Fossils and Geologic Time Flashcards
Name the material which comes from the sap of trees and usually insects become fossilized in:
Amber
This substance is oily and usually fossilizes entire organisms:
Tar
What harder parts of bodies can be easily fossilized?
Bones and Teeth
An intact wolly mammoth was found in this substance in Siberia:
Ice
These fossils were found over much of the Earth, but lived for a short period of time. They are very useful for identifying the relative age of rock layers.
Index fossils
These fossils only contain a trace of the original organism:
A footprint
What are fossils?
Traces, remains, or imprints of organisms
Do fossils form easily? Explain.
No, they have to be buried quickly.
Does a fossil always contain part of the original organism? Explain.
No, just a trace such as an imprint fossil
Which of these is an imperfect fossil?
A footprint
Which rock type contains the most fossils?
Sedimentary
By identifying different fossils in rock layers, scientists can determine the:
Relative age of the fossils
What is absolute dating?
It shows you how old a fossil is.
How many years ago did dinosaurs become extinct?
65 million years
What does the law of superposition state?
Youngest layer on the top, oldest on the bottom
The law is superposition is form of:
Relative Dating
Missing rock layers are called what?
Unconformities
What does the principle of cross-cutting relationships say?
Cross cut is the youngest
A fossil is MOST likely to be found in:
Shale
A fossil is NOT likely to be found in which of these rocks:
Basalt
Which rock type most often contains fossils?
Limestone
What are the fossils called which are used to determine the relative age of rock layers?
Index fossils
What substance is used to date the age of once living things?
Carbon-14
What is the outline of the major events in Earth’s geologic history?
Geologic time scale
