Precambrian

Mountain ranges created during the Cenozoic Era include the

What continent existed 1.8 billion years ago that now forms the core of modern North America?

The most common Precambrian fossils are

The gradual development of new organisms from preexisting organisms is called

The Pliocene Epoch began about 5.3 Ma, or

What evidence supports the hypothesis that Earth is 4.6 billion years?

Earth had no ozone layer in its upper atmosphere, so the planet was scoured by _____________.

What is the name of the Precambrian shield in North America?

The first period of the Mesozoic Era was called the

A hypothesize that early Earth was hotter than Earth today, is helped proved by what evidence.

On a geologic column, the oldest rocks

What was the original composition of Earth's atmosphere?

Scientists have most accurately determined the absolute ages of rock layers by

Which of the following does NOT show evidence that Earth is about 4.6 billion years old?

Scattered landmasses on Earth merged into a supercontinent during

__________ are the building blocks of proteins.

Scientists think the most important requirement for life is _____________.

Scientists created the first geologic column by determining the rel ages of sedimentary rock in

stable mineral that commonly occurs in granite

If the Cretaceous Period began about 146 Ma, this means it began

Why do not Archean and Proterozoic rocks have iron oxides?

Many new life-forms in the first period of the Paleozoic Era was aided by the development of

What supercontinent is shown in the figure?

deepest, most stable part of a continent

According to the impact hypothesis, dinosaurs became extinct when

__________ are rocks that have alternating bands of fine-grained quartz and iron oxides.

The Devonian Period is also known as the

The division of geologic time that makes up about 88% of Earth’s history is called

A scientist assume about a rock layer that matches a similar layer in a geologic column?

The end of the Permian Period was marked by

What did organisms of Earth's first 4 billion years have in common?

Nearly half the Earth’s valuable mineral deposits are found in rocks from

A geologic period is usually named for

What were the type of life-forms that existed before the Proterozoic?

mat or mound composed of billions of cyanobacteria

tiny, threadlike photosynthetic organisms

What are areas called that contain cores of Archean and Proterozoic rock?

The Cenozoic Era is known as the

The oldest rocks on Earth are __________.

Which areas of N A were most affected by the formation of the Canadian Shield?

What substance in Earth's atmosphere protects organisms from UV radiation?

How were asteroids and meteorites a heat source for Precambrian Earth?

The mass extinction at the end of the Permian Period led to