Fossils and Rock Layers Flashcard

Front

What are fossils?

Back

Fossils are the preserved remains or traces of plants and animals that lived in the past.

Front

What do rock layers tell us about Earth's history?

Back

Rock layers can show the order in which different types of plants and animals lived, indicating changes in the environment over time.

Front

What does it mean if a rock layer is older than another?

Back

An older rock layer was formed before a younger layer, meaning it contains fossils from an earlier time period.

Front

How can we tell if an area has changed over time?

Back

By studying the types of fossils found in different rock layers, we can see how the environment has changed, such as from dry to wet.

Front

What is the significance of finding plant fossils like ferns and cacti in the same rock layer?

Back

It suggests that the environment changed from very dry (cacti) to more damp (ferns) over time.

Front

What does an earthquake do to rock layers?

Back

An earthquake can break and shift rock layers, indicating that the earthquake occurred after some layers were formed.

Front

What can we infer if clams are found below tree fossils in rock layers?

Back

It suggests that the area where these fossils were found changed over time, possibly from a seashore to a forest.

Front

What is the Law of Superposition?

Back

The Law of Superposition states that in undisturbed rock layers, the oldest layers are at the bottom and the youngest are at the top.

Front

Why are some fossils found together in the same rock layer?

Back

Fossils found together often indicate that the organisms lived in the same environment at the same time.

Front

What does it mean if a rock layer is 'unconformable'?

Back

An unconformable layer indicates a gap in the geological record, where erosion or other processes removed layers before new ones were deposited.