Geologic Time

Which of these numbers is closest to the age of the earth?

• 4,600 years

• 460,000 years

• 46 million years

• 4.6 billion years

Tags

NGSS.HS-ESS1-6

What is the main purpose of the geologic time scale?

• To organize the major eras of Earth's history

• To compare very short and very long periods of time

• To compete with other, non-geologic time scales

• To help people understand that the planet is really old

Tags

NGSS.MS-ESS1-4

Generally speaking, which rock layers are the oldest

• The thinnest ones

• The thickest ones

• The ones furthest from the surface

• The ones closest to the surface

Tags

NGSS.MS-ESS1-4

What can you conclude from the fact that there have been just four eons in Earth's history?

• Eons are very short periods of time

• Eons always last less than 1 billion years

• Geologists only began naming eons recently

• There have been at least eight periods in earth's history

What event might mark the end of a period?

• The fact that 100 million years had elapsed since the end of the previous period

• A major geologic change

• The appearance of one new species

• The gradual drifting of continents

Tags

NGSS.MS-ESS1-4

How would the human time scale be different if we measured it in relative, instead of specific, time?

• Days would be longer than months

• One week might be longer or shorter than the next

• No one would know what time it was

• The future would occur before the past and present

How does radiometric dating differ from the ages of the geologic time scale?

• Radiometric dating involves absolute dates; the geologic time scale is measured with relative dates

• Radiometric dating can only be used on fossils; the geologic time scale applies only to rocks

• Radiometric dating involves unstable, radioactive isotopes; the geologic scale deals only with stable rocks and compounds

• Radiometric dating involves relative dates; the geologic time scale is measured with absolute dates