Earth Science Chapter 8
Terms in this set (19)
A volcanic dyke would be most likely to illustrate this geologic principle.
Principle of cross cutting relations
What is the meaning of correlation as related to fossils?
Fossils can be used to match rock units in different areas
Which of the following is an example of numerical time?
The Silurian period began approximately 438 million years ago
Which of the following is not a characteristic of the geologic timeline?
Major subdivisions are equally spaced through geologic time
If such an isotope existed, which one would be best to use for establishing the age of archeological site that is about 50,000 years old?
One with a half-life of 20,000 yrs
This geologic time principle is usually associated with sedimentary rock units.
Principle of superposition
Who interpreted the Grand Canyon to be a result of long-lived geologic processes?
John Wesley Powell
Who first notice that fossil shark teeth found in rocks were similar to modern-day shark teeth?
What principle suggests that geologic processes that operate on Earth today are similar to those that operated in the past?
What feature is found when there is a time gap in the geologic record?
Unconformity in the rock unit
How old is the Earth?
About 4.6 billion years old
What data were used to develop the first geologic time scales?
The fossil record
How many eons are in the geologic time scale?
What is order of the Eons from oldest to youngest?
Archean, Proterozoic and Phanerozoic.
What is used to sub-divide the Phanerozoic into 3 eras?
It is divided by mass extinction events
Atoms with different numbers of neutrons in their nucleus are
What happens to amount of daughter isotope over time?
Which type rocks are best suited for numerical time dating?
Relative age-dating methods
allow Earth Scientists to determine if a specific rock layer is older or younger than rocks above or below it.