Fossils
The preserved remains or traces of living things
What is a fossil?
An extremely thin coating of carbon on rock
What is Carbon film?
the number of years that have passed since a rock formed
What is absolute age?
a landmass that existed when all continents were joined, from about 300 to 200 million years ago.
What was Pangaea?
Fossils in which minerals replace all of an organism or part of an organism such as a dinosaur bone
What is a petrified fossil?
A hollow area in sediment in the shape of an organism or part of an organism
What is a Mold?
the age of a rock compared to other rocks, i.e. older or younger than
What is relative age?
the time period between the Pre -Cambrian and present time period; Paleozoic, Mesozoic and Cenozoic
What are Eras?
Provides evidence of the activities of ancient organisms
What is a trace fossil?
A solid copy of the shape of an organism
What is a Cast?
when an organism no longer exists and will never again be on earth
What is extinct?
Eras that are subdivided. Many of the names come from places where fossils were discovered.
What are periods?
Scientists that study fossils
What is a Paleontologist?
A process that preserves entire organisms, i.e. tar, tree resin, freezing
What are Preserved Remains?
used to determine the relative age of a rock. It states that in undisturbed horizontal sedimentary rock layers the oldest is at the bottom Each higher layer is younger than the one below it.
What is the Law of Superposition?
elements that release particles of energy and they beak down or decay over time. Atoms of one element break down to form atoms of another element.
What is Radioactive Decay?
A fossil that is widely distributed and in existence for a relatively short period in geologic history. They are useful because they tell the relative age of the rock in which they are found.
What is an Index fossil?
It is the time it takes for a radioactive element for half of the elements to decay
What is Half-life?
a gap in the geological record that shows where rocks are lost due to erosion/ folding, etc...
What is Unconformity?
the key principle that guides scientists when they make inferences about Earth's past and is states that the geologic processed that operate today also operated in the past
What is Uniformitarianism?