Unit 3 Geologic Time and Fossils Review

Which phrase describes the relative age of a rock?

• uses the law of superposition to determine which rock is older or younger

• can determine the age based on location of a rock within the same layer

• requires only one rock to determine the age

• can provide the exact age of a rock

The image shows flat sedimentary rock layers in the foreground and angled sedimentary rock layers in the background. According to the principle of original horizontality, what most likely happened to the rock layers in the background?

• They cracked at an angle.

• They were deposited at an angle.

• They were deposited vertically and then shifted by a geologic event.

• They were deposited horizontally and then shifted by a geologic event.

Which feature causes a gap in the geologic record?

• extrusion

• fault

• intrusion

• unconformity

Tags

NGSS.MS-ESS1-4

The image shows cross-cutting relationships. B, W, E, and K represent rock layers, and Q represents a fault. Which statement describes the geologic features?

• Layer K is the oldest.

• Layer W is the youngest.

• Fault Q occurred before layer K was deposited.

• Layers B, W, and E were deposited after fault Q occurred.

Tags

NGSS.MS-ESS1-4

NGSS.MS-ESS2-2

The images show sedimentary layers before and after they were shifted by a geologic event. After the geologic event, which layer is the oldest?

• Layer A

• Layer B

• Layer C

• Layer D

Tags

NGSS.MS-ESS1-4

Which characteristic is shared by extrusions, intrusions, and faults?

• All are cracks.

• All are igneous rocks.

• All cause gaps in the geologic record.

• All are younger than the surrounding rocks.

How do index fossils help scientists?

• They aid in the study of ranges of different organisms.

• They advance understanding of the origin of life on Earth.

• They aid in comparison of rock layers at distant locations.

• They advance understanding of rock type at the time the organism lived.

A scientist finds a fossil that she thinks might make a good index fossil. Which characteristic does this fossil most likely have?

• It is the remains of an organism still found alive today.

• It is the remains of an organism that is found in abundance nearby.

• It is the only fossil for this type of organism that has ever been found.

• It is the remains of an organism that lived in a narrow geographic area.

Which information can be determined using half-life?

• age of material

• type of particle released

• percentage of rock that has aged

• number of radioactive particles left

Tags

NGSS.HS-PS1-8

After two half-lives, how much of the original material has decayed?

• 25 percent

• 50 percent

• 75 percent

• 100 percent

Tags

NGSS.HS-PS1-8