Building materials as geologic samples

Thursdays for TeachersSeptember 24, 2009

The earth’s recycling system

Rocks related to other rocksRelated by processesThere is a cyclicity of earth processesProduct of our dynamic planet

magma

molten rock

igneous rock

Form from cooling and crystallization of magma (molten rock)

Liquid -> solidAtoms, ions, ionic complexesWith cooling, movement slowsAligned, orderedForm minerals

Igneous rocks (as well as other rock types) can be uplifted and exposed at the earth’s surface

Subject to atmosphere, hydrosphere, biosphere

Break down - weatheringSolid rock -> small particles & dissolved

material

magma

molten rock

igneous rock

uplift &weathering

cooling & crystallization

Dissolution of the mineral calcite

magma

molten rock

igneous rock

uplift &weathering

cooling & crystallization

sediment

Transported by water, wind, ice, gravityDeposited in different environmentsWeight of overlying sediment compresses

sediments belowCompaction of grains, expulsion of waterVoids filled with minerals (cement)Forms sedimentary rocks

magma

molten rock

igneous rock

uplift &weathering

cooling & crystallization

sedimentsedimentary

rock

transportation,deposition, &cementation

Continued burial, pressure & temperature rise

Chemical reactions occur (minerals out of stability fields)

Create new minerals and texturesMetamorphism (change)

magma

molten rock

igneous rock

uplift &weathering

cooling & crystallization

sedimentsedimentary

rock

transportation,deposition, &cementation

metamorphic rock

increased T & Pmetamorphism

igneousmetamorphic

magma

molten rock

igneous rock

uplift &weathering

cooling & crystallization

sedimentsedimentary

rock

transportation,deposition, &cementation

metamorphic rock

increased T & Pmetamorphism

melting

Can you think of any modifications we should make to the rock cycle to make it more realistic?

i.e. do all metamorphic rocks melt?do all sedimentary rocks become

metamorphic rocks?How can the rock cycle link to the water

cycle or the tectonic cycle?

magma

molten rock

igneous rock

uplift &weathering

cooling & crystallization

sedimentsedimentary

rock

transportation,deposition, &cementation

metamorphic rock

increased T & Pmetamorphism

melting

shortcuts

Look for different rock types in the museum

Think about how you could use your school or nearby buildings