Geologic Time Scale
The history of life and major events in Earth’s history
What does the Geologic Time Scale show?
Sedimentary rock
Fossils are most often found in which type of rock?
Tectonic plates
What are large pieces of Earth’s crust that move slowly over the mantle called?
Pangaea
What was the name of the supercontinent that existed millions of years ago?
Circular movements of heated material rising and cooling material sinking
What are convection currents?
The Mesozoic Era
Which era is known as the “Age of Dinosaurs”?
Rock strata
What is the term for the order in which rock layers were deposited over time?
Convection currents in the mantle
What causes tectonic plates to move?
Alfred Wegener
Who proposed the theory of continental drift?
In the mantle
Where do convection currents occur inside Earth?
The Cenozoic Era
Which era began most recently in Earth’s history?
The Law of Superposition
What principle states that older rock layers are found below younger layers?
Seafloor spreading
What forms new crust at mid-ocean ridges?
Matching fossils and rock layers on different continents
What evidence supports the idea of continental drift?
Heat from Earth’s core
What powers convection currents?
The Precambrian Time
What is the earliest and longest stretch of Earth’s history called?
How life has changed and evolved over time
What can scientists learn from the fossil record?
Convergent boundary
What type of boundary forms mountains like the Himalayas?
Plate tectonics
What process slowly moves continents apart today?
Hot rock rises and pushes plates apart, cool rock sinks
How do convection currents cause plates to move?
The appearance of complex life forms in the ocean
What major event marks the beginning of the Paleozoic Era?
The Theory of Plate Tectonics
What is the name of the theory explaining plate movement and related phenomena?
He couldn’t explain the force that moved the continents
Why was Wegener’s continental drift theory originally rejected?
Earthquakes, volcanoes, and continental movement
What can convection currents cause at Earth’s surface?