TEK 5.11BTEK 5.11B

Draw conclusions about Draw conclusions about “what happened before “what happened before ”using data such as from ”using data such as from tree-growth rings and tree-growth rings and sedimentary rock sedimentary rock sequences.sequences.

The diagrams that follow The diagrams that follow represent two different represent two different geologic cross sections in geologic cross sections in which an igneous formation which an igneous formation is found in sedimentary is found in sedimentary rock layers. The layers rock layers. The layers have not been overturned.have not been overturned.

Study the two cross Study the two cross sectionssections..

What What conclusions conclusions could be drawn could be drawn about the about the deposition of deposition of the igneous the igneous formation in the formation in the overlying overlying sandstone in sandstone in the two the two diagrams?diagrams?

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A.A. In A, the igneous rock is younger than the sandstone and In A, the igneous rock is younger than the sandstone and in B, the igneous rock is older than the sandstone.in B, the igneous rock is older than the sandstone.

B.B. In A, the igneous rock is older than the sandstone and in In A, the igneous rock is older than the sandstone and in B, the igneous rock is younger than the sandstone.B, the igneous rock is younger than the sandstone.

C. In both A and B, the igneous rock is younger than the C. In both A and B, the igneous rock is younger than the sandstone.sandstone.

D. In both A and B, the igneous rock is older than the D. In both A and B, the igneous rock is older than the sandstone.sandstone.

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TThhe correct answer is e correct answer is DD..

The sandstone is layered The sandstone is layered on top of the igneous on top of the igneous rock formation, therefore rock formation, therefore the igneous rock the igneous rock formation must be older formation must be older than the sandstone.than the sandstone.

These answers are incorrect These answers are incorrect because...because...

In choices A, B, and C In choices A, B, and C the igneous rock is the igneous rock is under the sandstone so under the sandstone so it could not be younger.it could not be younger.

limestone

shale

sandstone

Basalt (lava) tilted layers of limestone

Pectin seashell fossils

Turitella and ammonite fossils

Fish fossils

Which layer of rock contains the youngest fossil remains?

Which layer of rock contains the youngest fossil remains?

A.shaleB.limestoneC.tilted layers of limestoneD.sandstone

The correct answer is C: tilted layer of limestone

The tilted layer of limestone is layered on top of the other formations, therefore it must be younger than the other layers of rock.

These answers are These answers are incorrect because...incorrect because...

In choices A, B, and D the In choices A, B, and D the shale, limestone, and shale, limestone, and sandstone is under the sandstone is under the tilted layers of limestone tilted layers of limestone so they could not be so they could not be younger.younger.

The next slide represents a The next slide represents a drawing that consists of four drawing that consists of four underground rock layers. The underground rock layers. The top layer is a volcanic rock top layer is a volcanic rock called basalt. The next layer is called basalt. The next layer is a sedimentary layer called a sedimentary layer called shale with tree-root fossils. shale with tree-root fossils. The bottom two layers are The bottom two layers are oceanic layers, which contain oceanic layers, which contain fish and seashell fossils.fish and seashell fossils.

What story does this slice What story does this slice of the earth tell?of the earth tell?

shale

Sedimentary layer

Basalt (lava)

tilted layers of limestone

Pectin seashell fossils

Fish fossils

Fossil tree roots

A.A. Lava from a volcano first covered the area. Trees Lava from a volcano first covered the area. Trees then grew on the land. Lastly, an ocean covered the then grew on the land. Lastly, an ocean covered the area. area.

B.B. An ocean first covered the area. The sea level then An ocean first covered the area. The sea level then lowered and trees grew. Lastly lava from a volcano lowered and trees grew. Lastly lava from a volcano covered the land.covered the land.

C.C. Trees grew first on the land. Then the sea rose and Trees grew first on the land. Then the sea rose and killed the trees. Lastly, lava from a volcano covered killed the trees. Lastly, lava from a volcano covered the land.the land.

D.D. An ocean first covered the land. Then lava from a An ocean first covered the land. Then lava from a volcano covered the area. Lastly, trees grew on the volcano covered the area. Lastly, trees grew on the land.land.

The correct answer is B.The correct answer is B.AAn ocean first covered the n ocean first covered the area. The sea level then area. The sea level then lowered and trees grew. lowered and trees grew.

Lastly lava from a volcano Lastly lava from a volcano covered the land.covered the land.

Each layer is deposited in a Each layer is deposited in a certain order. The older the certain order. The older the rock is, the deeper it will be in rock is, the deeper it will be in the crust. Since the oceanic the crust. Since the oceanic layers are on the bottom, it layers are on the bottom, it must have been first. must have been first.

These answers are These answers are incorrect because...incorrect because...

Although answer D begins with the Although answer D begins with the oceanic layer it then places the oceanic layer it then places the volcanic layer second.volcanic layer second.

Answers A and C do not begin with Answers A and C do not begin with the bottom layer of rock.the bottom layer of rock.

On a construction site, workers revealed several layers of rock and soil. In the soil, fossils were found and recorded at each layer. Then scientists made the diagram to show the types of fossils and where they were located.

Review the following table and determine which fossilized organism is the youngest.

Layer 110 meters deep

Layer 220 meters deep

Layer 330 meters deep

•Fossil A

•Fossil B

•Fossil C

•Fossil D

Review the following table and determine which fossilized organism is the youngest.

Which fossilized organism is the youngest?

A.Fossil A B.Fossil BC.Fossil CD.Fossil D

The correct answer is CFossil C

The layer at the top is the youngest layer of rock. Therefore, fossil C is the youngest fossil.

These answers are incorrect because...

Fossils A, B, and D can be found on layers 2 and 3, which are older than Layer 1.