Midterm Exam File Questions

Question 1

The largest of the “rocky” or terrestrial planets is…

Answer 1

Earth

Question 2

The most abundant three elements within Earth are

Answer 2

iron, oxygen, and magnesium

Question 3

Bodies in our solar system grew by the colliding of millions of bits of matter, this process is called

Answer 3

accretion

Question 4

As one result of accretion, bodies larger than about 500 km in diameter became very hot, perhaps molten, resulting in a gravity driven separation of material with different dentition. This is called…

Answer 4

differentiation

Question 5

The portion of Earth that is broken into tectonic plates is the

Answer 5

lithosphere

Question 6

Orogenic mountains form at or near

Answer 6

colliding plates

Question 7

The very first stars in the history of our universe would have differed from our sun (Sol) in that

Answer 7

they were larger and contained little except hydrogen and helium

Question 8

Small bodies of rock or metal that orbit Sol are called

Answer 8

asteroids

Question 9

Objects made of a mixture of ice and rock that orbit Sol are called

Answer 9

comets

Question 10

EArth’s lithosphere is composed of the

Answer 10

all of the crus and uppermost 100-150 km of mantle

Question 11

The Moho is the base of EArth’s

Answer 11

crust

Question 12

the age of oceanic crust___with increasing distance from the mid ocean ridges

Answer 12

increases

Question 13

The oldest lava (basalt) on the sea floor is about___

Answer 13

200 Ma

Question 14

Continental coastlines that occur within the interior of a tectonic plate are called

Answer 14

passive margins

Question 15

When rock is melted within the earth, resulting in volcanic activity, which statement is true about the melting

a) all material is melted
b) only a portion of the rock is melted–partial melting

Answer 15

b

Question 16

Melting at divergent plate boundaries is partly the result of

Answer 16

reduction of pressure

Question 17

Volcanic arcs have a direct geological relationship to

1) subduction
b) plate collision
c) oceanic trenches
d) all 3 of the above
e) none of the above

Answer 17

d

Question 18

A massive continental-scale glacier covered southern India and much of the land now south of the equator during the later part of the___Era

Answer 18

Palaeozoic Era

Question 19

Which is the oldest unit of the Geological Time Scale

Answer 19

Hadean

Question 20

Which is the youngest unit of the Geological Time scale

Answer 20

Cenozoic

Question 21

The oldest life forms on planet Earth lived during which time unit?

Answer 21

Archean

Question 22

Th last of the 3 major extinction events on Earth occurred at about

Answer 22

65 Ma

Question 23

The most significant of the 3 major mass extinction events on Earth occurred at about

Answer 23

245 Ma

Question 24

The process of plate tectonics results from___in EArth’s mantle

Answer 24

convection

Question 25

Which of the following is true about EArth’s mantle

Answer 25

It is solid except for small liquid patches

Question 26

Evidence indicates that Earth is about___old

Answer 26

4.5 Ga

Question 27

Modern astronomy indicates that the Big-Bang occurred at about

Answer 27

14 Ga

Question 28

One of the most important processes to take place after the Big-Bang and before the formation of our solar system was

Answer 28

the fusion of atoms inside large suns

Question 29

The condition of floating equilibrium of the lithosphere in the rest of the mantle is called

Answer 29

isostasy

Question 30

Although high variable, the average rate of movement of Earth’s tectonic plates is approximately

Answer 30

2 cm/year

Question 31

The deepest parts of the oceans occur

Answer 31

at convergent plate countries

Question 32

An isotope is

Answer 32

an atom with a specific number of protons plus a specific number of neutrons in its nucleus

Question 33

What is the depth of the base of oceanic crust

Answer 33

8 km

Question 34

What is the mantle/core boundary depth

Answer 34

2900 Km

Question 35

what is the centre of Earth depth

Answer 35

6400 km

Question 36

Earth’s asthenosphere is

Answer 36

a zone of weak roc in the lower part of the upper mantle

Question 37

the rate of 15O to 16 O in the shell of a marine planktonic organism can be used to determine

Answer 37

the temperature of the water in which the organism lived

Question 38

the most common type of meteorite (by far) is what is called ‘an ordinary chondrite’ One reason why their study is important to us is that

Answer 38

they seem to have the same chemical composition as Earth overall

Question 39

Regarding eArth’s atmospheric temperature (climate): in the geological past it has

Answer 39

fluctuated numbers times between ice ages and much water periods

Question 40

In the chemical classification of igneous rocks, which material is the most important

Answer 40

the silica content

Question 41

Imagine the following geological situation,a s determined fro a groups of rock strata in a tectonic mountain belt. A sequence of horizontal beds of clay and sandstone overlie a series of folded lava flows, displaying a number of anticlines an disinclines. The lava beds are all approximately 100 to 90 Ma, and the oldest of the sedimentary layers of 50 Ma, the youngest 35 Ma. The boundary between the lava and the sedimentary beds is called a (an)

Answer 41

angular unconformity