Soils and Geology of Wisconsin Field Trip, May 2008

Steven Dutch, Natural and Applied Sciences, University of Wisconsin - Green Bay
First-time Visitors: Please visit Site Map and Disclaimer. Use "Back" to return here.

Friday May 23

Berlin Rhyolite


	On the east side of Berlin, three quarries adjoin the town cemetery. The quarries extract Precambrian rhyolite but two of them have Cambrian basal conglomerate preserved. This is the central quarry.
	Left: Relic of quarry operations. Below: Faint flow textures in the rhyolite.


	Above: View of the north wall with rhyolite at the waterline and Cambrian conglomerate in the upper half of the exposure. Left and below: closeups of the contact.

	Standing on the contact
	Flow banding is conspicuous on this weathered surface.

Redgranite

	A deep flooded quarry in Redgranite.
	Glacial striations and chatter marks on Post-Penokean granite.
	Chatter marks
	A conspicuous example of plumose fracture.
	The spine in the center of the picture is a mafic dike that extends across the quarry.
	Left: Flow banding adjacent to the dike contact. Below: More views of the dike contact.

Lake Wisconsin Shoreline

	Just west of Coloma, Highway 21 crosses from the recessional moraine onto the Lake Wisconsin plain.
	The views here are looking east toward the edge of the moraine.

Ship Rock

Witches' Gulch

Devil's Lake State Park

Saturday May 24

East Bluff

Southeast Moraine Dam

Devil's Doorway

Potholes Trail

	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.






	The Potholes Trail is about the steepest trail at Devil's Lake.




	Making tracks for the van.

Outside the Moraine Dam

Parfrey's Glen

Devil's Lake

Skillet Creek

	Baraboo quartzite at Skillet Creek. Excellent cross-bedding is visible here.
	Slickensides on a small fault.

View of the Syncline from the North

	Road construction forced a detour that resulted in a serendipitous view across the syncline from the narrow North Range.

Abelman's Gorge

	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.
	A guitarist provided musical accompaniment. Rock music?




	Wild Columbine


Above: Most of the good crystals have been mined out, but a few are visible in cavities	Below: Quartzite breccia

Van Hise Rock

Glacial Lake Baraboo

	The dark soils left of the road are histosols, the much lighter soils to the right are mollisols.
	Going out to investigate the histosols.
	And back to camp.

Sunday May 25

Lower Narrows

Baraboo Interval Rhyolite

	Road relocation has left outcrops on Highway 33 no longer accessible, but a few miles west of the Lower Narrows is an accessible location.
	Looking north over glacial lake plain.
	Small outcrop of rhyolite.
	It really does seem to have been that kind of campaign. A tourist attraction in Wisconsin Dells.

Roche a Cri

	Roche a Cri is one of the most dramatic of the castellated mounds in central Wisconsin.

Rib Mountain

	Mosinee Hill in the foreground, with Rib Mountain in the distance.
	Lunch time.


	♪ Here come the men in black... ♫ A number of picnickers were slightly freaked by seeing us pull up with a string of dark vans.
	View west from the summit.
	The quartzite monadnock at Rib Mountain was once believed to be the highest point in Wisconsin.

	How spheroidal weathering occurs in highly uniform quartzite is a mystery.
	Lichens
	The quartzite is so uniform that bedding is all but impossible to see, but this ripple-marked surface furnishes a good indication.

Eau Claire Dells

	Eau Claire Dells
	Briefing on the geology





	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?