Geologic Time Unit

What is the principle that states sediments are deposited in large, continuous sheets in all lateral directions?

• Lateral continuity

• Cross-cutting relationships

• Original horizontality

• Superposition

surfaces where rocks have eroded away producing breaks or gaps in the rocks recorded are called

• Superposition

• Inclusions

• Unconformities

• Key beds

What is a rock or sediment layer used as a marker, which is easy to recognize and correlates rock formations, and leaves important evidence in rock records?

• Key bed

• Index fossil

• Angular unconformity

• Lateral continuity

What is the term for a gap in the rock record during which new sedimentary rock formed on top of uplifted igneous or metamorphic rock layers?

• Nonconformity

• Disconformity

• Angular unconformity

• Cross-cutting relationships

What are the divisions of the geologic time scale from the smallest to the largest?

• Epoch, period, era, eon

• Era, period, epoch, eon

• Period, epoch, era, eon

• Eon, era, period, epoch

What is the basis for organizing the geologic time scale?

• Climate changes

• Rock and fossil records

• Ocean currents

• Volcanic activity

What must be present for an intrusion to occur in rock layers?

• Water

• Fossils

• Existing rock

• Soil

Why is it important to know if a layer has been folded when determining relative age?

• It affects the color of the rock

• It can cause the relative age to be interpreted incorrectly

• It changes the chemical composition

• It makes the rock more valuable

Which era is known for the appearance of mammals, ring of fire, and continental drift?

• Mesozoic

• Paleozoic

• Cenozoic

• Precambrian

During which era was earth formed and consisted of single celled things

• Precambrian

• Paleozoic

• Mesozoic

• Cenozoic