Rock and Minerals

ROCKS AND MINERAL

RESOURCESGeology

The Walker School

Essential Questions

What elements are important for our society?

What is the average crustal content of common

minerals?

To what extent must a metal be concentrated above

its average crustal content to make mining it

economically viable?

Rocks

A rock is an

aggregate of one or

more minerals.

There are over a

1,000 different types

of rocks on Earth.

Rock Classifications

Physical Properties

Chemical Composition

Specimen of Tourmaline and Quartz

Rock Formation Cycle

WHAT MINERALS ARE

IMPORTANT TO OUR

SOCIETY?

Minerals

A mineral is a naturally

occurring, inorganic

solid with an orderly

crystalline structure and

a definite,

homogeneous chemical

composition.

Medieval Manuscripts

Much of the ink used in

these brilliantly colored

manuscripts came from

various minerals.

Economically Important Minerals

Aluminum

Coal

Copper

Iron

Lead

Salt

Tin

MATTER, ELEMENTS, AND

BODING

Periodic Table of Elements

Fig. 3-4, p. 74

Types of Bonds

Ionic Bonds

Covalent Bonds

Metallic Bonds

Van Der Waals BondsIncrease

In

Bond

Strength

Ionic Bonds in Minerals

Fig. 3-6a, p. 76

Covalent Bonds

Fig. 3-7, p. 76

Covalent Bonds in

Graphite

Covalent Bonds in

Diamonds

Sheering

TO WHAT EXTENTS MUST A

MINERAL BE CONCENTRATED

TO BE ECONOMICALLY

VIABLE?

Common Elements in Earth’s Crust

Fig. 3-11, p. 80

Mineral Contents of Common Rocks

About 0.0001 to 0.008 weight percent of copper,

lead, zinc and tin

About 0.00001 to 0.000002 weight percent of

platinum, silver, and gold

About 6.0 weight percent of iron

Economic Determinants of Viable Mineral Deposits

Mining Technologies

Market Value

Economically Viable Deposits

25 x crustal content for iron

60 x crustal content for copper, lead, zinc, and tin

Only several parts per million for gold and

platinum

HOW ARE MINERALS

FORMED?

Mineral Formation Processes

Sedimentation (coal)

Precipitation (salts, metals)

Crystallization from Magma Plutons (ores)

Changes in Temperature and Pressure (ores)

Fluid Inclusions (ores)

Sedimentation of Coal

Crystallization from Magma Plumbs

Fluid Inclusions

Mineral Groups

Silicates Contain

Silicon

Oxygen

Quartz (SiO2)

Carbonates Contain

Carbon

Oxygen

One or More Metallic

Elements

Dolomite

Oxides Contain

Oxygen

One or More Other

Elements (Usually

Metals)

Iron Oxide

Sulfates and Sulfides Contain

Sulfur

One or More Other

Elements

Iron Sulfide - Pyrite

Halides Contain

Halogen Ion

chlorine, fluorine,

bromide and iodine

One or More Other

Elements

Fluorite

WHAT ARE THE PROPERTIES

OF MINERALS AND HOW ARE

THEY IDENTIFIED?

Mineral Identification

Crystalline Structure

Hardness

Luster

Color

Streak

Cleavage

Fracture

Specific Gravity

Fluorescence

Magnetism

Tenacity

Radioactivity

Piezoelectricity

Reactivity to Dilute

Acids

Color

Imperial Topaz - Al2F2SiO4

Streak

Hematite is Fe3O4

Luster

Minerals are Crystalline

Fig. 3-8, p. 78

Most minerals atoms are arranged in regular,

3D frameworks

Typical of Halite Typical of Pyrite Typical of

Diamonds

Typical of

Quartz

Cleavage Patterns

Fig. 3-17, p. 88

Mineral Databasehttp://webmineral.com/

WHAT ARE NONRENEWABLE

MINERAL RESOURCES?

Metallic Mineral Resources

Iron

Tin

Copper

Aluminum

Gold

Platinum (PGE’s)

Tin Mine, Bolivia

Non-Metallic Mineral Resources

Salt

Clay

Sand

Phosphates

Soil

Phosphate Mine,

Florida

Energy Resources

Coal

Oil

Natural Gas

Uranium

The Rössing Uranium Mine; located in the Namib

Desert, Erongo Region, Namibia.

HOW ARE BURIED MINERAL

DEPOSITS FOUND?

Underground Detective Work

Aerial Photos

Satellite Image

Radiation-Measuring Equipment

Magnetometer

Gravimeter

InfoTerra - Satelliteshttp://www.infoterra.co.uk/applications_ogm_mineral.php

Example Mineral Analysis

Mineral Resource GIS Databasehttp://gdr.nrcan.gc.ca/minres/data_e.php

Magnetometer Survey

Measures changes in the

Earth’s magnetic field

caused by magnetic

minerals, such as iron ore.

Deep-Ocean Gravimeter

Measures differences in

gravity caused by

differences in density

between an ore deposit

and the surrounding rock.

HOW ARE BURIED MINERAL

DEPOSITS REMOVED?

Mining Strategies

Surface Mining

Sub-Surface Mining

Surface Mining Methods

Open-Pit Mining

Glory-Hole Mining

Dredging

Area Strip Mining

Contour Strip Mining

Mountaintop Removal

Appalachian Mountain Top Removal of Coalhttp://www.appvoices.org/index.php?/site/mtr_overview/

Mineral Deposits Associated with

Magma Intrusions

Located in Siberia,

the mine in the

picture is apparently

the world's largest

diamond mine.

Kimberlites

Mineral Deposits Associated with Plate

Boundaries

Fig. 2-26, p. 62

Escondida Copper Mine, Chili

is today the world's largest producing mine with 750,000 metric tons of production which was 5.6% of the world's production in 2000.

Sub-Surface Mining Methods

Digging Deep Vertical Shafts

Blast Subsurface Tunnels

Use Machinery to Remove Ore

WHAT ARE THE ENVIRONMENTAL

IMPACTS OF USING MINERAL

RESOURCES?

Impacts (mining, processing, use)

Scarring and disruption of land surface

Collapse of land above mines

Wind or water erosion of toxic mineral wastes

Thermal water pollution

Acid mine drainage

Emission of toxic chemical into atmosphere

Noise Pollution

Nickel Tailings in a River