Igpet Final Multiple Choice

Front 1

For peraluminous rocks, which is correct?

1. Al2O3

2. Al2O3>CaO+Na2O+K2O

3. Al2O3Na2O+K2O

4. Al2O3

Back 1

2. Al2O3>CaO+Na2O+K2O

Front 2

Which choice is best for subalkaline basalts?

1. They can be olivine-bearing

2. They can be quartz-bearing

3. They can be olivine-bearing or quartz-bearing, depending on which side of the plane of silica saturation they plot

4. They cannot be quartz bearing

Back 2

3. They can be olivine-bearing or quartz-bearing, depending on which side of the plane of silica saturation they plot

Front 3

Which sentence is NOT correct?

1. Sodic series is a subgroup of alkaline series

2. Tholeiitic series is a subgroup of subalkaline series

3. Potassic series is a subgroup of alkaline series

4. Calk-alkaline series is a subgroup of alkaline series

Back 3

4. Calk-alkaline series is a subgroup of alkaline series

Front 4

Cu and Fe are respectively...

1. siderophile, chalcophile

2. chalcophile, siderophile

3. chalcophile, chalcophile

4. lithophile, chalcophile

Back 4

2. chalcophile, siderophile

Front 5

Under normal conditions, forsterite forms earlier than fayalite because ...

1. it is denser

2. magma has more Mg

3. Mg is smaller than Fe

4. Fe is used by pyroxene and magnettite

Back 5

3. Mg is smaller than Fe

Front 6

Distribution (Partition) Coefficient is :

1. CS/CL

2. CL/CS

3. CS/CS

4. CL/CL

Back 6

1. CS/CL

Front 7

Which element has higher partition coefficient in olivine?

1. Ni

2. V

3. Ti

4. Na

Back 7

1. Ni

Front 8

Which element(s) has/have higher partition coefficient in garnet?

1. Ni

2. V

3. Ti

4. Na

5. HREE

6. LREE

Back 8

5. HREE

Front 9

Among REE's, which element has higher partition coefficient in plag?

1. Lu

2. La

3. Sm

4. Eu

Back 9

4. Eu

Front 10

Which element is incompatible?

1. Na

2. Ca

3. Fe

4. Mg

Back 10

1. Na

Front 11

If partition coefficient (D) for an element is 1:

1. That element will partition toward solid phase

2. That element will partition toward liquid phase

3. That element will not partition between liquid and solid phases

4. That element would partition toward solid only in the early stage of crystallization

Back 11

3. That element will not partition between liquid and solid phases

Front 12

If partition coefficient (D) for an element is >>1:

1. That element will partition toward solid phase

2. That element will partition toward liquid phase

3. That element will not partition between liquid and solid phases

4. That element would partition toward solid only in the early stage of crystallization

Back 12

1. That element will partition toward solid phase

Front 13

If partition coefficient (D) for an element is <<1:

1. That element will partition toward solid phase

2. That element will partition toward liquid phase

3. That element will not partition between liquid and solid phases

4. That element would partition toward solid only in the early stage of crystallization

Back 13

2. That element will partition toward liquid phase

Front 14

By small degree of partial melting the concentration of compatible and incompatible elements in the melt would be respectively:

1. high, high if the melting materials are mafic

2. high, low

3. low, low if the melting materials are mafic

4. low, high

Back 14

4. low, high

Front 15

Which factor affects the behaviour of Eu in the melt?

1. fO2

2. pH

3. T

4. P

Back 15

1. fO2

Front 16

Why in REE diagrams, are the concentrations of REE's normalized to a standard?

1. To reduce the high values of some REE's

2. To increase the proportions of some REE's

3. To eliminate Oddo-Harkins effect

4. To produce a smooth pattern

Back 16

3. To eliminate Oddo-Harkins effect

Front 17

Negative Eu anomaly in REE diagram indicates that:

1. Magma originated from the mantle

2. Magma assimilated some crustal rocks during ascent

3. Plag fractionated from the magma

4. Eu was low in the source

Back 17

3. Plag fractionated from the magma

Front 18

Positive Eu anomaly in REE diagram indicates that:

1. Magma originated from the crustal source

2. Magma assimilated some crustal rocks during ascent

3. Eu was high in the source

4. The was plag in the source

Back 18

4. The was plag in the source

Front 19

The slope of LREE and HREE can be shown respectively by:

1. La/Sm, Tb/Lu

2. Tb/Lu, La/Sm

3. La/Eu, Sm/Lu

4. Sm/La, Eu/Lu

Back 19

1. La/Sm, Tb/Lu

Front 20

Island arcs and active continental arcs are respectively the result of:

1. ocean-ocean, ocean-continent subduction

2. ocean-ocean, ocean-ocean subduction

3. ocean-continent, ocean-ocean subduction

4. ocean-ocean, continent-continent subduction

Back 20

1. ocean-ocean, ocean-continent subduction

Front 21

Average vertical depth from the volcanic front to Beniof zone is ...

1. 200 km

2. 50 km

3. 110 km

4. 350 km

Back 21

3. 110 km

Front 22

Part of arc between volcanic front and trench is called

1. forearc

2. back-arc

3. volcanic front

4. volcanic arc

Back 22

1. forearc

Front 23

Which sentence is correct?

1. Volcanism is uniformly developed in island arc

2. Volcanism is continuous along island arc axis

3. Both compression and extension happen in a subduction zone

4. Thickness of the continental crust remains unchanged during subduction

5. The effects of crustal contamination is high in intra-oceanic arcs

Back 23

3. Both compression and extension happen in a subduction zone

Front 24

Which rock type is rare in island arc setting?

1. Basaltic andesite

2. Andesite

3. Dacite

4. Rhyolite

Back 24

4. Rhyolite

Front 25

What is the main magma series in island arcs?

1. Tholeiitic

2. Calk-Alkaline

3. Both above

4. Alkaline

Back 25

3. Both above

Front 26

Main differences between calc-alkaline and tholeiitic series?

1. SiO2, H2O content

2. MgO and volatiles

3. Fe, Si and volatiles

4. Evolution trend

Back 26

3. Fe, Si and volatiles

Front 27

Fractionation of which mineral should increase CaO/Al2O3 in the remaining melt?

1. Plag

2. CPX

3. OPX

3. Either plag or cpx depending on the magma series

Back 27

1. Plag

Front 28

Volcanic rocks of the Island Arc show:

1. Calc-alkaline trend

2. Tholeiitic trend

3. Alkaline trend

4. Both calk-alkaline and tholeiitic trends

Back 28

4. Both calk-alkaline and tholeiitic trends

Front 29

Which tectonic setting is the most intense area of magmatism?

1. convergent margin

2. mid-ocean rift

3. intraplate setting

4. continental rift

Back 29

1. convergent margin

Front 30

Which volcanic rocks do you expect to find in subduction zones?

1. basalt, andesite

2. andesite, rhyolite

3. andesite, rhyodacite, rhyolite

4. basalt, andesite, rhyolite

Back 30

4. basalt, andesite, rhyolite

Front 31

Which feature would be common in the Plag phenos of the andesitic rocks of subduction zones?

1. corroded/embayed margins

2. corona

3. oscillatory zoning

4. all of them

Back 31

3. oscillatory zoning

Front 32

Which sentence is correct?

1. There is no basalt associated with stratovolcanoes

2. Basalts are widespread but do not commonly erupt from stratos

3. Pyroclastic materials are less common in stratos

4. Stratos usually consist of predominantly dacitic lava

Back 32

2. Basalts are widespread but do not commonly erupt from stratos

Front 33

Which tectonic setting is more suitable for the formation of stratovolcanoes?

1. subduction zones

2. oceanic rifts

3. continental rifts

4. hot spots

Back 33

1. subduction zones

Front 34

By adding water, the position of the cotectic point shifts towards ... corner of the Olivine-Opx-Qtz system?

1. Qtz

2. Olivine

3. Opx

Back 34

2. Olivine

Front 35

The main difference between tholeiitic and calc-alkaline rocks is:

1. The presence of water in calc-alkaline/absence of water in tholeiite

2. Higher SiO2 in C.a.

3. Lower K2O in T.

4. Higher incompatible elements in C.a.

Back 35

1. The presence of water in calc-alkaline/absence of water in tholeiite

Front 36

Which ground preparation process is necessary for the formation of granitic rocks?

1. Thickening of the crust

2. Thermal disturbance

3. Mantle effects

4. All above

Back 36

4. All above

Front 37

What is the mantle's role in the production of granitic melts?

1. supplying heat

2. supplying material

3. supplying heat and/or material

Back 37

3. supplying heat and/or material

Front 38

Granites formed under low pressure and dry conditions are called;

1. subsolvus granites

2. hypersolvus granites

3. alkaline granites

4. calc-alkaline granites

Back 38

2. hypersolvus granites

Front 39

Granites formed under high pressure and high water content are called:

1. subsolvus granites

2. hypersolvus granites

3. alkaline granites

4. calc-alkaline granites

Back 39

1. subsolvus granites

Front 40

Color of Amphibole in PPL can help us determine relative content of:

1. OH

2. Ni

3. Ta

4. Ti

Back 40

4. Ti

Front 41

In which type of granite is muscovite common?

1. alkaline

2. calc-alkaline

3. aluminous

4. peralkaline

Back 41

3. aluminous

Front 42

In which type of granite can CPX be found?

1. peralkaline

2. calc-alkaline

3. aluminous

4. sodic

Back 42

4. sodic

Front 43

Opx-bearing granitoid is called:

1. benmorite

2. ankaramite

3. charnockite

4. mugearite

Back 43

3. charnockite

Front 44

In which type of granite would you find garnet, cordierite, sillimanite?

1. alkaline

2. calc-alkaline

3. aluminous

4. peralkaline

Back 44

3. aluminous

Front 45

Which granites are the result of extensive fractionation of MORBs?

1. I-type

2. S-type

3. Hybrid

4. Plagiogranites

Back 45

4. Plagiogranites

Front 46

What is the effect of volatiles in the position of minima (lowest T point) in the Qtz-Ab-Or system?

1. minima moves towards Ab-Or side

2. ... towards Ab-Qtz side

3. ... towards Qtz-Or side

Back 46

3. ... towards Qtz-Or side

Front 47

What is the common chemical feature of continental rhyolites?

1. metaluminous

2. peralkaline

3. peraluminous

4. peralkaline and peraluminous

Back 47

1. metaluminous

Front 48

Continental basalts are commonly:

1. alkaline

2. tholeiitic

3. calc-alkaline

4. mixed

Back 48

2. tholeiitic

Front 49

Wat type of basalt is predominant in ocean basins?

1. Alkaline

2. Tholeiitic

3. Calc-alkaline

4. Alkaline and tholeiitic

Back 49

4. Alkaline and tholeiitic

Front 50

What type of basalt is predominant in island arcs and mid-ocean ridges, respectively?
1. Alkaline, tholeiitic
2. Tholeiitic, alkaline
3. Calc-alkaline, tholeiitic
4. Alkaline, calc-alkaline

Back 50

1. Alkaline, tholeiitic

Front 51

Which mineral is not seen as phenos in tholeiitic basalt?

1. Opx

2. Cpx

3. Plag

4. Olivine

Back 51

4. Olivine

Front 52

Which mineral is not seen as phenos in Alkaline basalts?

1. Opx

2. Cpx

3. Plag

4. Olivine

Back 52

1. Opx

Front 53

Nodules are restricted to:

1. Alkaline basalt

2. Tholeiitic basalt

3. Calc-alkaline basalt

4. Alkaline and tholeiitic basalt

Back 53

1. Alkaline basalt

Front 54

Which sentence is correct?

1. Alkaline basalts and basanites are primitive because they have restite-rich nodules

2. Tholeiitic basalts are primitive because they have restite-rich nodules

3. Tholeiitic basalts are primitive because they don't have restite-rich nodules

4. Calc-alkaline basalts are primitive because they have restite-rich nodules

Back 54

1. Alkaline basalts and basanites are primitive because they have restite-rich nodules

Front 55

What is the oldest age of oceanic crust?

1. Archaen

2. Precambrian

3. Jurassic

4. Eocene

Back 55

3. Jurassic

Front 56

Divergent plate boundaries are usually ...

1. oceanic because specific gravity of oceanic crust is low

2. oceanic because specific gravity of oceanic crust is high

3. continental because specific gravity of oceanic crust is low

4. continental because specific gravity of oceanic crust is high

5. oceanic because oceanic crust is thinner

Back 56

5. oceanic because oceanic crust is thinner

Front 57

Which sentence is correct?

1. Fast-spreading ridges have broader range of compositions and a larger proportion of evolved liquids

2. Slow-spreading ridges have broader range of compositions

3. Composition of MORB in both fast and slow-spreading ridges are the same

4. MORB is completely uniform magmas

5. MORB is primary magma

Back 57

1. Fast-spreading ridges have broader range of compositions and a larger proportion of evolved liquids

Front 58

What is the source of T-MORB?

1. Depleted mantle

2. Enriched mantle

3. Mixing of N-MORB and E-MORB magmas

4. Mixing of enriched mantle magma with tonalitic basalt

Back 58

3. Mixing of N-MORB and E-MORB magmas

Front 59

Plag and garnet affect, respectively:

1. Sm, LREE

2. HREE, Eu

3. HREE, LREE

4. Eu, HREE

Back 59

4. Eu, HREE

Front 60

The most important enigmatic magmatism is associated with:

1. subduction zones

2. oceanic rifts

3. continental rifts

4. hot spots

Back 60

4. hot spots

Front 61

Seamounts are the result of volcanic activity in:

1. subduction zones

2. oceanic rifts

3. continental rifts

4. hot spots

Back 61

4. hot spots

Front 62

Which sentence is NOT correct?

1. Hot spots occur only in oceanic crust

2. Volcanic hot spots create linear chains

3. The source of magma in hot spots is the mantle

4. Both alkaline and tholeiitic basalts are formed in hot spots

Back 62

1. Hot spots occur only in oceanic crust

Front 63

In which tectonic setting is assimilation more common?

1. ocean-ocean subduction zones

2. oceanic rifts

3. continental rifts

4. hot spots

Back 63

4. hot spots

Front 64

Composition of magma in hot spots that occur at or near mid-ocean ridges would be:

1. hybrid of N-MORB and OIB

2. OIT

3. OIA

4. hybrid of E-MORB and OIB

Back 64

1. hybrid of N-MORB and OIB

Front 65

What is the age of the Large Igneous Provinces (LIPs)?

1. Jurassic

2. Eocene

3. Cretaceous

4. Archaen

Back 65

3. Cretaceous

Front 66

What is the principal magma series in the oceanic island setting?

1. alkaline

2. tholeiitic

3. calc-alkaline

4. both alkaline and tholeiitic

Back 66

4. both alkaline and tholeiitic

Front 67

Which sentence is NOT correct?

1. All alkaline rocks show the same evolution trend.

2. All subalkaline rocks show the same evolution trend.

Back 67

1. All alkaline rocks show the same evolution trend.

Front 68

The Plume Model is used to explain the formation of:

1. OIB

2. MORB

3. Calc-alkaline andesite in subduction zones

4. Alkaline and tholeiitic basalt formed in continental rifts

Back 68

1. OIB

Front 69

What is the ultimate source of EM and HIMU?

1. Depleted mantle

2. Enriched mantle

3. Ancient oceanic crust or sediments

4. Assimilation of continental crust

Back 69

3. Ancient oceanic crust or sediments

Front 70

In which tectonic setting do LMIs occur?

1. subduction zones

2. oceanic rifts

3. continental rifts

4. hot spots

5. any tectonic setting

Back 70

5. any tectonic setting

Front 71

Bushveld and Skaergard are examples of ... , respectively.

1. LMI, LMI

2. LMI, continental rift intrusion

3. continental rift intrusion, LMI

4. both hot spot related intrusions

Back 71

1. LMI, LMI