Earth History Investigation 4

Two students are exploring a creek in their neighborhood. The students hope to find some fossils along the way. What kinds of rocks should the students look for on their hike, and why should they look for those kinds of rocks?

• The students should look for igneous rock. This is the rock that comes from volcanoes and is melting hot. Fossils can form in the hot magma without burning up.

• They should look for metamorphic rock. These are the hardest rocks that have been under the most pressure for the longest amounts of time. Clearly the fossils will not have been crushes or ruined but preserved.

• The students should look for sedimentary rocks like shale, limestone, and sandstone. Fossils form when they are quickly covered by sediments in a basin.

• Fossils will not form in any of these types of rock. Fossils form in Fragile Rock.

Tags

NGSS.MS-LS4-1

What are reasons for gaps in the fossil record?

• Many organisms do not have structures that can be fossilized. (There bodies are made of soft tissues instead of shells or bones)

• Some environments do not provide conditions favorable to fossil formation. (If the environment is not made from sedimentary rock we will not have fossils.)

• There are lots of fossils that we haven't found yet. (Because you need to either dig or look in mountains we are still searching for many fossils/ index fossils to help us fill the gaps of the fossil record.)

• Some geological events destroyed fossils that were in the rock layers. (Things like earthquakes and volcanic eruptions may have destroyed important fossils).

• All of the above.

Tags

NGSS.3-LS4-1

Geological time is described in eras and periods. Those segments of time are based on ____________.

• whoever discovered them

• significant evolutionary events in Earth's history

• the thickness of certain rock layers

• the number of layers of rock that can be counted in 10 meters of a rock column.

Tags

NGSS.MS-ESS1-4

To a geologist, the most important use of index fossils is

• to show what kind of life existed long ago

• to show that sediments were deposited horizontally

• to determine the age of the rock

• to tell the story or the ancient environment

Geologists have discovered the fossils you see below in rock layers at two state parks. One of these fossils is an index fossil. Based on the information given, image from the picture is most likely the index fossil?

• A

• B

• C

• D

Tags

NGSS.MS-ESS1-4

Two students used the index fossil to analyze the rock layers. Student X claimed that Reservoir Limestone was older than Desert Sandstone. Student Y disagreed and claimed it was the opposite (Desert Sandstone is older than Reservoir Limestone). Which student do you agree, with and what is your evidence?

• I agree with student Y. The index fossil is found in Reservoir Limestone and Berkeley Limestone. If you line these two layers up, it becomes clear that Desert Sandstone is older, because it is below Reservoir Limestone.

• I agree with Student X. The index fossil is found in Reservoir Limestone and Berkeley Limestone. If you line these two layers up, it becomes clear that Desert Sandstone is older, because it is below Reservoir Limestone.

• I agree with Student Y. The Reservoir Limestone is older than Desert Sandstone because if you line these two layers up, it becomes clear that Reservoir Limestone is older because it is below Desert Sandstone.

• I agree with Student X. The Reservoir Limestone is older than Desert Sandstone because if you line these two layers up, it becomes clear that Reservoir Limestone is older because it is below Desert Sandstone.

Tags

NGSS.MS-ESS1-4

What are fossils?

• All the fossils on earth

• A fossil that characterizes a particular period of time.

• Any remains, trace, or imprint of animal or plant life preserved in Earth's crust.

• Fuel formed by natural processes over long periods of time.

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

What is the fossil record?

• A recorded device made out of fossils.

• A piece of music that is about fossils.

• A scroll that pictures all the fossils in North America.

• All the fossils on Earth.

Tags

NGSS.MS-LS4-1

What is an era?

• The largest division of geologic time.

• A subdivision of a geologic period.

• A broad span of geologic time based on the general type of life existing during that time.

• A community of organisms interacting with each other and with the nonliving environment.

Tags

NGSS.MS-ESS1-4

What is a period?

• A span of time within an era.

• A subdivision of a geologic period.

• A broad span of geologic time based on the general type of life existing during that time.

• A community of organisms interacting with each other and with the nonliving environment.

Tags

NGSS.MS-ESS1-4