Earth science final sem 2

Question 1

How are sedimentary rocks created

Answer 1

By deposition, burial, compaction, and cementation. Form in oceans or lake bottoms where most sediments are deposited

Question 2

How are igneous rocks created?

Answer 2

Magma rising from the mantle. It forms above the surface (extrusive) or below the surface (intrusive)

Question 3

How are metamorphic rocks created?

Answer 3

Converging plates, contact with magma aka contact metamorphism, found under mountain ranges( highly folded units) and found around the edges of igneous intrusions

Question 4

What is the law of original horizontally?

Answer 4

All sedimentary rock layers and some extrusive igneous rocks are originally deposited in horizontal layers

Question 5

What is the law of superposition?

Answer 5

In undisturbed rock, the layers on the bottom are older than the layers above

Question 6

What is the law of disturbed rock strata

Answer 6

Any process which disturbs the rock must be younger than the rock it disturbs

Question 7

What is the law of crosscutting?

Answer 7

Any feature that cuts across layers of rock must be younger than all the rock layers it cut across

Question 8

What is tilting?

Answer 8

A type of disturbance that tilts rock layers and is caused by plate movement

Question 9

What is folding?

Answer 9

A type of disturbance that folds rock layers and is caused by plate movements

Question 10

What are the faults?

Answer 10

A fracture in the crust along with the lithosphere moves and is caused by plate movement

Question 11

What are intrusions

Answer 11

Magma that cuts onto rock layers and cools below Earth’s surface forming igneous rock which is caused by rising magma

Question 12

What is a dike?

Answer 12

Igneous rock intrudes along with fractures in existing rock (vertical/diagonal)

Question 13

What is sill?

Answer 13

Igneous rock intrudes along with sedimentary layers (horizontal)

Question 14

What is batholith?

Answer 14

A large mass of igneous rock with an irregular shape

Question 15

What is inclusion?

Answer 15

Parent rock breaks off into magma and does not melt and is found in the cooled igneous rock

Question 16

What is extrusion?

Answer 16

Molten rock that reaches Earth’s surface(lava) and cools forming igneous rocks and is caused by rising magma that reaches the surface

Question 17

What is uplift?

Answer 17

A type of disturbance that raises up a large area of the Earth’s crust and is caused by plate movement

Question 18

What is subsidence?

Answer 18

A type of disturbance that lowers a large area of Earth’s crust and is caused by plate movement of erosion

Question 19

What is unconformity?

Answer 19

A gap in the rock record where layers have been eroded and new layers have been deposited on top

Question 20

What are the steps to unconformity?

Answer 20

Deposition (This usually happens on the ocean floor below sea levels), Uplift (The sedimentary rock is lifted above sea level exposing it to erosion), Erosion and subsidence (Some of these layers are removed and the surface is lowered below sea level exposing it to deposition), and deposition (new layers are deposited where the missing rock was)

Question 21

What are fossils?

Answer 21

Preserved remains of organisms in rocks, primarily sedimentary

Question 22

What are index fossils?

Answer 22

Allow geologist to narrow the time of a rock unit to a specific time period

Question 23

What are the characteristics of an index fossil?

Answer 23

Distinctive features/easily recognizable, Widespread/ all over the world, Abundant/There are a lot of them everywhere, Hard parts or shells/Easy to preserve, and Short-lived/Not around for a long time

Question 24

What is absolute dating?

Answer 24

Quantitive (has an exact number), different than relative dating because it’s more exact

Question 25

What are radioactive isotopes

Answer 25

Allows us to absolutely date rocks which are done by looking at the ratio of radioactive (parent) isotopes vs stable (daughter) elements

Question 26

What is radioactive decay?

Answer 26

Unstable elements will become stable elements

Question 27

What are half-lives?

Answer 27

The amount of time it takes for half of a sample to decay

Question 28

What are the rules for radioactive dating

Answer 28

Heat, pressure and chemical composition don't affect decay. Radioactive isotopes decay at a constant rate. Different isotopes have different rates of decay

Question 29

What is an eclipse?

Answer 29

The blocking of light when one celestial body moves into the shadow of another celestial body

Question 30

What is a solar eclipse?

Answer 30

When the moon is blocking the sunlight to the Earth (New moon)

Question 31

What is a lunar eclipse?

Answer 31

When the Earth is blocking the moon from the sun (Full moon)

Question 32

What is a total eclipse?

Answer 32

An eclipse in which the whole disc of the sun or moon is covered. Occurs within the umbra (full shadow)

Question 33

What is the partial eclipse?

Answer 33

An eclipse in which part of the disc of the sun or moon is covered. Occurs within penumbra (partial shadow)

Question 34

Why do eclipses not occur every month?

Answer 34

The moon's orbit around the Earth is tilted 5 degrees compared to the Earth's orbit around the sun

Question 35

What are the different phases of the moon?

Answer 35

New moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and waning crescent

Question 36

What is waxing?

Answer 36

Moon phases when the illuminated portion grows. The right side is illuminated

Question 37

What is waning?

Answer 37

Moon phases when illuminated portion shrinks. The left side is illuminated

Question 38

Why does the same side of the moon always face the Earth?

Answer 38

The Moon's period of rotation is the same as its period of revolution

Question 39

What happens at apogee and perigee?

Answer 39

At apogee, the moon is farther and appears smaller. At perigee, the moon is closer and appears larger

Question 40

What is an orbit?

Answer 40

The path of an object around the sun

Question 41

What is the difference between perihelion and aphelion?

Answer 41

Perihelion points in orbit nearest to the sun. More gravitational attraction. Planets move faster in its orbit. Aphelion is the point in the orbit farthest from the sun. Less gravitational attraction. The planet moves slower in its orbit. Closer on Jan 3rd and farther on July 4th

Question 42

What is an ellipse?

Answer 42

An oval, an elongated circle with two centers called foci.

Question 43

What are foci and major axis?

Answer 43

Central points of an ellipse, the sun is always located at one of the foci and the major axis is the longest straight line distance across the eclipse. Passes through foci

Question 44

What is eccentricity?

Answer 44

The degree or flatness or ovalness of an eclipse