Geologic Time

Front

What is the law of superposition?

Back

The law of superposition states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest layers are at the top.

Front

Which layer is the youngest according to the law of superposition?

Back

The youngest layer is the one at the top of the sequence.

Front

What is the correct order of rock layers from oldest to youngest?

Back

C, B, A, D, E.

Front

How old was the Silurian Period?

Back

The Silurian Period was about 420 million years ago.

Front

What is the Mesozoic Era?

Back

The Mesozoic Era is a geological era that lasted from about 252 to 66 million years ago, known for the dominance of dinosaurs.

Front

How many years ago did the Mesozoic Era begin?

Back

The Mesozoic Era began about 245 million years ago.

Front

What does the geologic time scale represent?

Back

The geologic time scale represents the timeline of Earth's history, divided into eons, eras, periods, and epochs.

Front

What is a fossil?

Back

A fossil is the preserved remains or traces of ancient organisms, often found in sedimentary rock.

Front

What is the significance of index fossils?

Back

Index fossils are used to identify and date the layers of rock in which they are found, indicating a specific time period.

Front

What is radiometric dating?

Back

Radiometric dating is a method used to determine the age of rocks and fossils by measuring the decay of radioactive isotopes.