Geologic Time

Based on the law of superposition, where would the oldest rocks be found.

• at the bottom

• at the top

• second from the bottom

• second from the top

What is an unconformity?

• A layer of sedimentary rock

• A layer of rocks with unusual fossils

• An intrustion

• A missing time or gap in the rock record because of erosion

Carbon-14 can be used to date

• the death of organisms up to 10,00 years ago

• the death of organisms up to 60,000 years ago

• the death of organisms up to one million years ago

• all geologic events of the past

Which technique can be used to determine the exact age of a rock?

• Radiometric dating

• Relative dating

What are fossils?

• the oldest layers of rock in a region

• living creatures with habitats in or around rocks

• preserved remains or traces of once living things

• objects that people of long ago left behind as artifacts

Which letter matches with the OLDEST layer of rock?

• W

• X

• Y

• Z

The time that it takes 50% of an element to decay is called what?

• the daughter product

• the half-wit

• the half-life

• the half-time

What kind of rock would you typically find fossils in?

• igneous

• metamorphic

• sedimentary

Index fossils are used by geologists to

• match rocks of the same age in different regions

• determine the relative age of rocks in one place

• identify organisms that did not leave fossil evidence behind

• determine why some organisms became extinct

The age of a rock given as the number of years since the rock formed.

• relative age
• half-life
• absolute age
• radioactive decay