TEK 5.11B Draw conclusions about “what happened before ”using data such as from tree-growth rings and sedimentary rock sequences.

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

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

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

Th e correct answer is D. The sandstone is layered on top of the igneous rock formation, therefore the igneous rock formation must be older than the sandstone. The sandstone is layered on top of the igneous rock formation, therefore the igneous rock formation must be older than the sandstone.

These answers are incorrect because... In choices A, B, and C the igneous rock is under the sandstone so it could not be younger. In choices A, B, and C the igneous rock is under the sandstone so 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?

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

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

What story does this slice of the earth tell? shale Sedimentary layer Basalt (lava) tilted layers of limestone Pectin seashell fossils Fish fossils Fossil tree roots

A. Lava from a volcano first covered the area. Trees then grew on the land. Lastly, an ocean covered the area. B. An ocean first covered the area. The sea level then lowered and trees grew. Lastly lava from a volcano covered the land. C. Trees grew first on the land. Then the sea rose and killed the trees. Lastly, lava from a volcano covered the land. D. An ocean first covered the land. Then lava from a volcano covered the area. Lastly, trees grew on the land.

The correct answer is B. A n ocean first covered the area. The sea level then lowered and trees grew. Lastly lava from a volcano covered the land. Each layer is deposited in a certain order. The older the rock is, the deeper it will be in the crust. Since the oceanic layers are on the bottom, it must have been first. Each layer is deposited in a certain order. The older the rock is, the deeper it will be in the crust. Since the oceanic layers are on the bottom, it must have been first.

These answers are incorrect because... Although answer D begins with the oceanic layer it then places the volcanic layer second. Although answer D begins with the oceanic layer it then places the volcanic layer second. Answers A and C do not begin with the bottom layer of rock. Answers A and C do not begin with 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 1 10 meters deep Layer 2 20 meters deep Layer 3 30 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 B C. Fossil C D. Fossil D

The correct answer is C Fossil 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.