-Landforms are the result of the combination of constructive and destructive processes.
8.3.1.2.1 Explain how landforms result from the processes of crustal deformation, volcanic eruptions, weathering, erosion and deposition of sediment.
8.3.1.2.2 Explain the role of weathering, erosion and glacial activity in shaping Minnesota's current landscape.
Learning Targets:
I can find Bruce Vento Nature Sanctuary on a map.
I can describe how the Mississippi River, weather, erosion and glacial activity shaped the current landscape of St. Paul and the Bruce Vento Nature Sanctuary.
Learning Activities:
Introduce guiding questions and/or learning targets by posting visually. Ask students to respond with initial understandings either in writing or verbally.
Read the following quote: The Mississippi is well worth reading about. It is not a commonplace river, but on the contrary is in all ways remarkable. Considering the Missouri its main branch, it is the longest river in the world -- four thousand three hundred miles. It seems safe to say that it is also the crookedest river in the world, since in one part of its journey it uses up one thousand three hundred miles to cover the same ground that the crow would fly over in six hundred and seventy-five. It discharges three times as much water as the St. Lawrence, twenty-five times as much as the Rhine, and three hundred and thirty-eight times as much as the Thames. No other river has so vast a drainage-basin: it draws its water supply ... from Delaware, on the Atlantic seaboard, and from all the country between that and Idaho on the Pacific slope -- a spread of forty-five degrees of longitude. The Mississippi receives and carries to the Gulf water from fifty-four subordinate rivers that are navigable by steamboats, and from some hundreds that are navigable by flats and keels. The area of its drainage-basin is as great as the combined areas of England, Wales, Scotland, Ireland, France, Spain, Portugal, Germany, Austria, Italy, and Turkey; and almost all this wide region is fertile; the Mississippi valley, proper, is exceptionally so." -- from Life on the Mississippi, written by Mark Twain in 1863
Show students the historic picture of St. Anthony Falls in St. Paul and a current picture of the falls in Minneapolis (below). Explain that 12,000 years ago the natural waterfall was in St. Paul just south of Bruce Vento Nature Sanctuary. Use google earth or the map provided to point out the specific location. Ask students: How or why did the St. Anthony waterfall move several miles.
Read Have students text code ‘A Waterfall on the Move’ and ‘Waterfalls 101’ by underlining important information, placing a star by information they already knew, and questions marks by items they would like to know more about. Ask each student to share one item that was text coded.
Watch the waterfall animation showing how waterfalls retreat. Ask one or two students to describe the process verbally while watching the clip. Another option is for students to describe the process in pairs. http://www.classzone.com/books/earth_science/terc/content/visualizations/es1305/es1305page01.cfm?chapter_no=visualization
Watch ‘1. Introduction’ and 4. Geology’ of Bruce Vento Nature Sanctuary Tour DVD.
Introduce fieldwork by describing the Sandcastle or Imniza Ska ‘White Cliffs’ in Dakota created by erosion over 450 million years ago at Bruce Vento Nature Sanctuary. Use the pictures to again point out the following layers. From the bottom up…
Sandstone formed 455-458 million years ago by water washing over sandy beaches, is 135 feet deep and has some of the most pure sandstone (100% silica) in the world.
Shale formed 454-455 million years ago, few feet deep and is mud mixed with sand
limestone 453-454 million years ago, 25 ft. deep ocean covered the area fossils
Explain to students that your class will be creating a model river in the sand at the sanctuary. They will be expected to participate in the creation of the model and answer question on a lab report.
9. Describe the expectations: see ‘Fieldwork Resources’ for more information and suggestions).
Assessment for Learning:
Text coding share out
Waterfall explanation
Resources:
Google map of historic and current location of St. Anthony Falls
Remember! It is very important that students to not climb on, dig or in any way modify the walls of the sandcastle. Only use sand that is in the existing pit. Thank you for ensuring the maintenance of this important natural structure.
