Lecture 29

Question 1

Resource cycle

Answer 1

1. Resources and raw materials
2. Mining, cultivating, and harvesting
3. Processing of raw materials
4. Transport of materials
5. Manufacturing of products
6. Transportation of products
7. Purchase and use by the consumer
8. Final Disposal

Question 2

Geochemically abundant elements comprise more than ___ of the crust

Answer 2

0.1%

Question 3

Geochemically scarce elements comprise less than ___ of the crust

Answer 3

0.1%

Question 4

Abundant metals

Answer 4

iron, aluminum, magnesium, manganese, titanium, silicon

Question 5

Scarce and rare metals

Answer 5

copper, lead, zinc, nickel, chromium, gold, silver, tin, tungsten, mercury, molybdenum, uranium, platinum, etc

Question 6

Non-metal resources are used for

Answer 6

chemicals, fertilizers, building, jewelry, and glass/ceramics

Question 7

Types of minerals

Answer 7

metallics and non-metallics

Question 8

Examples of metallic minerals

Answer 8

metals such as iron, aluminum, copper, gold, platinum, silver, etc

Question 9

Metallic minerals

Answer 9

those mined for constituent metals

Question 10

Nonmetallic minerals

Answer 10

those that we mine for their chemical or physical properties

Question 11

Examples of non-metallic minerals

Answer 11

sodium, sodium chloride, calcium sulfate (gypsum), calcium carbonate (calcite, aragonite), diamonds and emeralds

Question 12

Resource

Answer 12

a naturally occurring accumulation of material in concentrations and amounts that make extraction currently or potentially feasible

Question 13

Reserve

Answer 13

resources that can be exploited economically under present conditions

Question 14

mineral deposits

Answer 14

are localized concentrations of a resource

Question 15

ore deposits

Answer 15

mineral deposits that can be exploited economically

Question 16

Mineral deposits are derived from the following parts of the rock cycle:

Answer 16

1. magmatic concentrations of elements
2. hydrothermal concentration of elements
3. weathering and concentration of the residual material in place
4. by chemical sedimentary soncentration

Question 17

As the magma chamber cools, minerals begin to crystalize as a function of temperature, a process called _________.

Answer 17

fractional crystalization

Question 18

Crystals undergo gravitational ______ to the bottom of a magma chamber because they are ___ than surrounding magma

Answer 18

crystal settling

denser

Question 19

Crystal flotation

Answer 19

Where crystalized minerals are less dense than the magma and begin to accumulate

Question 20

Filter pressing

Answer 20

where much of the remaining magma moves through a fracture, leaving precipitated crystals behind

Question 21

Cumulates form through:

Answer 21

1. magma cools in fractional crystalization
2. crystals precipitate
3. crystals settle in a process called crystal settling

or

1. crystal flotation where crystals float because they are less dense
2. remaining magma moves through a fracture, leaving precipitated crystals behind

Question 22

How pegmatites form

Answer 22

excluded elements and water are concentrated in the last portion of the magma to crystalize, which makes a coarse grained pegmatite

Question 23

Pegmatite can be found in some _____

Answer 23

intrusions

Question 24

Pegmatites often contain:

Answer 24

unusual minerals and high concentrations of rare elements (Be, Li, Nb, Cs)

Question 25

Kimberlites

Answer 25

fragmented volcanic rocks from particularly explosive eruptions, where magma comes from the mantle beneath old/ stable continental lithosphere

Question 26

Kimberlites contain:

Answer 26

Variety of high-pressure minerals such as diamond

Question 27

Hydrothermal deposits:

Answer 27

A process where circulating groundwater is heated in volcanic areas and alters dissolved minerals. As the water moves away from the magma, it can cool, boil, or interact with oxygen and can reduce the solubility of dissolved metals causing them to precipitate. The heated water can also emerge from veins or fractures.

Question 28

Types of hydrothermal deposits

Answer 28

veins, stratiform deposits, or disseminate ores

Question 29

Vein hydrothermal deposit

Answer 29

fractures that have filled with mineral deposits

Question 30

Stratiform hydrothermal deposits

Answer 30

formed when hydrothermal water escapes to the seafloor and deposits a layer of mineral particles, resulting in volcanogenic massive sulfides deposits near current and former tectonic boundaries

Question 31

Disseminated ore hydrothermal deposits

Answer 31

Forms when hydrothermal water soaks through porosity in rocks and deposits mineral particles in pore spaces

Question 32

Residual deposits

Answer 32

Chemical weathering dissolves some components of rock, leaving behind more resistant material.

Question 33

Laterites

Answer 33

example of residual deposit (formed in tropical areas) and are rich in metals like nickel, aluminium, and iron

Question 34

Placer deposits

Answer 34

flowing water concentrating dense material in sands

Question 35

Black sands

Answer 35

rich in iron oxides are an example of placer deposits

Question 36

minerals that concentrate in placers include:

Answer 36

gold, platinum, zircons, rutile (titanium), diamonds, and cassiterite (tine)

Question 37

Aggregate

Answer 37

loose (exist as unconsolidated material) or can be crushed and sorted on site from a nearby rock

Question 38

Cement

Answer 38

formation of limestone, heated clay, and other sulfates/silicates

Question 39

Concrete

Answer 39

combining cement with sand and gravel

Question 40

Evaporite deposits

Answer 40

Chemical sedimentary rocks are formed by the evaporation of sea water and the subsequent precipitation of minerals from the solution.

Question 41

Important evaporites:

Answer 41

gypsum, halite (used on roads and human consumption), and potash (fertilizer/potassium)

Question 42

Banded iron formations

Answer 42

Sedimentary rocks (2 Ga and older) contain iron-rich formations (common iron ore deposits). This is sought to have occurred from the precipitation of Fe by oxygen production by cyanobacteria.

Question 43

Physical impacts of mining

Answer 43

volume of removed material may be difficult to replace, removal of plants can cause erosion, and erosion may contaminate streams

Question 44

Mine tailings

Answer 44

byproducts that remain after resources are extracted from the deposit

Question 45

Mine tailings and pyrite

Answer 45

Tailings piled on-site may be reactive when exposed to oxygen and water, when pyrite (FeS2) produce sulfuric acid (H2SO4) causing pH of surface and groundwater to be more acidic

Question 46

Impacts of Acid mine drainage

Answer 46

Mine drainage often contains elevated concentrations of potentially toxic heavy metals and presents a major threat to surrounding groundwater and surface water resources, aquifers, aquatic systems, and human health

Question 47

Smelting

Answer 47

a process used to extract target metal from the source ore which leads to a lot of greenhouse gases and acid rain.