Fossils and Geological Time Flashcard

Front

What evidence led to the discovery of the giant asteroid impact that extinguished the dinosaurs?

Back

The discovery of large chunks of the asteroid in Mexico.

Front

What do scientists study to learn about climate changes near a glacier?

Back

Ice cores.

Front

Why do we only see one side of the Moon?

Back

Because one rotation and one revolution take the same amount of time.

Front

What are the primary elements that compose all of the outer planets?

Back

Hydrogen and helium.

Front

What can you determine if you know a planet's orbital period?

Back

Its distance from the Sun.

Front

What is a fossil?

Back

A preserved remains or traces of ancient organisms.

Front

What is the geological time scale?

Back

A system of chronological dating that relates geological strata to time.

Front

What is radiometric dating?

Back

A method used to date materials by comparing the abundance of a radioactive isotope to its decay products.

Front

What are index fossils?

Back

Fossils of organisms that were widespread but only existed for a short period, used to date rock layers.

Front

What is the significance of iridium in geology?

Back

Iridium is rare on Earth but abundant in asteroids, indicating an asteroid impact.