WorksheetsGEOTIME
Total questions: 20
Worksheet time: 10mins
According to the Principle of Cross-Cutting Relationships, igneous intrusions and faults are ALWAYS
deposited as sedimentary layers
older than rocks that it cuts across
younger than rocks that it cuts across
Which dating process places items in a comparison order (such as a red car is more expensive than a silver car)?
relative age dating
absolute dating
radiometric dating
In the Law of Superposition, in an undisturbed sequence of sedimentary rocks, the OLDEST layer is found
at the bottom of an outcrop
at the top of an outcrop
as a fault
An unconformity is a(n)
layer of sedimentary rocks
intrusion
layer of rock with index fossils
time gap in the rock record due to erosion
Fossils are the
oldest layers of rock in an area
remains or traces of once living things
creatures that live near or under rocks
The task of using fossils to match up rocks of similar ages in different locations is called
fossilization
succession
correlation
Index fossils allow geologists to
determine the relative age of rocks
identify organisms that did not leave fossil evidence behind
determine why some rocks weather faster
explain why some animals became extinct
The time it takes for 50% of the original unstable isotope (parent) decay to the stable isotope (daughter) is called
half-time
half-life
geotime
uranium
Using radiometric dating of igneous rocks provides
the relative age of the rock
the absolute age of the rock
What happened after the unconformity?
2
6
7
8
Carbon-14 dating is only used when
testing items older than 4.5 billion years
testing items younger than 60,000 years
items between 100,000 and 700,000 years
Which type of rock would fossils be in?
metamorphic
igneous
sedimentary
Which type of rock can we not date using radiometric dating?
metamorphic
igneous
sedimentary
What fraction of the original mass is left after 1 half-life?
1/2
1/4
1/8
1/16
What fraction of the original mass is left after 2 half-lives?
1/2
1/4
1/8
1/16
What fraction of the original mass is left after 3 half-lives?
1/2
1/4
1/8
1/16
Which radioactive isotope takes the shortest amount of time for a half-life?
Carbon-14
Uranium-238
Uranium-235
Potassium-40
What is the oldest in this picture?
A
B
C
D
E
What is the youngest in this picture?
A
B
C
D
E
The original unstable isotope is also known as the
parent
daughter
