Relative Ages of Rocks
Absolute Ages of Rocks
Kinds of Rocks
Major Events in Earth's History
Geologic Time
100
This law states that newer rock layers tend to be found on top of older rock layers.
What is the Law of Superposition?
100
This is the approximate age of Earth.
What is about 4.6 billion years? (I will also accept 4.5 billion years)
100
This is the kind of rock that is formed from compressed fragments of smaller rocks and organic materia.
What is Sedimentary rock?
100
This is the name of the supercontinent that existed during the Paleozoic era.
What is Pangea?
100
This era makes up 88% of Earth's history.
What is Precambrian time?
200
These artifacts of Earth's history can help scientists determine relative ages of rocks, especially if certain index species are present.
What are fossils?
200
An atom is orbited by electrons. Name one kind of particle found in an atom's nucleus.
What are neutrons and protons?
200
This kind of rock is formed by cooled lava or magma
What is igneous rock?
200
Early in Earth's history all life on Earth existed in this place.
What are the oceans?
200
This is the era of Earth's history in which all of human history occurs.
What is the Cenozoic Era?
300
This is the name for when magma cools and hardens within the Earth's crust
What is igneous intrusion?
300
This is the amount of time it takes for half of a radioactive isotope to decompose to its stable form.
What is a half-life?
300
This kind of rock is formed by a physical or chemical change to another kind of rock.
What is metamorphic rock?
300
This is the variety of animal that became dominant in the Cenozoic era.
What are mammals?
300
This is the era when the dinosaurs lived.
What is the Mesozoic Era?
400
This is the name for when lava cools and hardens on the surface of the Earth.
What is Igneous Extrusion?
400
This is the source of the energy that makes Nitrogen in the atmosphere convert into the unstable isotope Carbon-14
What is the Sun?
400
Fossils are most commonly found in this kind of rock.
What is sedimentary?
400
This is the event that separates the Mesozoic Era from the Cenozoic Era.
What is the asteroid strike that killed the dinosaurs? (I would also accept the mass extinction event that killed the dinosaurs)
400
This era in Earth's history experienced an 'explosion' in the diversity of life forms on the planet.
What is the Paleozoic era?
500
This is the name for a break in the Earth's crust
What is a Fault?
500
Because of the rate of decomposition of Carbon-14, we can only use this isotope to find things up to this many years old.
What is 60,000 years?
500
While Carbon-14 is useful in dating fossils, other radioactive isotopes with longer half-lives are most commonly found in this kind of rock.
What is igneous?
500
This is the name of the time period we are living in right now.
What is the Quarternary Period?
500
Name one period in the Mesozoic Era.
Acceptable answers: Jurassic, Triassic, Cretaceious