Soils and Geology of Wisconsin Field Trip, May 2008
Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University of Wisconsin - Green Bay
Friday May 23
Berlin Rhyolite
Redgranite
Lake Wisconsin Shoreline
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Just west of Coloma, Highway 21 crosses from the recessional moraine onto the Lake Wisconsin plain. |
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The views here are looking east toward the edge of the moraine. |
Ship Rock
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A prominent joint runs the length of the rock, prompting Professor Luczaj to wonder if siliceous fluids hadn't percolated along the joint and made the rock more resistant to erosion. |
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Possible grinding holes at the base of the rock. |
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Witches' Gulch
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I'll get you, my pretty, and your little dog, too. The witch's profile appears at left center. |
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Devil's Lake State Park
Saturday May 24
East Bluff
Southeast Moraine Dam
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Devils Lake is dammed by a moraine at both ends. This is the moraine at the southeast end. |
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Devil's Doorway
Potholes Trail
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The Potholes Trail offers a view of enigmatic potholes carved by running water, but there is no stream here now. Meltwater from glacial ice atop the bluffs probably carved them. |
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The Potholes Trail is about the steepest trail at Devil's Lake. |
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Transverse ripples with longitudinal grooves |
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Making tracks for the van. |
Outside the Moraine Dam
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The moraine dam fills the bedrock valley about halfway to the top. This viewpoint would have been under ice at the time. |
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Being a soil scientist means never having to wonder what's beneath the surface. |
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Prairie vegetation, check. Lake silt for parent material, check. Mollisol. |
Parfrey's Glen
Devil's Lake
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Views from the south end looking at the northern moraine dam
Below, left: the east bluffs. Below, right: the east bluffs and southeast moraine dam. |
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Skillet Creek
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Baraboo quartzite at Skillet Creek. Excellent cross-bedding is visible here. |
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Slickensides on a small fault. |
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View of the Syncline from the North
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Road construction forced a detour that resulted in a serendipitous view across the syncline from the narrow North Range. |
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Abelman's Gorge
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Abelman's Gorge at Rock Springs is one of the best known geologic localities in the world. Once an abandoned quarry with iffy legal accessibility, it is now a state natural area. |
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A guitarist provided musical accompaniment. Rock music? |
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Wild Columbine |
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Above: Most of the good crystals have been mined out, but a few are visible in cavities |
Below: Quartzite breccia |
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Van Hise Rock
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A shear couple. Demonstrating how the foliation formed. |
Glacial Lake Baraboo
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The dark soils left of the road are histosols, the much lighter soils to the right are mollisols. |
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Going out to investigate the histosols. |
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And back to camp. |
Sunday May 25
Lower Narrows
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The Lower Narrows are where the Baraboo River exits the Baraboo Range. |
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A large rhyolite boulder is typical of the rocks beneath the quartzite. |
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Close-up of the rhyolite. |
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North end of the narrows, looking east. |
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Foliation in the rhyolite. |
Baraboo Interval Rhyolite
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Road relocation has left outcrops on Highway 33 no longer accessible, but a few miles west of the Lower Narrows is an accessible location. |
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Looking north over glacial lake plain. |
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Small outcrop of rhyolite. |
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It really does seem to have been that kind of campaign. A tourist attraction in Wisconsin Dells. |
Roche a Cri
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Roche a Cri is one of the most dramatic of the castellated mounds in central Wisconsin. |
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Graffiti of all ages is carved into the rock, ranging from prehistoric to recent. |
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You can climb the north end of the rock. |
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It's a very long climb. |
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But the view is the reward. |
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Despite the castellated mounds, there's no getting around the fact that central Wisconsin is flat. |
Rib Mountain
Eau Claire Dells
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Eau Claire Dells |
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Briefing on the geology |
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I have a photo of these potholes over 30 years old, and the difference in that time is close to zero. |
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How did graffiti from 1925 survive in a stream capable of polishing outcrops and creating potholes? Or was most of the carving done during glacial melt runoff? |
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Checking out the soil |
Tigerton Dells
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Below: Coarse granite of the Wolf River Batholith. |
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A pegmatite dike in the granite, with feldspar margins and a quartz center. |
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Created 29 August 2008 , Last Update 15 January 2020