Rocks of Michigan Investigative Problem
Adapted from NSTA Problem Based Learning in the Earth and Space Science Classroom K-12
Your Task: You will read the following story and explore the resources given in order explain how the types of rocks found in Michigan’s Keweenaw Peninsula today tell us about the geological history of the region. You will create a Google Slide presentation using the resources given below to present the information you have gathered and answer the problem.
The story:
Rebecca grew up in Santa Rosa, California, but one summer she visited her cousin Jason who lived on the Keweenaw Peninsula in the Upper Peninsula of Michigan. She was a little homesick. She was more than 2,000 miles from home, and much of the landscape was very different from what she was used to. But some of the rocks looked similar to the basalts around Santa Rosa. Where did all the basalt come from? This dark volcanic rock looked similar to the rocks on the West Coast, but on the West Coast they were associated with volcanic activity. But there weren’t any volcanoes in Michigan, were there?
There were also sedimentary rocks. Some were sandstones. Others were identified as conglomerates. They contained fist-sized pebbles. And the really interested thing was that these conglomerates were mixed in with the basalts. So there was a layer of volcanic rock, then a layer of conglomerates, then more volcanic rock-and this continued over and over again. How do you explain that? What is the story? What do the rocks tell us about what was going on in Michigan million of years ago?
During her investigation of the geology of the Keweenaw Peninsula, Rebecca looked up several types of information and went to a local museum to learn more about the natural history of the area. She used maps, a geological timescale, and some field guides to help her identify rocks she found as she explored the peninsula.
One of the people she met was an older man who had worked in the mines and was interested in rocks as a hobby. He showed her several “hand samples,” rocks she could hold and take a closer look at. He also told her that the layers of basalts and sedimentary rocks that were visible in the Keweenaw Peninsula continued under Lake Superior and resurfaced at Isle Royale and the western shore of Lake Superior. Geologists could”see” these buried layers, because the iron in the basalt affected Earth’s magnetic field.
Take a look at all the information Rebecca gathered while exploring the Keweenaw Peninsula and explain why these rocks are present in this way.
Websites with information on Michigan Geology
www.d.umn.edu/prc/lakesuperiorgeology/Volumes/ILSG_40_1994_pt2_houghton.cv.pdf.
http://custom.cengage.com/regional_geology.bak/data/Geo_Michigan_Watermarked.pdf.
www.educ.msu.edu/michiganrocks/PDFs/migeol1.pdf.
Watch the following video: https://www.pbs.org/video/nova-making-north-america-origins/
Maps
Michigan bedrock map: http://custom.cengage.com/regional_geology.bak/data/Geo_Michigan_Watermarked.pdf
This Dynamic Planet (interactive map website): http://nhb-arcims.si.edu/ThisDynamicPlanet/index.html
Geologic map of the Keweenaw Peninsula and adjacent area, Michigan (IMAP 2696): http://pubs.er.usgs.gov/publication/i2696
Pictures of the rocks found are on the following website:
Use figures 6.2, 6.3, and 6.4