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TerraPrinter Classroom · Worksheet · Ages 11–16
Mountain building: when plates collide
Name Class Date
Where two plates carrying continents push into each other, neither sinks easily. The rock is squeezed, folded and pushed up into mountains. Use the models of Mount Everest and the Valley and Ridge in Pennsylvania to compare a young mountain range with an old one.
Open a link in a web browser to see the model in 3D, or use the printed model from your teacher.
The Himalaya are still forming. The Indian plate is pushing into the Eurasian plate. In which direction is India moving?
Find the summit of Everest on the model. How many main ridges run out from the summit? Describe its shape.
The rock near the top of Everest is limestone with fossils of sea creatures. How could rock from the sea floor end up at the top of the world?
Everest is 8,849 m high and is still being pushed up by a few millimetres a year. If it rose 4 mm a year, how much higher would it get in 10,000 years?
Look at the Pennsylvania model. Describe the pattern of the ridges and valleys.
The ridges are hard sandstone. The valleys are softer shale and limestone. Explain why the hard rock is left standing as ridges.
Sketch rock layers before and after being squeezed from both sides. Label: upfold (anticline), downfold (syncline), and arrows for the push.
The Appalachians formed about 300 million years ago and were once much higher. Why are they so much lower than the Himalaya now?
TerraPrinter Classroom, CC BY 4.0: free to copy and adapt with credit.
TerraPrinter Classroom · For the teacher
Answer key: Mountain building: when plates collide
Learning goals
Describe what happens where two continents collide.
Explain how rock layers are folded and pushed up into mountains.
Compare young, high mountains with old, worn-down ones, and explain the difference with erosion.
Answers
The Himalaya are still forming. The Indian plate is pushing into the Eurasian plate. In which direction is India moving?North (roughly north-north-east), about 4–5 cm a year. The collision began about 50 million years ago.
Find the summit of Everest on the model. How many main ridges run out from the summit? Describe its shape.Three main ridges (north-east, south-east and west), with three faces between them, so the summit is shaped like a three-sided pyramid.
The rock near the top of Everest is limestone with fossils of sea creatures. How could rock from the sea floor end up at the top of the world?It formed from layers of shells and mud on the floor of an ocean that lay between India and Asia. When the plates collided, the layers were squeezed, folded and pushed up into the mountains.
Everest is 8,849 m high and is still being pushed up by a few millimetres a year. If it rose 4 mm a year, how much higher would it get in 10,000 years?40,000 mm = 40 m. (In reality erosion wears some of that away again.)
Look at the Pennsylvania model. Describe the pattern of the ridges and valleys.Long, narrow ridges lined up side by side, running from south-west to north-east, with long valleys between. In places a ridge bends round in a hairpin turn where a fold dips into the ground. Rivers cross the ridges through narrow gaps.
The ridges are hard sandstone. The valleys are softer shale and limestone. Explain why the hard rock is left standing as ridges.Rain, rivers and frost wear soft rock away faster than hard rock. Over millions of years the soft layers are worn down into valleys and the hard layers are left standing up as ridges.
Sketch rock layers before and after being squeezed from both sides. Label: upfold (anticline), downfold (syncline), and arrows for the push.Before: flat, level layers. After: the layers bend into waves; the arches are anticlines and the troughs are synclines. Arrows point inward from each side.
The Appalachians formed about 300 million years ago and were once much higher. Why are they so much lower than the Himalaya now?They have been worn down by rain, rivers, ice and frost for hundreds of millions of years, and no collision is pushing them up any more. The Himalaya are young and still being pushed up.
Before the lesson
Print the models at 150 mm wide, 0.2 mm layers, 10–15% infill, no supports. Everest is at true scale (1×): it needs no help to stand tall, and makes a tall print, so allow an overnight print. The Pennsylvania ridges are only a few hundred metres high, so they are drawn 3× taller to show up. Measurements on the sheet assume the 150 mm size. Students' measured answers will vary a little with how they measure. Discussion questions and a hands-on activity for this topic: terraprinter.com/classroom/#mountain-building
