Waupaca
Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University
of Wisconsin - Green Bay


Several outcrops of a variety of Precambrian rocks occur in Waupaca. They
include:
- Fine-grained pink granite on Granite Street
- Dark, fine-grained intrusive rocks at Rasmussen Park
- Metamorphic rocks along the Waupaca river
- Fine-grained probable metavolcanic rocks at a flooded quarry (now a park).
Granite Street
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Fine-grained pink granite outcrops along Granite Street. If
the name "Granite Street" seems a bit obvious, bear in mind that
a lot of people in Wisconsin refer to Baraboo Quartzite as
"granite." |
Rasmussen Park
The panorama below shows the park. Both fine-grained dark intrusive rocks and
pink granite occur. A large erratic of Waupaca rapakivi adamellite is visible at
the left top of the hill. There are undisputed granitic rocks a few hundred
meters to the west on Granite Street, metamorphic rocks a couple of hundred
meters to the east along the river, and this appears to be a contaminated border
facies. It is very similar to the petrology along the northern margin of the
Wolf River Batholith at High Falls Dam
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A pinkish, granitic phase |
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Dark, fine-grained rock cut by a small granitic dike |
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A somewhat coarser, dark intrusive phase, very similar to
the dark border rocks at High Falls Dam. |
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Above and at left are three general views of the outcrops |
Waupaca Adamellite
Waupaca River
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The outcrops are located in the river and woods northeast of
the municipal garage on Water Street. |
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There is a small park on the river bank. The outcrops begin just north of the
parking lot. Views of the outcrops are below. |
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This is a view looking north from the bridge. The outcrops
begin about at the distance of the truck. |
Outcrops on the River
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The outcrops in the river and on the riverbank are pinkish
on weathered surfaces. They generally show a weak subvertical N-S
foliation |
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Outcrops in the Woods
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Above and left: general appearance of the outcrops in the woods. They are
best seen when the leaves are gone and even then, getting at them involves clawing
through brambles. |
Intrusive Rocks
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Outcrops in the woods away from the river show generally
uniform texture with numerous small dikes and veins and are probably
intrusive. The contact probably runs roughly parallel to the river and
just west of it. |
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This outcrop shows a contact and a very obvious xenolith. |
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Uniform fine-grained rocks with dikes |
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Uniform fine-grained rocks with dikes |
Foliated Rocks
Outcrops in the woods closest to the river have a crudely
gneissic appearance.
Quarry Park
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A view of the park. It's reached most easily by walking
along the railroad tracks. |
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A trail leads around the quarry. |
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Much of the rock here is pinkish, fine-grained, and uniform. |
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On weathered surfaces the rock sometimes has a banded or
foliated appearance. Thus, it is not intrusive, but more likely
metavolcanic. These rocks are similar to the outcrops in the Waupaca
River. |
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Created 3 May 2002, Last Update
11 Jan 2020