Chapter 13: Mineral and Rock Resources

Question 1

Resources

Answer 1

any useful economic commodity, one that also changes with time or context

Question 2

Reserves

Answer 2

portion of a resource that has been discovered and currently available to be extracted

Question 3

Sub economic Resources

Answer 3

deposits that have already been found but cannot be extracted profitably

Question 4

Hypothetical

Answer 4

deposits of a mineral in an area have been discovered and more are expected to be found

Question 5

Speculative

Answer 5

given certain geological conditions, a mineral deposit is expected to be found in a particular type of area, but no exploration has been done yet

Question 6

Ore

Answer 6

rock or metallic mineral that is economically worth mining

Question 7

Concentration factor

Answer 7

the concentration necessary for profitable mining determined as a ratio: concentration factor = concentration of the metal in the ore deposit / the average concentration of the metal in the crust

Question 8

Where are igneous rocks and magmatic deposits found?

Answer 8

commonly found along plate boundaries (areas with extensive magnetic activity)

Question 9

Pegmatites

Answer 9

rare, unusually coarse-grained igneous intrusions, that are known to produce single crystals over 10 m long, reflecting a very slow growth rate of the crystal

Question 10

Chromite and Magnetite

Answer 10

Heavy minerals sink to the bottom of a magma chamber as magma cools and minerals begin to crystallize. Minerals that form this way may concentrate at the bottom of a magma to be mined out later like gold and iron.

Question 11

Why are Diamonds so rare?

Answer 11

they are only created at very high pressures in the earth’s mantle and then brought up rapidly into the crust

Question 12

What is kimberlite and how it is formed?

Answer 12

is a kind of igneous rock which diamonds are mined from and forms large pipe-like intrusions that rise up from the mantle

Question 13

Hydrothermal Ores

Answer 13

copper, lead, zinc, gold, silver, platinum, uranium, sulfur is a common component

Question 14

How is a hydrothermal deposit formed?

Answer 14

fluids that seep into the cracks of surrounding rock are often super-heated and can leach out minerals and ions from the rocks through which they pass. As the fluids cool, they deposit their minerals, forming the hydrothermal deposit

Question 15

Sulfides

Answer 15

the ore minerals found in hydrothermal deposits

Question 16

Where are hydrothermal and igneous rock deposits commonly found?

Answer 16

found in areas with extensive magmatic activity (plate boundaries)

Question 17

Where do iron ore deposits come primarily from?

Answer 17

banded iron formations - world’s oldest known sedimentary rocks

Question 18

Banded Iron Formations

Answer 18

ancient deposits that consist of alternating layers of sedimentary rock and iron oxides. Initially formed in the sea, but are now found and mined above ground

Question 19

What are examples of our primary mineral resources?

Answer 19

salt, magnesium, and potassium: we consume over one billion tons per year

Question 20

Halite

Answer 20

the mineral salt which is mined from evaporite deposits

Question 21

Evaporite deposits

Answer 21

salt deposits that form when a body of shallow seawater gets “trapped” and dries up: the water evaporates and a layer of salt is left behind

Question 22

Gypsum

Answer 22

a mineral used in plaster, drywall, fertilizer, and chalk, another common evaporite minded mineral

Question 23

Placer Deposits

Answer 23

formed by flowing water, as the water velocity slows down minerals may overtime settle out and accumulate in these regions

Question 24

What is a famous example of a placer deposit?

Answer 24

Gold Rush in California was a placer deposit of gold draining from the Sierra Nevada mountains

Question 25

How do enriched ore deposits form?

Answer 25

form when soils are leached of their soluble ions, and the soil becomes more concentrated in what gets left behind (it becomes more concentrated in what is not leached out). This occurs in laterite soils, a soil found in tropical climates that has been leached of everything except for aluminum.

Question 26

Bauxite

Answer 26

an ore material to which aluminum is minded from, This ore is retrieved from laterite deposits

Question 27

Strip-mining

Answer 27

the mining process used to retrieve Bauxite which is found near the earths surface

Question 28

Metamorphic deposits

Answer 28

metamorphic rocks form as a result of rocks facing increasing amount of heat and pressure deep within the earth. Graphite, asbestos, and garnets are formed in and minded from these types of deposits

Question 29

What are the greatest metal mineral resources consumed in the US?

Answer 29

Iron - used for steel products
Aluminum - mined from bauxite, used in canning and construction industries
Copper - conductor of electricity, the main component in wiring
Zinc - used to coat steel cans to prevent rusting
Precious metals - gold, silver, platinum

Question 30

Nonmetallic Minerals

Answer 30

1) Sulfur - created as a by-product of mining sulfide minerals, and used by industry to create sulfuric acid
2) Halite, or salt, and gypsum

Question 31

Mineral supply and demand

Answer 31

supply and demand waxes and wanes depending on economic conditions and politics

Question 32

US Mineral Production and Consumption

Answer 32

the US consumes over 25% of the worlds silver and lead and roughly 20% of the worlds tin, gypsum, and nickel. The US imports minerals that it already produces in abundance

Question 33

How to preserve mineral resources?

Answer 33

minerals are nonrenewable resources, to preserve the resources consumption rates need to be reduced. Reducing consumption will keep reserve levels in check and would reduce mining pollution and waste disposal.

Question 34

Remote Sensing

Answer 34

a mapping technique, similar to radar, used by satellites and airplanes to detect and classify objects on the Earth and in the atmosphere, especially in places that are not easily reached on foot

Question 35

Marine Mineral Resources

Answer 35

as mineral reserves begin to dwindle, seawater and its deposits are being looked upon to make up for the gap

Question 36

Conversation of Mineral Resources

Answer 36

alternative to reducing reserve supplies by substituting a more abundant nonmetal for a metal product. Another alternative is recycling reduces waste, mining, and greenhouse gases.

Question 37

Two categories of surface mining?

Answer 37

open-pit mining and strip mining

Question 38

Open-pit Mining

Answer 38

-extracts rock either intact or crushed
-practical when the ore is located near the surface
-end product leaves a large hole, which may fill with water, which may then carry pollutants elsewhere
- sulfide minerals in the open pot mine react with oxygen and water to form sulfuric acid as a weathering product, creating acid runoff water

Question 39

Strip Mining

Answer 39

-commonly used to extract coal
-practical when ore is near the surface and runs in layered seams
-when mining operations are completed, the land is reclaimed and restored to habitable levels

Question 40

Mineral Processing

Answer 40

to extract a specifc metal from an ore can cause serious environmental problems. Processing involves crushing the ore. Waste minerals from this process are called tailings

Question 41

Tailings

Answer 41

waste minerals from mineral processing. Weathering of the tailings may produce acid drainage, similar to spoil banks of strip miners, and leach out harmful elements such as uranium, mercury, cadmium, and arsenic, that contaminate groundwaters

Question 42

heap-leaching

Answer 42

A process where cyanide solutions percolate through the tailing piles to dissolve the gold

Question 43

Smelting

Answer 43

extracts metal by using heat

Question 44

Downside of Smelting

Answer 44

the process produces sulfuric acid as a waste product gas, contributing to acid rain