Paleontology
Rocks and relative age
Rocks and relative age 2
Rock Decay

Earth History
100
Preserved remains or traces of organisms that lived long ago.
What are fossils?
100
A rock's age compared to the rocks and fossils around it.
What is relative age?
100
The name for molten rock that is below ground.
What is magma?
100
The process of analyzing percentages of radioactive isotopes within a rock sample to estimate its absolute age.
What is radioactive dating?
100

How are fossils dated?

Radiocarbon dating?

200
All of the information gathered by paleontologists about Earth's past.
What is the fossil record?
200
The number of years since a rock formed.
What is absolute age?
200
A layer of igneous rock formed when magma flows over the surface.
What is an extrusion?
200
The name for the amount of time it takes for half the atoms of a radioactive isotope to decay.
What is half life?
200

When sedimentary rocks are layered on top of older igneous rocks is called...?

Nonconformity

300
An organism's remains that have been unchanged for thousands of years.
What are preserved remains?
300
The compression of flat rock layers to form a series of arches and troughs.
What is folding?
300
The type of rock that you cannot find the absolute age of.
What is sedimentary rock?
300
The process that unstable isotopes go through that causes them to lose particles and energy.
What is radioactive decay?
300
Long ago the continents of Earth were all joined together to form _______.
What is Pangaea?
400
Fossils in which minerals replace all or part of an organism.
What are petrified fossils?
400
The fossil of a plant or animal that existed worldwide, but only during a certain geologic time period.
What is an index fossil?
400
Intrusions and extrusions must be _______ than the rock that they flow through.
What is younger?
400
______ Is how many half lives that have passed when an isotope has only 25% of its original atoms left.
What is 2?
400

What are the steps in the formation of a sedimentary rock?

weathering, erosion, deposition, cementation

500
A solid copy of the shape of an organism.
What is a fossil cast?
500
The scientific law which states that "In horizontal sedimentary rock layers, the oldest layer is the bottom layer and every layer above it is younger than the layer below it."
What is The Law of Superposition?
500
Gaps in the geologic record where both young and old rock layers meet. These are called _____________.
What are unconformities?
500
Atoms of the same element that have different numbers of neutrons.
What are isotopes?
500
"The continents of Earth were once joined together into a single super-continent but have since drifted apart, driven by the movement of Earth's lithospheric plates." (This is a theory)
What is the theory of continental drift?
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