Sorting of Earth Materials

First, Some Questions:

1. If we have grains of sand of the same size but with different densities, how will they sort? (e.g. cat litter and gravel)

2. If we have particles of different sizes but the same density, how will they sort?

Answer 1When particles are the same size and the

different density (think of the density blocks we used) they will layer or sort according to density:

• Most dense on bottom, least dense on top.

Answer 2:

When particles are different sizes but the same density they will sort by size:

• Large particles on top, small on the bottom

Nature is more complicated. Let’s look at some real life examples:

* Beaches

* Rivers and Streams* Canyons, road cuts

How do the particles on a beach sort?

The bigger particles are farther up on the beach while the smaller grains of sand are closer to the water. Why do you think this happens?

Rivers and Streambeds

http://gregrob.ca/640x480/stream_bed.shtml

Remembering water is a factor we have to consider, how would particles sort in a stream?

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/fluvial_systems/geologic_work_of_streams.html

Canyons & Road cuts

Sorting of dry material

We can see examples of the sorting of Earth’s materials by looking at the Grand Canyon.

The earth’s surface is constantly changing. This occurs slowly. Grand Canyon !

http://geoscape.nrcan.gc.ca/nanaimo/images/photo_rock_layers_e.jpg

East Side of Flaming George