Fossils and Earth's Early History

What can Paleontologists not determine from the fossil record

The absolute age of this type of rock can be determined using radioactive decay.

How much of Earths history falls into the Precambrian time

What do ice cores tell us? 

About 2.5 billion years ago, the first organisms capable of photosynthesis produced this.

Which is not an era on the geologic time scale?

Approximately how old is the Earth?

Which is older?

What type of rock is a fossil most likely found in? 

Which era did the Triasic period occur in?

What is the broadest (biggest) interval of time on the geologic time scale? 

Which layer is the youngest?

Geologists may be able to determine the absolute age of this rock

What is the relative age of rock?

The Velociraptor lived about 80 million years ago in this period

Which structures usually become fossils?

A land mass that was composed of the 7 continent we know today. 

Smilodon AKA Sabretooth Tiger, lived 12,000 years ago in this period

What rocks did scientists use estimate Earth's age to be about 4.6 billion years old?

*Tie Breaker: What GROUP on the periodic table contains Noble Gases? 

This type pf fossil forms when the bones remains of an organism leaves an imprint in sediment.

A trilobite is an example of an ______.

During the Permian and Triassic periods, the climate at the center of Pangea was

Fossils that do not provide an image of the animal, but provide evidence of its activities.

Each PERIOD on the geologic time scale represents _______.

Scientists have divided the history of the Earth into distinct intervals of time in the ______.

What type of fossil forms when sediment hardens in the space of a mold fossil?

About how long ago did the Cambrian period begin

This type of fossil when dissolved minerals replace the remains of an organism and form rock.

Which feature forms most recently?

The concept that Earth's processes today are the same as Earth's processes in the past.

After how many half lives does one sixteenth of the original amount of radioisotope remain?

The time period over which 50% or a radioactive isotope decays

When an organism leaves an extremely thin layer of carbon coating on rock.

What era are we currently in? 

Law of Superposition=

Radiometric dating=

If rock and sediment layers erode away, what is the boundary between disturbed layers called?

What isotope is often used to date organic matter less than 50 thousand years old?

Generally this part of an organism leaves a fossil

This type of organism lived in Precambrian Time

What isotopes are often used to determine the absolute age of rocks?