Sorting it all out

Sorting

• Two main factors affect how materials in the earth are sorted:– Density– Particle size

Sorting - Density

• Under normal circumstances, more dense materials will end up on bottom, and less dense materials will end up on top.

Sorting - Density

• Sorting according to density can be seen in the earth’s layers

Sorting - Density

• Some salad dressings sort according to density.

Sorting – Particle size

• Even in items that sort according to density, particle size will affect the overall sorting because smaller particles might sift down through the gaps in bigger particles.

Sorting – Particle size

• If there is a disturbance (Like on the seashore, in a stream, or anywhere there is moving water),particle size is the main factor that determine how things will sort out.

Sorting – Particle size

• In a river, bigger, heavier rocks will sort out sooner, even though they may be slightly less dense, because the current can’t carry them as well.

Sorting – Particle size

• In slower moving parts of the river, smaller particles like sand and silt will settle out.

Sorting – Particle size

• How would you expect rocks to settle out on the beach?

Sorting – Particle size

How might the waves be different at these two beaches?

Sorting – Density and size

• Sorting according to density and particle size can also be seen in road cuts…

Sorting – Density and size

• …or mining

Sorting - Uses

• We use sorting in panning for gold

• Do you think this method of sorting is more affected by particle size or density?

Sorting - Uses

• Why do you put salad dressing on your salad and not salad on your salad dressing?

• Do you think this method of sorting is more affected by particle size or density?

Sorting - Uses

• Why do you put whipped cream on your pie instead of pie on your whipped cream?– Is this an example of

sorting by density or by size?

Sorting - Uses

• Why do you add salt to popcorn instead of popcorn to salt?– Is this an example of

sorting by density or by size?

Sorting - Uses

• If you throw a pencil into your backpack, where does it end up?– Is this an example of

sorting by density or by size?

Sorting – Inferring Earth’s history

• We can use our knowledge about how things are sorted to help us make inferences about events that occurred in Earth’s history.

• Changes to Utah

Lake Bonneville Sorting

Lake Bonneville Flood boulder size