Geography

Plate Tectonics & Boundaries - Crust Composition - Rock Types & Properties - Orogenesis & Subduction - The Rock Cycle - Metamorphic Processes - Rock Transformations

What drives the movement of tectonic plates?

Heat from the earth

What is a divergent plate boundary?

A boundary where plates move apart

What happens at a divergent plate boundary?

New crust is formed as magma rises

What is a convergent plate boundary?

A boundary where plates moves together

What is a subduction zone?

A zone where one plate sinks beneath another

What occurs when oceanic crust meets continental crust?

Earthquakes and volcanoes

What happens when two continental plates converge?

Earthquakes, but no subduction or volcanoes

Why do earthquakes occur at convergent boundaries?

Pressure build up from plate collision

Why are volcanoes common at subduction zones?

Melting of subducted crust creates magma

What are the two types of Earth's crust?

Oceanic and continental crust

Which type of crust is denser?

Oceanic crust

Which type of crust is thicker?

Continental

What is the average thickness of oceanic crust?

6 - 7 km

What is the average thickness of continental crust?

20 - 60km

What type of rock mainly composes oceanic crust?

Basalt

What type of rock mainly composes continental crust?

Granite

What is basalt?

A dense volcanic rock

Where is basalt mostly found?

Ocean floor

Why is basalt considered runny when molten?

Low silica content

What is granite?

A coarse-grained igneous rock

Where is granite mostly found?

Continents

Why is granite thicker when molten?

High silica content

What makes granite less dense than basalt?

Its mineral composition

What is the crystalline structure of basalt?

Coarse crystaline

What is orogenesis?

Mountain building

Where does orogenesis typically occur?

Subduction zones

What geological features are formed at subduction zones?

Mountains and volcanoes

What causes mountain building?

Plate collision and subduction

What is the rock cycle?

The continuous transformation of rocks

What is a rock?

A collaction of minerals

What is a mineral?

A single inorganic substance with a specific structure.

What are the three main types of rocks?

Igneous, sedimentary, medamorfic

How is igneous rock formed?

Magma or lava solidifying

What does "igneous" mean?

Fiery

How is sedimentary rock formed?

From compacted sediment

What is deposition?

Laying down of eroded material

What are biological sedimentary rocks made of?

Fossilized remains of organisms

How are metamorphic rocks formed?

Heat and pressure

What causes rocks to recrystallize?

Heat from the mantle

What causes rocks to deform?

Tectonic pressure

Which rock types can become metamorphic rocks?

Ignious and sedimentary

What is the process of metamorphosis in geology?

Transformation due to heat and pressure

How does limestone become marble?

Heat and pressure morph calcite-rich limestone into marble

How does sandstone become quartzite?

Sandstone recrystallizes into quartzite.

How does granite become gneiss?

regional metamorphism under intense heat and pressure

How does shale become slate?

Shale hardens into slate

What mineral is common in both limestone and marble?

Calcite