Geology Of the Mantle

Question 1

Ultramafic Xenoliths

Answer 1

chunks of solid mantle carried upward as inclusions in lava

Question 2

Chemical reactions and quantum mechanics

Answer 2

Ultramafic Xenoliths

Question 3

Ophiolite

Answer 3

a chunk of seafloor that has been pushed up on land, we can detrmine the composition of the mantle by averaging it’s layers

Question 4

a chunk of seafloor that has been pushed up on land, we can detrmine the composition of the mantle by averaging it’s layers

Answer 4

Ophiolite

Question 5

layers of an ophiolite (bottom to top)

Answer 5

Hartzburgite, dunite, gabbro, sheet dikes, pillow bassalts

Question 6

Hartzburgite, dunite, gabbro, sheet dikes, pillow bassalts

Answer 6

layers of an ophiolite (bottom to top)

Question 7

Lherzolite

Answer 7

the forbidden rock we know exists, but can’t see, that makes up the upper mantle. Composed of Olovine, Orthopyroxine, and clinopyroxine

Question 8

the forbidden rock we know exists, but can’t see, that makes up the upper mantle. Composed of Olovine, Orthopyroxine, and clinopyroxine

Answer 8

Lherzolite

Question 9

Aluminum in the mantle

Answer 9

can’t be incorporated int Lherzolite, so insted it forms either plagioclase, spinel, or garnet depending on the conditions

Question 10

can’t be incorporated int Lherzolite, so insted it forms either plagioclase, spinel, or garnet depending on the conditions

Answer 10

Aluminum in the mantle

Question 11

Olivine collor in hand

Answer 11

olive green to greenish grey

Question 12

olive green to greenish grey

Answer 12

Olivine collor in hand

Question 13

olivine cleavage

Answer 13

poor cleavage, in both hand sample and thin section, thin section shows fracturing

Question 14

poor cleavage, in both hand sample and thin section, thin section shows fracturing

Answer 14

olivine cleavage

Question 15

Olivine habbit

Answer 15

either massive or drusty

Question 16

either massive or drusty

Answer 16

Olivine habbit

Question 17

olivine XPL

Answer 17

second order collors like a stained glass window

Question 18

second order collors like a stained glass window

Answer 18

olivine XPL

Question 19

clinopyroxene in thin section

Answer 19

bright 2nd order olors in XPL, has obvious cleavage

Question 20

bright 2nd order olors in XPL, has obvious cleavage

Answer 20

clinopyroxene in thin section

Question 21

Orthopyroxene in thin section

Answer 21

1st order colors n XPL with obvious cleavage

Question 22

1st order colors n XPL with obvious cleavage

Answer 22

Orthopyroxene in thin section

Question 23

pyroxenes in hand sample

Answer 23

nerely impossible to tell orthopyroxine and clinopyroxine appart, forms augite, tends to have hard to see 90 degree cleavage and never has twinning

Question 24

nerely impossible to tell orthopyroxine and clinopyroxine appart, forms augite, tends to have hard to see 90 degree cleavage and never has twinning

Answer 24

pyroxenes in hand sample

Question 25

Plagioclase in thin section

Answer 25

first order collros with high probability of twinning

Question 26

first order collros with high probability of twinning

Answer 26

Plagioclase in thin section

Question 27

plagioclase in hand sample

Answer 27

grey to black, twinning is visible in larger crystals, such as in abrodorite, as streaks when held up to light.

Question 28

grey to black, twinning is visible in larger crystals, such as in abrodorite, as streaks when held up to light.

Answer 28

plagioclase in hand sample

Question 29

Garnet in thin section

Answer 29

constantly extinct in XPL, clear in PPL with high relief

Question 30

constantly extinct in XPL, clear in PPL with high relief

Answer 30

Garnet in thin section

Question 31

Garnet in hand

Answer 31

has hackley fracture and a distinctive crystal shape, usualy red, but not reliably so

Question 32

has hackley fracture and a distinctive crystal shape, usualy red, but not reliably so

Answer 32

Garnet in hand

Question 33

spinel hand sample

Answer 33

Magnetite, easily identified by magnetic properties and oxidized metalic luster, tends to grow in oxtahedral shapes

Question 34

Magnetite, easily identified by magnetic properties and oxidized metalic luster, tends to grow in oxtahedral shapes

Answer 34

spinel hand sample

Question 35

Pyroxene silicate structure

Answer 35

single chains bound together by octahedral groups of the smaller catioic membe (Usualy magnesium) Larger cations glue the layers together

Question 36

single chains bound together by octahedral groups of the smaller catioic membe (Usualy magnesium) Larger cations glue the layers together

Answer 36

Pyroxene silicate structure

Question 37

exsolution in thin section (lamelle)

Answer 37

fracture lines appear large/bold, because that is where the unwanted stuff is being shoved

Question 38

fracture lines appear large/bold, because that is where the unwanted stuff is being shoved

Answer 38

exsolution in thin section (Lamelle)

Question 39

orthopyroxene composition

Answer 39

(Mg,Fe) Si2O6, also known as pidgeonite when a little calcium is added in

Question 40

(Mg,Fe) Si2O6, also known as pidgeonite when a little calcium is added in

Answer 40

orthopyroxene composition

Question 41

clinopyroxine composition

Answer 41

(Mg,Ca) Si2O6, also known as augite, may include some iron

Question 42

(Mg,Ca) Si2O6, also known as augite, may include some iron

Answer 42

clinopyroxine composition

Question 43

Lhersolite

Answer 43

a dense mixture of clino/.orthopyrocine and olivine that forms under high pressure, the olivine alighns it's c axis along with the direction of mantle convection

Question 44

a mix of clino/.orthopyrocine mixed with olivine

Answer 44

Lhersolite

Question 45

Olivine structure

Answer 45

(Mg,Fe)SIO4 Has a TOT structure similar to pyroxene, alhtough it's an ortosylicate instead of a chain. calcium glues the structures together

Question 46

(Mg,Fe)SIO4 Has a TOT structure similar to pyroxene.alhtough it's an ortosylicate instead of a chain. calcium glues the structures together

Answer 46

Structure of Olivine

Question 47

Structure of Garnet

Answer 47

(Ca, Fe, Mg,)3Al2(SiO4)3. has a TOT arrangement

Question 48

(Ca, Fe, Mg,)3Al2(SiO4)3. has a TOT arrangement

Answer 48

Structure of Garnet