Show:
The Rock Cycle
The Relative Ages of Rocks
Radioactive Dating
Movement of Earth's Plates
The Geologic Time Scale
100
What does the Principle of Uniformitarianism state?
The Principle of Uniformitarianism states that the geologic processes that operate today also operated in the past.
100
What is the relative age of a rock?
The relative age of a rock is its age compared to the ages of other rocks.
100
What are the tiny particles that make up all matter?
Atoms.
100
What does the theory of plate tectonics state?
It states that the Earth's plates move slowly in various directions on an average of 5 centimeters per year.
100
What is the geologic time scale?
It is a record of the life forms and geologic events in Earth's history.
200
What are the three types of rocks?
Igneous rocks, Sedimentary rocks, and Metamorphic rocks
200
What is the absolute age of a rock?
The absolute age of a rock is the number of years that have passed since the rock formed.
200
What happens when all the atoms in a type of matter are the same?
An element has formed.
200
What does the theory of plate tectonics say about Earth's landmasses.
The theory of plate tectonics says that Earth's landmasses have changed position over time because they are part of plates that are slowly moving.
200
What are the basic units of the geologic time scale?
The two units are eras and periods.
300
In what general area do each of the three types of rocks form?
Igneous rocks form below Earth's surface. Sedimentary rock forms on Earth's surface. Metamorphic rocks form deep underground (beneath Earth's surface)
300
What is the Law of Superposition, and what does it help determine?
The Law of Superposition states that, in horizontal sedimentary rock layers, the oldest layer is at the bottom and each higher layer is younger than the layers below it. This law helps determine the relative ages of sedimentary rock layers.
300
What happens during radioactive decay?
During radioactive decay, the atoms of one element break down to form atoms of another element.
300
How has the movement of Earth's plates affected the evolution of living things?
As Earth's plates moved, landmasses changed their locations. These changes affected where different kinds of organisms, past and present, are located.
300
When did the earliest life forms form?
They formed in the Precambrian time.
400
What happens during the rock cycle?
Forces inside Earth and at the surface build, change, and destroy rocks.
400
How can you tell an igneous intrusion from an igneous extrusion?
Igneous intrusions are masses of igneous rock that have formed beneath Earth's surface while igneous extrusions are located on Earth's surface.
400
Why is the rate of decay of an element known as the element's half-life?
It is called the element's half-life because it is the time it takes for half of the element to decay.
400
The locations of what fossils show that Europe, Africa, and North America were once joined?
The locations of Brachiosaurus fossils.
400
In what era and period did the first dinosaurs evolve?
They evolved in the Triassic Period of the Mesozoic Era.
500
How do Igneous and Sedimentary rock become Metamorphic rocks?
They become Metamorphic rocks through heat and pressure.
500
How can a fossil be useful as an index fossil, and why are index fossils useful?
To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed only briefly. Index fossils are useful because they tell the relative ages of rock layers in which they occur.
500
What element is useful in dating the most ancient rocks? What does it decay to?
Potassium-40 is useful in dating the most ancient rocks. It decays to Argon-40.
500
What two landmasses did Pangaea break into about 180-200 million years ago?
The two landmasses were Laurasia and Gondwanaland.
500
What did the extinction of dinosaurs do?
The extinction of dinosaurs created an opportunity for mammals to thrive.