Vocab
Absolute Age
Relative Age
Fossils
Earth
100
Ordering objects or events compared to other objects or events.
Relative Dating
100
The types of rocks that are best to use to find absolute age.
What is igneous rock?
100
The law that states the youngest rock layer is on the top and the oldest rock layer is on the bottom of an undisturbed rock sequence.
What is the law of superposition?
100
Fossils provide evidence of this about Earth's history.
What is life forms have changed over time?
100
The theory that changes on Earth occur suddenly over large areas and are short-lived, violent events.
What is catastrophism?
200
Determining the actual age of an object in years.
Absolute Dating
200
The method of finding the absolute age of a sample by determining the percentages of a radioactive parent isotope and stable daughter isotope.
What is radiometric dating?
200
The law that states a fault or body of rock, such as an intrusion, must be younger than any feature or layer of rock that the fault or rock body cuts through.
What is the law of crosscutting relationships.
200
Define fossils.
Fossils are the traces or remains of organisms that lived long ago.
200
The age of Earth.
What is 4.6 billion years?
300
A break in the geologic record when rock layers are eroded or when sediment is not deposited for a long period of time.
What is an unconformity?
300
The two pieces of information needed to determine the absolute age of a fossil or rock.
What is: half-life and the amount of radioactive material?
300
The two methods used to determine the relative age of rocks in a cross-section.
What is the law of superposition and the law of crosscutting relationships.
300
What two details can fossils tell us about Earth's past?
What is how the environment has changed over time and how life forms have changed over time.
300
Geologists description of geologic change as the same geologic processes that shape Earth today have happened throughout Earth’s history.
What is uniformitarianism?
400
A long cylinder of ice collected from an ice cap that gives the history of Earth’s climate over time.
What is an ice core?
400
The type of rock that scientists used to determine the absolute age of Earth.
What is a meteorite.
400
Order of the rock layers from OLDEST to YOUNGEST.
Oldest: C, G, A, P, W, N
400
The dating method used to determine the absolute age of fossils.
What is radiometric dating?
400
This divides Earth’s history into intervals of time defined by major events or changes on Earth.
What is the geologic time scale?
500
Magma (melted rock) which cools and becomes solid under the Earth's surface; cuts through rock layers.
What is an intrusion?
500
Calculate: A crystal contains a radioactive isotope that has a half-life of 5,000 years. You analyze a sample and find that one-sixteenth (6.25%) of the parent isotope remains. How old is the sample?
What is 20,000 years old?
500
The four ways in which rock layers can be disturbed.
What is: folding, faulting, intrusions, and tilting?
500
The four requirements for an index fossil.
What is: existed for a short period of time, distributed over a large area, relatively common, and has distinct features.
500
Scientist have determined an approximate age for Earth using this method of testing samples of rocks from the solar system.
What is Uranium-lead dating?