Dating of Rocks & Fossils

Dinosaurs first appeared during the Triassic period, and large mammals first appeared during the Tertiary period. Fishes with jaws first appeared before both dinosaurs and large mammals.

Using this information and the geologic time scale above, choose the period in which fishes with jaws first appeared.

• Cretaceous

• Quaternary

• Silurian

• Jurassic

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NGSS.MS-ESS1-4

Key examples of index fossils include several species of ________, which are an extinct group of marine animals whose hard-shelled bodies had three sections.

• trilobites

• sharks

• dinosaurs

• starfish

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NGSS.MS-LS4-1

A cast is a type of fossil that forms in the shape of an organism when

• sediment fills a mold and turns to rock.

• the organism's bones are preserved in rock.

• tree sap covers the organism and preserves it.

• minerals replace the organism's remains.

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NGSS.MS-LS4-1

On this geologic time scale, the following shapes have been place to represent a different fossilized organism. Each fossil has been dated to a single geologic period, as indicated in the diagram below.

Suppose the scientist has found each fossil in a rock formation that has not been disturbed by other geologic processes. Which order (youngest to oldest) did the scientist most likely find all of the fossils?

• Star, Square, Triangle, Circle

• Square, Star, Circle, Triangle

• Circle, Triangle, Square, Star

• Triangle, Circle, Star, Square

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NGSS.MS-ESS1-4

A rock strata in a specific location is shown above, with symbols representing different species:

• - A red triangle represents a species of marine crustacean.

• - A green circle represents a species of jawless fish.

• - A yellow square represents a species of tree moss.

• - A purple star represents a species of forest-dwelling insect.

The change shown in the diagram at the end of the Devonian geologic period could best be explained by:

• the environment changing from ocean to dry land.

• the arrival of a new predator in the ecosystem.

• the melting of a glacier and development of freshwater lakes and rivers.

• the environment changing from a cold climate to a warm climate.

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NGSS.MS-ESS1-4

Mildred collects a sample of fossilized plant material. She takes it back to her lab to run some tests on it. Mildred is able to measure the amount of carbon-14 in her sample and compare this to the amount of carbon-12 in it. She uses this information to calculate that the fossil is 4,500 years old. The process that Mildred used is known as _______.

• superposition

• faulting

• indexing

• radioactive dating

If the age of layer 4 is 400 million years and the age of layer 1 is 500 million years, then relative dating tells us the age of layer 3 is:

• between 400 million and 500 million years.

• older than 500 million years.

• 500 million years.

• younger than 400 million years.

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NGSS.MS-ESS1-4

The diagrams below represent rock layers found in two different locations by two different scientists. The scientist at location X used letters to label his rock layers, while the scientist at location Y used roman numerals to label her layers. Examine these diagrams and then answer the question that follows. Which layers are the same?

• Layers T and U are the same as layers VI and VII.

• Layers T and U are the same as layers I and II.

• Layers P, Q, R, and S are the same as layers IV, V, VI, and VII.

• Layers P, Q, R, and S are the same as layers I, II, III, and IV.

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NGSS.MS-ESS1-4

If a scientist knows the relative age of a fossil, he can also know

• how long the organism was alive.

• the relative age of the rock where it was found.

• the type of climate from which it came.

• how it became extinct.

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NGSS.MS-LS4-1

Which of the following is true about the age of rock layers and the age of the Earth?

• All rock layers are older than the Earth.

• The top layer in a sequence of rock layers is older than the Earth.

• The Earth is older than any rock layer.

• The bottom layer in a sequence of rock layers is older than the Earth.

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NGSS.MS-ESS1-4