Earth History

During the early Paleozoic era what was the vast southern continent

A large meteorite may have contributed to the mass extinction That ended__________________Era.

Began with 20 g of a radioactive parent isotope. How many grams be present after 2 half-lives?

In what type of rocks are most fossils found?

The time it takes for 50% of the nuclei in a radioactive sample to decay is called ____.

The dating process that places geologic events in proper sequence is

Which span of geologic time spans covers about 88 percent of Earth’s history?

In the early Paleozoic, life was restricted to the ____.

What animals dominated the Mesozoic Era?

Petrified wood is an example of what type of fossil?

What important event in animal evolution marks the beginning of the Cambrian?

The current geologic period is called the ____.

The footprints of a dinosaur are an example of what type of fossil?

list the divisions of the geologic time scale in order from longest to shortest?

Which era immediately follows the Precambrian?

The era of “ancient life” is known as the ____.

The law of superposition states that an undeformed sequence of sedimentary rocks, each layer is

13. What is the currently accepted age of Earth?

Which period represents the last 2 million years of geologic time?

Mammals became dominant only after ____.

Which period makes up nearly all of the Cenozoic Era?

The Paleozoic era lasted about ____.

Which of the following must be true for a fossil organism to be useful as an index fossil?

Type of unconformity consists of tilted sedimentary rocks, that are then covered by new layers

The geologic processesthat operate today have also operated in the geologic past. .

The ____________________ is the era of “recent life” on Earth.

During the Pennsylvanian period, tropical swamps covered North America, eventually forming

The Tertiary Period lasted about ____________________ years.

The breakup of the supercontinent ____________________ occurred during the Mesozoic Era

Why did many plants die at the end of the Mesozoic?

Which of the following is important if an organism is to become a fossil?

What likely contributed to the extinction that marks the end of the Mesozoic Era?

____________________ tells geologists the sequence, or order, in which events occurred.

According to the principle of cross-cutting relationships, an intrusive rock body is

One group of reptiles, characterized by the fossil Archaeopteryx, led to the evolution of