Learning target: I can work with a team to use clues about a region's rocks, climate and plate history to predict which natural resources it has, and explain each prediction with the process that forms the resource.
Directions
Work in home groups of four. Step 1 (expert round, 12 minutes): each member takes one region's three cards (Region 1: cards 1-3; Region 2: cards 4-6; Region 3: cards 7-9; Region 4: cards 10-12), reads them, and meets with the students from other groups who hold the same region to agree on what the region has and why. Step 2 (home round, 18 minutes): return to your home group, teach your region in two minutes, and complete the group prediction table together. Step 3 (challenge, 8 minutes): trade tables with a neighboring group and challenge one prediction with evidence from the cards. Step 4 (individual, 12 minutes): answer Part C alone. The four regions are invented for this activity, but every clue is the kind geologists really use.
You will need: Twelve cards per group, cut from the card sheet, One prediction table per group, Pencils, Timer
Twelve evidence cards (four invented regions, three cards each)
1 Card 1: Cinder Range, the rocksA chain of steep volcanoes, two of them active, runs through the region. Between the volcanoes, old granite is exposed, laced with quartz veins that carry green and blue copper stains. Soils on the slopes are thin and stony. Hot springs bubble up along a line of cracks in the rock.
2 Card 2: Cinder Range, climate and waterRain and snow total about 1,200 mm a year. Streams run all year, fed by snowmelt. Shallow aquifers in the valley gravel refill every spring; a well drilled in 1995 shows the same water level today as when it was drilled. Water from one spring comes out at 96 °C.
3 Card 3: Cinder Range, plates and historyAn oceanic plate sinks beneath the region today, 150 km to the west, and has done so for about 40 million years. Earthquakes are frequent. Magma sits 5 to 8 km below the volcanoes. The region has never been under the sea in the last 100 million years.
4 Card 4: Saltmarsh Flats, the rocksFlat land underlain by thick layers of limestone and shale. The limestone is full of fossil clams and corals. Below 2 km, drillers pass through a dense shale that bends into a broad arch, then a porous sandstone, then a dark shale that smells of oil. No volcanic rock anywhere.
5 Card 5: Saltmarsh Flats, climate and waterRain totals about 200 mm a year; it is a semi-desert. The only aquifer is 300 m down in old sandstone; its water, when tested, last fell as rain roughly 12,000 years ago. The water level in the region's wells has dropped 15 m in the last 30 years.
6 Card 6: Saltmarsh Flats, plates and historyThe region sits in the middle of a plate, 1,500 km from the nearest boundary. About 150 million years ago it lay under a warm, shallow sea for tens of millions of years. Later it was buried under new sediment and gently folded. No volcano has erupted here in 300 million years.
7 Card 7: Riverbend Lowlands, the rocksA wide valley floor of silt and clay dropped by a large river's floods, layer on layer. The dark topsoil is 1 to 2 m thick and rich in decayed plant matter. Below the silt is 50 m of sand and gravel, then hard, ancient bedrock with no fossils. No ore minerals have ever been found.
8 Card 8: Riverbend Lowlands, climate and waterRain totals about 1,100 mm a year, spread through the year. The river floods most springs. Wells in the sand and gravel refill within weeks after pumping, and water levels have been steady for 60 years. Forests of fast-growing trees cover the hills on either side of the valley.
9 Card 9: Riverbend Lowlands, plates and historyThe region is deep inside a continent, far from any plate boundary. The bedrock is about 2 billion years old and has been worn flat; it was once part of a mountain range that eroded away long before the valley formed. The region has not been under the sea for more than 400 million years.
10 Card 10: Old Shield Plateau, the rocksA high, flat plateau of ancient granite and gneiss, worn smooth. No layered sedimentary rock, no fossils, no volcanic rock younger than a billion years. Soils are a few centimeters thick or absent. A few old quartz veins carry traces of copper, too thin to mine.
11 Card 11: Old Shield Plateau, climate and waterRain totals about 150 mm a year. There are no permanent streams. The only aquifer is in cracks in the granite 200 m down; its water last fell as rain about 20,000 years ago, when the climate was wetter. The one town's wells have dropped 25 m in 40 years.
12 Card 12: Old Shield Plateau, plates and historyThe region is in the stable interior of a plate; the last subduction zone here shut down more than a billion years ago, and the mountains it built eroded away. There has been no magma near the surface since then, and no sea for at least 500 million years.