Week Three Flashcards
(23 cards)
Earth crust is made up of different types of rocks with igneous rocks making up ______ of earth’s crust.
Igneous
Earth’s crust is made up of igneous, metamorphic and sedimentary _______.
rocks
Igneous comes from the latin word “Ignis” which means ________.
fire
Igneous rocks are associated with volcanic _______________.
eruption
Magma- is what comes out of volcanoes. It is hot liquid made of melted _____________.
minerals
When the hot liquid(magma) reaches earth’s surface it is known as ________.
Lava
The cooling and solidification of lave on the earth surface results in the formation of Extrusive igneous rocks (also known as volcanic __________)
rocks
When magma can’t come out and settles inside the surface, the magma cools slowly beneath the earth surface as it is completely surrounded by the soil and rock present there.
The cooling and solidification of magma within depth of the earth’s crust forms large ___________ which is known as Intrusive igneous rocks.
crystals
Igneous rocks has 2 types.
___________________ igneous rocks & Intrusive igneous rocks.
Extrusive
Igneous rocks are the 1st to be formed and are known as _______________ rocks.
primary
Pumice and Obsidian rocks are EXTRUSIVE igneous rocks.
Pumice is used for lightweight concrete.
___________rocks are used for ornaments(jewelry)
Obsidian
Granite and Diorite are INTRUSIVE igneous rocks.
_______ are used for building materials.
Both
Volcanoes-an eruption in the __________ crust.
Earth
Most Volcanoes are found mostly in- ______________or Constructive Plate margins.
Both margin ALLOWS gas and molten rocks to escape form inside the planet to the surface.
Destructive
Destructive(Convergent) Plate margin- Oceanic & continental plate move towards each other.
The denser oceanic plate _______ under the continental plate, melting down unto the earth’s mantle.
This melting releases gases that make there way to the crust above that erupt through the surface.
sinks
Constructive Plate margin (divergent)- the 2 plates move apart really slowly (less then 5 cm per year), but overtime this allows really hot magma to rise up from deep within the planets.
Magma rises then fills the gaps from the plates moving away from ach other.
Eventually a new crust is formed.
Magma at the margin sometimes can explode through this new crust. Creating a volcanic _____________.
Many of these constructive margins are found under the oceans.
eruptions
75% of the world’s active Volcanoes are along the Pacific Plate. It is referred to as the ring of _______.
Fire
Volcanoes can form away from tectonic boundaries.
They are called Hotspot volcanoes.
They form when rising magma form from deep within the planet melts through the tectonic plate above and begins to ______ ____.
Build up
2 types of volcanoes-
Composite Volcanoes:
&
__________ Volcanoes:
Shield
Composite Volcanoes:
(Known as Stratovolcanoes-
Strat means layers)
- majority of _____________.
-commonly found on destructive plate margins - distinctive conical shape
- bottom has a “magma chamber” like a hot bubbly furnace.
Magma enters the chamber from the earth’s mantle and collects here until pressure builds up gases to expand and water to become steam.
Eventually the pressure becomes so high that an explosion or a volcanic eruption occurs.
Most of the magma moves to the main vent and enters through the crater.
Some magma gets out through secondary vent and out through secondary cones.
volcanoes
Craters can eject 4 different materials at in the atmosphere-
________ (magma that has reached the surface of the earth), volcanic bombs(pieces of rocks), thick ash and gas
Lava
Shield Volcanoes-
- Usually found at Constructive Plate Margin or at hotspots
- Have gentle sloping slides caused by lava flowing quicker and covering longer distance before it solidifies.
Usually erupts less ______________ compared to composite volcanoes.
violently
Volcanoes reflect the movements of earth’s major tectonic __________ and signs of activity occurring under earth’s surface.
This gives us evidence that earth is full of powerful and dynamic fore
plates
