Earth's Timeline
What event marked the beginning of the universe 13-18 billion years ago?
What is the Big Bang?
What is Earth's outermost and thinnest layer?
What is the crust?
What is a naturally formed, inorganic solid with a crystalline structure?
What is a mineral?
What causes tectonic plates to move?
What are convection currents in the mantle?
What process turns magma into igneous rock?
What is cooling and crystallization?
How many years ago did Earth form?
What is 4.6 billion years ago?
Which layer makes up about 84% of Earth's volume?
What is the mantle?
What type of rock forms when magma cools and solidifies?
What is igneous rock?
What is the term for molten rock beneath Earth's surface?
What is magma?
What type of rock forms from the compaction and cementation of sediments?
What is sedimentary rock?
When did the first animals evolve?
What is 700 million years ago?
What two elements mainly make up the Earth's core?
What are iron and nickel?
Which element makes up 46.6% of Earth's crust?
What is oxygen?
What geological activity happens when tectonic plates collide?
What are earthquakes or mountain formation?
What breaks down rocks into smaller pieces?
What is weathering and erosion?
How long ago did dinosaurs go extinct?
What is 65 million years ago?
Which part of the mantle allows tectonic plates to move?
What is the asthenosphere?
What are the two main types of igneous rocks based on where they cool?
What are intrusive and extrusive rocks?
What are divisions in Earth's crust called?
What are tectonic plates?
What process involves extreme heat and pressure changing a rock's form?
What is metamorphism?
When did the first humans evolve?
What is 130,000 years ago?
Which layer generates Earth's magnetic field?
What is the liquid outer core?
Name the process that forms metamorphic rocks.
What is metamorphism?
Where can lava be found on the ocean floor?
What are mid-ocean ridges?
What is the continuous series of processes that change rocks from one type to another?
What is the rock cycle?