PLATE TECTONICSROCKY CYCLE, MINERALS, VOLCANOES, & EARTHQUAKESIntegrated Science

Minerals can be identified by their properties

A mineral is a naturally occurring, solid substance made up of a single element or compound.

Examples Halite (table salt), copper, gold, and silver.

All minerals are inorganic—they are never formed by living or once living things.

Minerals have crystalline structures that reflect the orderly arrangement of their atoms.

Minerals can be identified by their properties

Geologists classify minerals into different groups. The classification is based upon their chemical

composition (which elements are present) and their crystalline structure (how the elements are arranged).

It is often easy to identify and classify minerals by observing their physical properties, (crystal form, hardness, cleavage, luster, color, streak, and specific gravity).

Minerals can be identified by their properties

Crystal Form The orderly arrangement of atoms in a crystal Fool’s gold (iron pyrite) you can see the cubes,

quartz has 6 sided prisms that end in a point, asbestos is in threadlike fibers, hematite has globular shapes that looks like grapes

Well shaped crystals are rare in nature because the crystals must grow in cramped spaces.

Minerals can be identified by their properties

IRON PYRITE HEMATITE

Minerals can be identified by their properties

Sometimes two or more minerals come from the same elements in the same proportions but they are arranged differently, these are called polymorphs.

Graphite and Diamond are polymorphs made of carbon, because of the different arrangement both have vastly different properties.

The formation depends upon the particular temperatures and pressures, this makes them good indictors of the geologic conditions at their formation sites.

Minerals can be identified by their properties

Minerals can be identified by their properties

Hardness is the Resistance of a Mineral to Scratching Diamonds can scratch glass because it is harder than

the glass. The harder mineral will always scratch the softer one. Hardness depends on the strength of a minerals’

chemical bonds—the stronger the bonds the harder the mineral

Minerals can be identified by their properties

Factors that influence bond strength are ionic charge, atom or ion size, and packing.

Strong bonds generally occur between charge ions (ionic bonding) the greater the attraction the stronger the bond.

Size affects strength because small atoms and ions can generally pack closer together than large atoms and ions.

Closely packed atoms and ions have a smaller distance between them and are attracted to each other with more force.

Gold with large atoms is soft, while diamond with small carbon atoms is hard.

Minerals can be identified by their properties

Cleavage and Fracture are ways in which minerals break Cleavage is the property of a mineral to break along

planes of weakness (determined by crystal structure and chemical bond strength)

Muscovite (mica) has perfect cleavage in one direction, it will break into thin sheets

Calcite has cleavage in 3 directions, it breaks to form rhombohedral faces.

Garnet has no cleavage (strong bonds in all directions)

Mica Calcite

Minerals can be identified by their properties

Fracture is when a mineral breaks but not along a cleavage plane.

A fracture that is smooth and curved so that it resembles broken glass is called conchoidal.

Most minerals fracture irregularly.

Minerals can be identified by their properties

Luster of a mineral is the way its surface when it reflects light

Minerals of the same color may have different lusters, and minerals of the same luster may different colors.

Adamantine - very gemmy crystalsDull - just a non-reflective surface of any kind Earthy - the look of dirt or dried mudFibrous - the look of fibers Greasy - the look of grease Gumdrop - the look a sucked on hard candy Metallic - the look of metals Pearly - the look of a pearl Pitchy - the look of tar Resinous - the look of resins such as dried glue or chewing gum Silky - the look of silk, similar to fibrous but more compact Submetallic - a poor metallic luster, opaque but reflecting little light Vitreous - the most common luster, it simply means the look of glass Waxy - the look of wax

MINERAL LUSTERS

Minerals can be identified by their properties

A minerals color is easily observable feature, it is not very reliable means of identification.

Some minerals such as copper and turquoise have a distinct color.

The majority of minerals can be occur in a variety of colors or can be colorless.

Chemical impurities can affect a mineral’s color The mineral corundum gives us red rubies or blue

sapphires depending upon the impurities in it.

Minerals can be identified by their properties

Streak is the name given to the color of a mineral in its powdered form.

This is a very important characteristic of identifying minerals have a metallic or semimetallic luster.

The streak test- when rubbed across an unglazed porcelain plate, all minerals leave behind a thin layer of powder—a streak.

The streak of a mineral is always the same color, no matter the color variance of the mineral

A white streak (nonmetallic luster)cannot be used to identify minerals.

Minerals can be identified by their properties

Specific Gravity Density = Mass / Volume (how heavy a

mineral feels for its size) Specific Gravity = Density of mineral /

Density of Water Gold has specific gravity of 19.3 This

allows miners to pan for gold.

Minerals can be identified by their properties

Chemical Properties Two simple tests are the taste test and the

acid test (fizz test—Carbon dioxide CO2) The taste test is used to identify halite

(common table salt) Do not taste test minerals some are poisonous!!

Carbonate minerals will fizz when dilute (low concentrations) of hydrochloric acid (HCl) are place on them

On the way to Rocks Rocks are made of many different minerals Minerals are formed from the process of

crystallization (growth of a material whose atoms come together in a specific chemical composition and crystalline arrangements)

Crystallization of minerals comes from 2 different sources magma (igneous rock) and water solutions (sedimentary rock)

On the way to Rocks Melting point and Freezing point are the

same temp! Minerals melt at about 750oC to 1000oC The Earth’s temp increases about 30oC

for every km. When minerals & rock melt new magma

is produced, when magma cools minerals form and new rock is produced.

On the way to Rocks Partial melting occurs because rocks are made of

many minerals. The lower melting point minerals melt first.

If the whole rock melts the magma has the same chemical composition as the original rock.

Because of the different minerals that end up in the magma it then will cool into different rock types.

On the way to Rocks Crystallization also occurs in water solutions. Chemical sediments are formed when minerals precipitate form

water in they were dissolved. There are 2 categories: carbonates and evaporites Limestone is the most abundant carbonate rock, it forms when

organisms with shells die they accumulate at the bottom of the sea floor, through compaction over time limestone forms.

Cave dripstones (stalactites & stalagmites) also form from precipitating sediment from dripping water

Evaporites are formed when a restricted body of salty lake water evaporates. Gypsum and halite are form this way.

Rocks are divided into 3 Main Groups Many rocks are either created, changed, or

destroyed at plate boundaries. Igneous rock formed by the cooling and

crystallization of hot molten rock called magma. (Igneous means formed by fire)

Igneous rock makes up 95% of the Earth’s crust, Basalt and Granite are common igneous rocks.

Rocks are divided into 3 Main Groups Sedimentary rocksare formed from pieces of

other rocks (sediments) carried by water, wind, or ice. Sedimentary rocks are the most common rocks in the uppermost part of the Earth’s crust.

In fact sedimentary rocks cover more than 2/3 of the Earth’s surface, Sandstone, shale and limestone are common sedimentary rocks

Rocks are divided into 3 Main Groups Metamorphic rockare formed from older pre-

existing rocks (igneous, sedimentary, or metamorphic) that are transformed by high temperature, high pressure, or both WITHOUT melting.

The word metamorphic means “changed in form” Marble and slate are common metamorphic rocks.

Rocks are divided into 3 Main Groups Igneous rock forms when magma cools

Most of the continents are made of granite Basalt is the most common on ocean floors

Extrusive (means pushed out of)igneous rock forms at the surface of the Earth

Partial melting and crystallization produce a variety of magma types (different amounts of silicon they contain)

The higher the silicon content the magma flows more slowly. Temperature also affects the ability to flow of magma

Rocks are divided into 3 Main Groups Magma on the surface is called lava Lava can come from cracks and fractures

in the Earth’s surface or volcanoes. Most fissure eruptions occur when fast-

flowing basaltic lava erupts at the bottom of the ocean forming the ocean floor.

Volcanoes come in a Variety of Shapes and sizes All volcanoes are basically vents or holes where magma

can rise to the Earth’s surface Shield volcanoes have gently sloping cones that resemble

a shield They are built from many lava flows that pour out in all

directions to cool as thin, gently sloping sheets Some of the largest volcanoes in the world are shield

volcanoes Mauna Loa in Hawaii stands 4145 meters (13,599 ft) above sea level

and more than 6750 meters (22,146 ft) above the deep ocean floor

Volcanoes come in a Variety of Shapes and sizes Cinder cones

Earthquakes Make Seismic Wave

All earthquakes create waves that travel through the Earth’s interior.

Earthquake generated waves are called seismic waves. The way these waves travel provides scientists with a view into the Earth’s interior.

The major layers of the Earth the crust, mantle, outer core, and inner core.

A wave’s speed depends on the medium through which it travels. Example Sound waves travels faster through water than through air.

Earthquakes Make Seismic Wave

The speed of seismic waves depends upon the elasticity of the material through which they are traveling

Energy is released in an earthquake and radiates in all directions. This energy travels to the surface in the form of seismic waves.

Seismic waves cause the ground to shake and move. This movement is recorded on a machine called a seismograph.

2 Types of Seismic Waves

Body Waves

Primary Waves

(P Waves)

Like Sound Waves are Longitudinal—they compress and expand the rock they move

thruThey move out in all directions

Fastest seismic wavesTravel thru any material

Secondary Waves

(S Waves)

Transverse Wave, they vibrate particles up & down

and side to sideSlower than P waves

Cannot pass thru fluids

Surface Waves

Rayleigh Waves

Move in an Up and Down Motion

Move slower than P & S Waves

Love Waves

Move in a side to side motion

Move slower than P & S Waves

Animations for Plate tectonics http://education.sdsc.edu/optiputer/teachers/oceanfloordyn

amics.html

Types of PlateBoundaries & Landforms

Sedimentary Rocks• 2 kinds of weathering produce sediment• Mechanical weathering physically breaks rocks into

sediments• Chemical weathering consists of chemical reactions that

involve water and decompose rock into smaller pieces.• As rock is weathered it erodes (which means it is

transported by water, wind, or ice)

Sedimentary Rocks• Clastic sediment is small fragments of other rocks (are

usually very jagged until they are transported and break when they collide with other rocks or fragments)

• Chemical sediment is produced by chemical means• Glaciers usually deposit poorly sorted sediments while

wind is usually very well sorted and fine grained.

Sedimentary Rocks• In sedimentation, sediment particles are

deposited one layer at a time it then becomes rock thru compaction and cementation

• Minerals dissolved in water is what acts as the cement that bonds the sediments together

• Iron oxide will produce red or orange rocks

• Limestone is formed by the precipitation of calcium carbonate

http://www.uwgb.edu/dutchs/PLANETS/earth.htm

Overview of Earth Systems The three main components of the Earth

are the atmosphere, its gaseous envelope, the hydrosphere, the surface coating of water, and of course, the solid earth. All three are subdivided into subsystems. The atmosphere and hydrosphere get their energy mostly from the Sun, and the solid earth gets its energy from internal heat, some of which is produced by radioactive decay and some is left over from the formation of the earth. A tiny amount of energy also comes from gravitational interactions between the Earth, the Moon, and the Sun.

Convection is the transportation of heat by moving hot or cold material from place to place. Convection works because warm material is light and rises, while cool material is denser and sinks. As long as there is a temperature difference with depth, there will be a cycle of rising and sinking material. A lava lamp is a perfect illustration of convection - if geophysicists, astronomers, and other scientists who teach about convection had their way, lava lamps would never go out of style.

In reality, there is a continuous cycle. Material at the base of the mantle becomes hot and rises. As it rises, it expands and cools, and near the surface, heat leaks through the crust and escapes. Cooled mantle material begins sinking and descends to the bottom of the mantle, to be heated again.