LESSON 1-5

Question 1

A molten material beneath or within the Earth’s crust from which igneous rocks are formed.

Answer 1

What is magma?

Question 2

A process in Earth’s crust where formation and movement of magma occur.

Answer 2

Magmatism

Question 2

1. Oxygen
2. Silicon
3. Aluminum
4. Iron
5. Calcium
6. Sodium
7. Magnesium
8. Potassium

Answer 2

Magma is made up of 8 elements

Question 3

Rocks begin to melt at a temperature between ___ and ____ degrees Celsius.

Answer 3

between 800 to 1200 degree Celsius

Question 3

Origin of Magma

Answer 3

Earth has 3 solid part and 1 liquid part in order for magma to form some part of the Earth must get hot enough to melt rocks.

Magma forms when rocks reach temperatures high enough to melt them.

Question 4

Processes that form magma by melting of mantle rock

Answer 4

• increase in temperature
• decrease in pressure
• addition of volatiles

Question 5

Increase in temperature

Answer 5

minerals in the rock have different melting point

Question 6

Decrease in pressure

Answer 6

Rocks beneath the earth remain solid when exposed to high pressure. During convection, rocks go upward, reducing the pressure.

Question 7

Addition of volatiles (water, gases)

Answer 7

adding of impurities like water and gas lower the melting point of rocks.

Question 8

Types of Magma Generation

Answer 8

Subduction zone
Hot spot volcanism
Magmatism along rift zones

Question 9

Formed through dry partial melting of mantle

Answer 9

Basaltic

Question 10

Formed through wet, partial melting of the mantle

Answer 10

Andesitic

Question 11

Formed as a result of wet melting of continental crust

Answer 11

Rhyolitic

Question 12

Factors that affects the viscosity of the magma

Answer 12

1. Temperature
2. Chemical composition/silica content
3. Amount of dissolved gases

Question 13

An eruption of molten rock, hot rock fragments and hot gases through a volcano, which is a vent in the Earth’s crust

Answer 13

Volcanic eruption

Question 14

Takes place when magma’s temperature get very high under the Earth’s surface

Answer 14

How volcanoes erupt

Question 15

Low gas content and low viscosity of magma (basaltic to andesitic magma) begin with fire fountains due to release of dissolve gases

Answer 15

Effusive/Non Explosive Eruptions

Question 16

High gas content and high viscosity (andesitic to rhyolitic magma)

Answer 16

Explosive Eruptions

Question 17

Hot fragments and volcanic ash which refer to sand or smaller fragments

Answer 17

Pyroclasts

Question 18

Four-and-a-half billion years ago. Earth formed from a cloud of gas and dust in space. Solid particles, called “planetesimals” condensed out of the cloud. They’re thought to have stuck together and created the early Earth. Bombarding planetesimals heated Earth to a molten state.

• The Earth was formed by the process of accretion a portion of the original heat was trapped inside the Earth’s crust and has not yet been lost.
• Meteoroids attracted each other and formed bigger masses. This process accumulated a lot of heat.

Answer 18

THREE MAIN REASONS WHY THE
INTERIOR OF EARTH IS VERY HOT
- The heat from when
the planet formed

Question 18

• Frictional heating, caused by denser core material sinking to the center of the planet.
• Some of the heat in the middle layers of the interior are hot because the deeper core is cooling and releasing heat.
• Earth is cooling now – but very, very slowly. Earth is close to a steady temperature state. Over the past several billion years, it might have cooled a couple of hundred degrees. Earth keeps a nearly steady
  temperature, because it makes heat in its interior.

Answer 18

THREE MAIN REASONS WHY THE
INTERIOR OF EARTH IS VERY HOT
- FRICTIONAL HEATING

Question 18

• It involves the decomposing of natural radioactive elements inside Earth – like uranium. Uranium is a special kind of element because when it decays, heat is produced. It’s this heat that keeps Earth from cooling off completely.
• Without this process of radioactive decay, there would be fewer volcanoes and earthquakes – and less building of Earth’s vast mountain ranges. This process contributes more than half of the heat in the earth.

Answer 18

THREE MAIN REASONS WHY THE
INTERIOR OF EARTH IS VERY HOT
- RADIOACTIVE DECAY

Question 19

is defined as the process by which magma get out through the crust and crystallizes as an intrusive igneous rock beneath the Earth’s surface. The name
plutonism references Pluto, the classical ruler.

Answer 19

Plutonism

Question 20

When magma forces itself into cracks, breaks off pieces of rock, and then envelops
them, this is called stoping. The resulting fragments are called _______. It is a piece of rock trapped in another type of rock

Answer 20

xenoliths

Question 21

A _____ is an intrusion of magma that wells up from below the surface. Pluton is a generic word for any igneous intrusive rock body

Answer 21

pluton

Question 22

_______ is a process where rocks, soil, and minerals are broken down into pieces.

Answer 22

Weathering

Question 23

The agents of weathering are water, ice, acids, salts, plants, animals, and changes in temperature whether it is cold or hot.

Answer 23

Agents of Weathering

Question 24

Sometimes called mechanical weathering, is the process that breaks rocks apart without changing their chemical composition. Happens especially in places where there is little soil and few plants grow, such as in mountain regions

Answer 24

Physical Weathering

Question 25

1. most important in the formation of soils 2. major forces that shape the Earth’s surface 3. an important part of the rock cycle 4. provides the sediments that form sedimentary rocks

Answer 25

Importance of Weathering

Question 26

This refers to the repeated freezing and melting of water within small narrow crack or space in the rock surface.

Answer 26

Frost Wedging or Freeze-Thaw