Evocative Question

How are the geologic principles for understanding the Earth’s history like a layer cake?

Uniformitarianism

The geologic processes that happen today (mountain building, volcanoes, rocks) happened the same way in the past AND change on the Earth is occurring slowly and constantly.

How is this like a cake? The Principle of Uniformitarianism is like a

layer cake because people basically make cakes the same way every time.

Superposition

In horizontal sedimentary rock layers, the oldest layer is at the bottom. Each higher layer is younger than the layers below it.

How is this like a layer cake? The Principle of Superposition is like a layer

cake because the bottom layer was put down first (oldest) and the top layer was placed last (youngest).

Original Horizontality

Sediment settles out of water in horizontal layers. Larger sediment settles first and smaller sediment settles later. Sedimentary rocks form in horizontal layers.

How is this like a layer cake? The Principle of Original Horizontality is like a

layer cake because the layers should be placed horizontally.

Catastrophism

Geologic Change occurs suddenly How is this like a layer cake?

The Principle of Catastrophism is like a layer cake because if you drop it, it’s gone wrong suddenly!

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More Simile Examples

Before you get ready to write your own similes, here are a few more examples that are not related to cake. The Principle of Superposition is like your

dirty clothes pile. The shirt you wore longest ago is on the bottom, and the shirt your wore most recently is on the top.

The Principle of Uniformitarianism is like riding a bike. You always ride a bike in the same way.

The principle of Original Horizontality is like a house. The floors in a house are laid out horizontally.