Quiz 11/17/2016 formation

Question 1

corundum

Answer 1

• meta of limestone or dolostone
• cooling of magma
• crystals form inside as the Al oxide cools

IG, SED, META

Question 2

hematite

Answer 2

-weathering/hydrothermal alteration of iron-bearing minerals

IG, SED, META

Question 3

ilmenite

Answer 3

• common accessory min in ig and meta
• crystallizes out of magma
• magmatic segregation occurs in layers
• pegmatites

IG, META

Question 4

magnetite

Answer 4

• very common accessory min found in ig and meta
• contact meta (ig intrusions) produces replacement deposits of magnetite

IG, META

Question 5

pyrolusite

Answer 5

• hydrothermal replacement deposits
• acid rich bogs

IG, SED, META

Question 6

spinel

Answer 6

• meta min in aluminous meta rocks
• regionally meta limestone and dolostone
• large scale heat and pressure

META

Question 7

graphite

Answer 7

• a result of decomposition of organic material deposited in the sediment
• in pelitic meta rocks; phyllite, slate, schist, marble

IG, META

Question 8

copper

Answer 8

• common in volcanics
• reaction between Cu-bearing/Fe-bearing solutions
• fills vesicles/cracks
• native Cu may be in oxidized zone of Cu-bearing hydrothermal sulfide deposits
• associated with chalcocite, bornite, epidote, calcite, chlorite, zeolites, cuprite

IG, SED, META

Question 9

molybdenite

Answer 9

• hydrothermal veins
• disseminated deposits
• pegmatites and porphyry Cu deposits

IG, META

Question 10

realgar/orpiment

Answer 10

-hydrothermal deposits with lead, silver, gold

IG, SED, META

Question 11

sphalerite

Answer 11

• common constituent of hydrothermal sulfide deposits
• can be an accessory min in felsic ig rocks/coral beds
• associated w/ galena, pyrite, chalcopyrite, pyrrhotite

IG, SED, META

Question 12

galena

Answer 12

• very common in hydrothermal sulfide deposits
• associated with sphalerite, pyrite, chalcopyrite, quartz, calcite, fluorite, barite
• used in automobile batteries

IG, META

Question 13

chalcopyrite

Answer 13

• most common in Cu-bearing minerals
• hydrothermal sulfide deposits
• found in some mafic rocks

IG, SED, META

Question 14

pyrrhotite

Answer 14

• common in high temp hydrothermal sulfide deposits and mafic/ultramafic ig rocks
• bodies formed (can be) by segregation of sulfide melt from silicate melt
• pegmatites
• associated with pyrite, marcasite, chalcopyrite

Question 15

pyrite

Answer 15

• most common sulfide mineral
• found in hydrothermal deposits
• ig rocks common
• common in shales and coal

IG, SED, META

Question 16

geothite

Answer 16

• weathering
• alteration of Fe-bearing minerals
• hydrothermal replacement deposits

IG, SED

Question 17

limonite

Answer 17

• alteration of iron min
• large masses of limonite produced by alteration and oxidation of pyrite in hydrothermal sulfide deposits
• weathering of Fe-bearing min

iron ore

Question 18

bauxite

Answer 18

• from soil that has been leached of silica
• secondary min forming in the weathered surface zones in clay deposits/limestones and low silica ig

IG, SED

Question 19

halite

Answer 19

• abundant in marine evaporite deposits
• found in saline lake deposits

SED

Question 20

sylvite

Answer 20

-evaporite deposits such as dry lakes and saline lake shorelines, salt beds and volcanic fumaroles

IG, SED

Question 21

fluorite

Answer 21

• hydrothermal ore veins
• sed deposits
• pegmatite dikes

IG, SED, META