Biron Dam
Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University of Wisconsin - Green Bay
 |
NW 1/4 Sec 34, T23 N, R 6 E
Large outcrops of Archean granitic and tonalitic gneiss downriver from the dam just north of Biron. Access is from public parking at the north end of the dam. |
 |
 |
 |
|
 |
View of the dam |
 |
The main outcrop area |
 |
Left and below: Looking east from the outcrop area to the dam.
Below: looking along the contact between light granitic gneiss and darker tonalitic gneiss. |
 |
 |
 |
Close-up of foliated granitic gneiss |
 |
Close-up of foliated tonalite |
 |
Contact between granitic and tonalitic gneiss |
 |
Contact between granitic and tonalitic gneiss |
 |
Two ages of dikes in tonalite gneiss. |
 |
|
 |
|
 |
Banded tonalitic gneiss |
 |
Mafic dike cutting through granitic gneiss. |
 |
Differential weathering of granitic gneiss and tonalitic gneiss (darker and more weathered). |
 |
Differential weathering of granitic gneiss and tonalitic gneiss (darker and more weathered). |
 |
Chemical weathering along joint plane in tonalitic gneiss |
Return to Geology of Wisconsin Index
Return to Geologic Localities Index
Return to Professor Dutch's Home Page
Created 3 May 2005, Last Update 15 Jan 2020