Geology 535 – Early Earth Evolution

Disclaimer: While every reasonable effort is made to ensure that the information provided is accurate, no guarantees for the currency or accuracy of information are made. It takes several proof readings and rewrites to bring the quiz to an exceptional level. If you find an error, please contact me as soon as possible. Please indicate the question ID-Number or description because server may randomize the questions and answers.

Go to: Final Exam

Geology (GLGY 535-UCAL) Midterm Exam

Please wait while the activity loads.
If this activity does not load, try refreshing your browser. Also, this page requires javascript. Please visit using a browser with javascript enabled.

If loading fails, click here to try again

Some questions have hints and explanations. Click Start to begin.

Start

Congratulations - you have completed Geology (GLGY 535-UCAL) Midterm Exam.

You scored %%SCORE%% out of %%TOTAL%%.

Your performance has been rated as %%RATING%%

Your answers are highlighted below.

Question 1

Modern day Mantle Potential Temperature (MPT) is ____ the Eruption Potential Temperature. (ID-EEM-32)

A	higher than
B	Could not answer the question because it is depend on the type of setting.
C	same as or very close to
D	lower than

Question 2

At the very beginning, solar nebula is made up of 71% what component or gas? (ID-EEM-36)

A	Rocks and dust particles
B	Water vapor
C	Hydrogen gas
D	Helium gas

Question 3

Which of the following is useful for estimating the abundance of soluble elements in the upper crust? (ID-EEM-43)

A	Sandstones
B	Loess
C	Shale
D	Limestone

Question 4

The iron sulphide phase in meteorites known as troilites (FeS) contains appreciable concentration of what other element? (ID-EEM-34)

A	Th
B	Sm
C	Nd
D	U
E	Pb

Question 5

Which of the following represents a normal order of condensation from a solar nebula gas as temperature decreases? (ID-EEM-46)

A	Silicates, metal oxides, volatiles
B	Volatiles, silicates, metal oxides
C	Any chemical group based on radial distance from the sun
D	Metal oxides, silicates, volatiles

Question 6

What is the simplest method to determine relative age of a luna crater? (ID-EEM-05)

A	Overprinting of craters with respect to each other.
B	Combination of geochemical and physical analysis of rocks from center and outer rim of the creator.
C	Geochemical analysis of rocks from the center of the creator.
D	Size and shape of the creator.

Question 7

Aristarchus lunar creator has typical characteristics of an impact creator. We found that the raised rim areas of the creator has been "eroded" or "disfigured". It is most likely caused by which of the following processes? (ID-EEM-01)

A	The raised rim is more susceptible to weathering.
B	Later impacts may have destroyed the raised rim.
C	Solar radiation and flares may have burnt out the thin and tall rim section.
D	Plate tectonics may have destroyed the original structure.

Question 7 Explanation:

Since moon does not have an atmosphere, you can rule out weathering. There are no plate tectonics. Therefore NASA scientists concluded, the only reason the raised rims are damaged because of later impacts that destroyed the original structure.

Question 8

Shield areas in continents are characterized by which of the following features? (ID-EEM-44)

A	Heat flux higher than in oceanic domains
B	Higher than average heat flux
C	Lower than average heat flux
D	Large variations in heat flux within a smaller area

Question 9

Why do we prefer to date zircons? (ID-EEM-10)

A	They have hardness of 5 in Mohs scale and therefore resistant to weathering.
B	It is easier to determine the isotopic compositions of zircons.
C	They are the most abundant mineral in cratons.
D	They have a very high closure temperature.

Question 10

Which of the following observation on differentiation is true? (ID-EEM-23)

A	During differentiation of Earth, large portion of silica sank into the core of the Earth.
B	Differentiation occurs at a extensive rate on larger plants.
C	Differentiation is highly dependent on the pressure conditions.
D	All meteorites are not differentiated because they are failed planets.

Question 11

Which of the following statement is false about Ordinary Chondrites? (ID-EEM-22)

A	Most of the Ordinary Chondrites have petrologic types from 3 to 6.
B	Ordinary Chondrites are the most common type we have today.
C	85% of all Ordinary Chondrites are observed falls.
D	75% of all Ordinary Chondrites contains CAIs and AOAs.

Question 12

Shot-lived isotopic systems are not suitable for studying which of the following situations? (ID-EEM-30)

A	To estimate relationships between cogenetic samples.
B	To analyze metal-silicate-sulfide differentiation.
C	To estimate timing of melting and crystallization sequences.
D	To estimate condensation temperatures of materials from Solar Nebula.
E	To analyze relatively short processes that occur for 300 million years.

Question 12 Explanation:

A typical short-lived isotopic system last for less than 100 million years. Therefore these systems cannot be used to analyze processes that takes longer than 100 Mya.

Question 13

A overall positive εHf value indicates... (ID-EEM-35)

A	...a mantle source.
B	...a crustal source.
C	...a system that has underwent gradual isotopic gain.
D	...an open system.
E	...a closed system.

Question 14

Where did we find the oldest known terrestrial Geologic martial on Earth? (ID-EEM-41)

A	Western Canada Sedimentary Basin, Canada.
B	Kaapvaal, South Africa.
C	Isua Formation, Greenland.
D	Jack Hill, Australia.

Question 15

Our Solar Nebula was as hot as 1500 K at one point. As it slowly cooled down, which of the following would you expect to condense first out of the gas cloud? (ID-EEM-25)

A	Silicates
B	Nobel gases
C	Aluminum
D	Ice
E	Metal oxides

Question 16

A overall negative εNd value indicates... (ID-EEM-19)

A	...a closed system.
B	...nothing because there is not enough information provided to answer the question.
C	...a crustal source.
D	...a mantle source.
E	...an open system.

Question 17

Chondrites have been classified into __I__ classes/types and the most common class/type, Ordinary Chondrites have __II__ groups/subtypes. (ID-EEM-21)

A	I. two II. four
B	I. three II. two
C	I. two II. five
D	I. two II. three
E	I. three II. three

Question 18

The variable patterns of REE abundances are interpreted to be caused by... (ID-EEM-26)

A	...high condensation temperature.
B	...repeated evaporation and condensation.
C	...high abundance in volatile elements.
D	...high abundance in refractory elements.

Question 19

In discordant analysis, the upper intercept provide what valuable information? (ID-EEM-13)

A	Crystallization age.
B	The closure conditions.
C	The time of formation.
D	Initial isotopic ratio.

Question 20

The MgO content of an erupted liquid is directly related to the ___ of the liquid arriving on the surface. (ID-EEM-40)

A	maximum temperature
B	electron affinity and reactivity
C	closure temperature
D	liquidus temperature
E	minimum temperature

Question 21

According our modern understanding of planetary sciences, where do most meteorites originate? (ID-EEM-37)

A	Asteroid belt
B	Sun
C	Venus
D	Moon
E	Comets

Question 22

Two isotopic systems of U-Pb were compared using isochron technique. One system had a large ratio of daughter isotopes compared to the parents. Which of the following statement is correct? (ID-EEM-18)

A	The system with large number of daughter isotopes ratio most likely have been undergone crustal or magmatic contamination.
B	The system with large number of daughter isotopes ratio most likely have a steeper isochron.
C	The system with large number of daughter isotopes ratio most likely have a shallower isochron.
D	The system with large number of daughter isotopes ratio most likely have been an opened system at some point.

Question 22 Explanation:

While it is possible, it is difficult to determine the state of a system using isochrons (open/close). It is also possible that the system may have be opened at some point. But, still it cannot be inferred simply by an isochron. Therefore, the only logical answer is the slope of the isochron itself. You have to apply the knowledge to answer this question.

Question 23

Which of the following was used by Claire Patterson to determine the age of Earth? (ID-EEM-47)

A	U-Pb dating of meteorites and pelagic sediment
B	U-Pb dating of ancient zircons
C	Nd model age dating of Isua Supracrustal lithologies
D	Hf-W dating of CAI inclusions
E	Pb-Pb dating of meteorites and pelagic sediment

Question 24

Which of the following element used in isotopic age calculations also plays a major role in zircon crystal lattice? (ID-EEM-24)

A	Hf
B	Sm
C	O
D	Si
E	Lu

Question 25

The Hf-W chronometer indicates that the core was formed... (ID-EEM-42)

A	...extremely slowly.
B	...rapidly.
C	...in several stages.
D	...inefficently.

Question 26

What is condensation temperature? (ID-EEM-16)

A	It is the temperature which 50% of a given element is condensed out of the nebula gas.
B	It is the temperature which 100% of all the elements are condensed out of the nebula gas.
C	It is the temperature which 50% of all the elements are condensed out of the nebula gas.
D	It is the temperature which 100% of a given element is condensed out of the nebula gas.

Question 27

When is the lower intercept of Pb-U concordia-discordia method provide no meaningful values? (ID-EEM-33)

A	If there is no upper intercept.
B	If most of the samples plots on the concordia.
C	If some samples plots on the concordia while others on discordia.
D	If the Pb-loss was episodic/continuous event.

Question 28

Which of the following element most likely the one to condensed out of the solar nebula first? (ID-EEM-20)

A	Cu
B	S
C	Mg
D	Al
E	Pb

Question 28 Explanation:

You should know this without memorizing all the refractory elements because CAIs in Chondrites.

Question 29

Majority of the mass in soar nebula is concentrated in... (ID-EEM-15)

A	...the Earth.
B	...in the core of the Earth.
C	...in the terrestrial planets.
D	...the sun.

Question 30

___ drives the plate tectonics. Choose the best possible answer. (ID-EEM-39)

A	Orogenic events
B	Interior temperature
C	Adiabatic decompression
D	Surface P-T conditions

Question 31

Which of the following can be used to establish the depleted of Earth’s mantle through time? (ID-EEM-49)

A	εW and εHf
B	εNd
C	εNd and εHf
D	εNd and εW
E	εW

Question 32

There are several criteria in classification of refractory elements. What is the most important parameter in refractory elements? (ID-EEM-17)

A	Silica content of the original source of the elements.
B	Volatility of the elements.
C	Type of reactivity and radioactivity of elements.
D	Very high condensation temperature.

Question 33

Which of the following contains the most refractory phases in chondritic meteorites? (ID-EEM-48)

A	Matrix
B	CAI’s
C	Metallic portion of the matrix
D	Nebula
E	Chondrules

Question 34

What is the primary factor contributed to core formation in Earth? (ID-EEM-28)

A	Gravitational separation of metallic iron from silicates.
B	Migration of molten Fe alloys along grain boundaries of solid silicates.
C	Chemical differentiation due to rapid exothermic reactions.
D	Differentiation of Fe alloys and silica due to high pressure and temperature conditions.
E	Heat produced by radioactive isotopes melting the bulk Earth.

Question 35

Which of the following statement best describes the studies done on surface compositions of the Earth's crust? (ID-EEM-31)

A	Over 50% of the data on major elements falls considerably outside of the range found by Eade and Fahrig's Canadian Shield Average.
B	Seismic evidence shows only two parts of the crustal sections; Middle and Lower. The Upper section is distinguished by elemental studies.
C	Major element data are consistent from study to study.
D	Trace element data are consistent from study to study.

Question 36

Given the following profile of a typical komatiite flow facies, where would you sample to estimate the composition of the original magma? (ID-EEM-29)

Facies	Profile	Zone
A1	Chilled flow top	Spinifex zone
A2	Random spinifex
A3	Plate spinifex
B1	-	Cumulate zone
B2	-
B3	-

A	Anywhere within the cumulate zone.
B	A1 in the chilled flow top region.
C	Anywhere within the spinifex zone.
D	A3 in the plate spinifex region.
E	B2
F	B1

Question 36 Explanation:

The highest (top) layer cool down faster hence preserving most of the geochemical properties of the original magma.

Question 37

What is Model Age? (ID-EEM-11)

A	It is the time of separation of isotope from a given reservoir.
B	It is a standard used to calculate type-sections and GSSPs for Geologic Time boundaries.
C	It is the time of primordial soup formation.
D	It is the time of crystallization.

Question 38

Steeper the Isochron, ___ the system. (ID-EEM-12)

A	larger the diffusion out of
B	younger
C	older
D	higher the uncertainties in
E	larger the diffusion into

Question 39

What are CI chondrites? (ID-EEM-27)

A	They are part of the differentiated group.
B	A type of chondrites with high abundance of silica and can be used to measure differentiation time period.
C	The most common chondrites that falls under petrologic Type 3.0 to 3.1
D	The most primitive chondrites that falls under petrologic Type 1.0

Question 40

There are several studies done on age of Earth. The calculated model ages are younger than the crystallization age (absolute age). (ID-EEM-14)

A	False because the model ages are older than the crystallization ages.
B	False because both model and crystallization age are the same. This is how we know the exact age of Earth.
C	Partially true because in most cases model ages are older than the crystallization ages.
D	True

Question 41

What is the oldest known radiometric date for Chrondrites as of October, 2014? (ID-EEM-38)

A	3.69 Ga
B	3.69 Ga
C	4.56 Ga
D	3.55 Ga
E	4.23 Ga

Question 42

Which of the following is the youngest era in the Archean timescale? (ID-EEM-45)

A	Neoarchean
B	Paleoarchean
C	Mesoarchean
D	Eoarchean

Question 43

What does the mass spectrometer actually measure? (ID-EEM-09)

A	Density of isotopes.
B	Alpha, beta and positron decay of isotopes.
C	Ratios of parent to daughter isotopes.
D	Weight and electrical charge of each isotope.

Question 44

Archean cratons have a deep lithopheric root. Most roots of these cratons exceed ____ km. (ID-EEM-06)

A	5
B	10
C	150
D	1000

Question 45

When studying Archean Geologic history, you should have a rough idea of the age of Archean cratons. What is a reasonable age range for an Archean craton? (ID-EEM-02)

A	3020 - 5560
B	542 - 2000
C	4500 - 4560
D	2500 - 4030

Question 46

Typically, what is the duration for a radioactive isotopic system? (ID-EEM-08)

A	4 half-life cycles.
B	5 half-life cycles.
C	8 half-life cycles.
D	14 half-life cycles.
E	13 half-life cycles.

Question 47

How is identification of cratons can be economically beneficial? (ID-EEM-07)

A	Majority of oil reserves were found in cratons.
B	Majority of food production ("farming") occur in cratonic regions.
C	Majority of the diamond-bearing kimberlites were found in cratons.
D	Majority of precious metals were found in cratons.

Question 48

The Ediacaran GSSP is primarily based on what type of evidence? (ID-EEM-03)

A	Fossil evidence
B	Sm-Nd dating
C	Refractory elemental abundance
D	U-Pb dating

Question 48 Explanation:

Specifically microfossils.

Question 49

Which of the following is useful for estimating the abundance of soluble elements in the upper crust? (ID-EEM-50)

A	Limestone
B	Loess
C	Shale
D	Sandstones

Question 50

Which of the following statement is correct about cratons? (ID-EEM-04)

A	There are only two places on Earth with creatons; Africa and North America.
B	The geochemical composition of creatons are homogeneous.
C	Within the creaton, platforms are areas where basement is overlaid by sediments and sedimentary rock.
D	Shield is a made up of several smaller creatonic nuclei.
E	Within the creaton, shield are areas where basement is overlaid by sediments and sedimentary rock.

Once you are finished, click the button below. Any items you have not completed will be marked incorrect. Get Results

There are 50 questions to complete.

←

List

→

Return

Shaded items are complete.

1	2	3	4	5
6	7	8	9	10
11	12	13	14	15
16	17	18	19	20
21	22	23	24	25
26	27	28	29	30
31	32	33	34	35
36	37	38	39	40
41	42	43	44	45
46	47	48	49	50
End

Return

Credits: Based on the excellent class notes provided by, Dr. Rajeev Nair during Fall 2014.
FAQ | Report an Error

You may download this exam as a PDF file here.

If you get a question wrong, you can still click on the other answers. This will open up hints and explanations (if available), which will provide additional information.

This class covers rapidly evolving subject matter. Due to cutting-edge research into Early Earth, there is a very high possibility that some of the questions may not be relevant to your current understanding. Please use this quiz with caution.

Sanuja Senanayake

Geology 535-University of Calgary

Go to: Final Exam

Geology (GLGY 535-UCAL) Midterm Exam

Standing on the shoulders of giants

Go to: Final Exam

Geology (GLGY 535-UCAL) Midterm Exam

Print/Share:

Standing on the shoulders of giants