Principles of Relative Dating




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The links below are animations illustrating the principles of relative dating (determining the sequence of events) and to images of real examples on which to try out the principles. To return to this page, click your Back button.

Click on each of the five small images below to bring up an animation about the seas moving in and out. Click and drag sideways to move the seas in and out, and drag up and down to see what's beneath the water.

Deposition of a layer of sand as the sea moves in. This shows how a beach sand can cover a huge area.

Deposition of  layers of sand and mud as the sea moves in . This shows how different types of sediment can be deposited at the same time and how one type can be deposited over another type.

Deposition of layers of sand, mud, and limestone as the sea moves in.

Deposition of layers of sand and mud as the sea moves out.

Deposition of a layer of sand as the sea moves out and is followed by sand dunes.
Click on each of the three small images below to see an animation about relative dating.  Each  animation will replay automatically when it finishes.
layers_deposited_thumbnail.gif (62501 bytes) Deposition of layers, followed by erosion
pc_removal_start.jpg (69629 bytes) Imaginary removal of one rock unit at a time, showing how the rock units are layers that go through the hills.
layers_ final_mesa_thumbnail.gif (108663 bytes) Erosion of a sequence of layers, forming a mesa and then buttes.
Click on each of the small pictures below to see a photograph illustrating principles of relative dating.
canyonlands_dhp.jpg (169025 bytes) Canyonlands - Youngest layer is on top, oldest on the bottom.
hance_dike.jpg (139940 bytes) Hance Rapids, Grand Canyon - Younger features crosscut older rocks.
Death Valley - Younger rock units can contain pieces of older rocks.
raplee_distance.jpg (173339 bytes) Raplee Monocline, Utah - Rocks generally are deposited in nearly horizontal layers.  If the layers are no longer so, then they must have been effected by some event, such as folding or tilting.
grand_canyon_overview.jpg (239854 bytes) Eastern Grand Canyon - An angular unconformity is where older rocks were tilted, eroded, and overlain by younger rock layers.
If you want, click on the Overviews button below and view one of the overviews in order to try out the principles on Painted Canyon. Or, visit the page below.
Key Age Relationships of Painted Canyon:  Images of key places, each of which reveals clues about the sequence of geologic events that formed Painted Canyon.

There is no link back to this page and probably no need to return here, but if you want to revisit this page you can either click the Back button as many times as it takes to get here or close the program and start over.