Obviously much subsurface
geological study is needed to describe the drumlins adequately and to
reconstruct their possible origin.
Last Updated: 1-Apr-2005