Banded Iron Formations Flashcards

1
Q

Iron and steel production is annually worth

A

US$400Bn

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2
Q

Iron and steel production is annually worth

A

US$400Bn

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3
Q

Carbon steel

A
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4
Q

Ch steel properties

A

Hardness, anti-corrosion

Brittle

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5
Q

minor types of iron deposits [4]

A

iron stones
magmatic iron
placer
contact metasomatic

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6
Q

iron stones

A

replace CO3 by Fe-Rich groundwaters

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7
Q

Magmatic Iron

A

e.g. mexico

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8
Q

Contact metasomatic

A

igneous intrusions and limestones

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9
Q

place

A

iron sands erosion of volcanic rocks

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10
Q

two major types of iron

A

Algoma BIF archean

Superior-type BIF MOST IMP

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11
Q

Carbon steel

A
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12
Q

Ch steel properties

A

Hardness, anti-corrosion

Brittle

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13
Q

minor types of iron deposits [4]

A

iron stones
magmatic iron
placer
contact metasomatic

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14
Q

iron stones

A

replace CO3 by Fe-Rich groundwaters

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15
Q

Magmatic Iron

A

e.g. mexico

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16
Q

Contact metasomatic

A

igneous intrusions and limestones

17
Q

place

A

iron sands erosion of volcanic rocks

18
Q

two major types of iron

A

Algoma BIF archean

Superior-type BIF MOST IMP

19
Q

three types of formation process

A

a) oxygenic photosynthesis - redoxcline
b) direct biological oxidation - iron chemocline
c) UV induced oxidation - iron chemocline

20
Q

BIFs alternate between

A

Fe-rich dark

Silica rich white/red/jasper/chert

21
Q

6 stages of iron formation

A
○ Upwelling and hydrothermal
		○ Oxidized Fe III as closer to surface
		○ Changes to iron carbonates as precipitated out
		○ Forms superior or alg.
		○ Transport of iron as Fe2+
		○ Precipitation on oxidation to Fe3+
22
Q

important iron regions

A

Hamersley ranges of Australia, Carajas, Brazil.

23
Q

iron layers [4]

A

Fe-oxides – magnetite, hematite
Fe-sulfides – pyrite, pyrrhotite
Fe-carbonates – siderite
Fe-silicates – Fe-rich talc, chlorite,