Rock Cycles Minerals

7/29/2019 Rock Cycles Minerals

1/36

Rock Cycles, Rocks, Minerals,

& Resources

Education 370

Joseph Lombardi


2/36

The Rock Cycle


3/36

The Rock Cycle

Crystallization- Molten magma cools, and

solidifies within the Earth to produce igneous

rocks. Crystallization may occur either beneath the

surface or, following a volcanic eruption, at the

surface.

If the igneous rocks are exposed at the surface,

they will undergo a process termed weathering.


4/36

The Rock Cycle Continued

Weathering is defined as the disintegration and

decomposition of igneous rock at or near the

surface of the Earth. The materials, or sediment that result are moved

down-slope by gravity before being picked up and

transported by any of a number of erosional

agents- running water, glaciers, wind, or waves.


5/36


Eventually these particles and dissolved

substances are deposited in the ocean, river

floodplains, desert basins, swamps, and dunes. Next, the sediments undergo lithification, a term

meaning conversion into rock.

Sediment is usually lithified into sedimentary rock

when compacted by the weight of overlying layers

or when cemented as percolating groundwater fills

the pores with mineral matter.


6/36


If the resulting sedimentary rock is buried deep within the

Earth and involved in the dynamics of mountain building,

or intruded by a mass of magma, it will be subjected to

great pressures and/or intense heat.

The sedimentary rock will react to the changing

environment and turn into metamorphic rock.

When metamorphic rock is subjected to additional pressure

changes or to still higher temperatures, it will melt,

creating magma, which will eventually crystallize into

igneous rock.


7/36

Summary: The Rock Cycle

Processes driven by heat from the Earths interiorare responsible for creating igneous andmetamorphic rocks.

Weathering and erosion, external processespowered by energy from the sun, produce thesediment from which sedimentary rocks form.

Although rocks may seem to be unchangingmasses, the rock cycle shows that they are not.The changes, however, take time-great amounts oftime.


8/36

The Rock Cycle: Alternative

Pathways Igneous rocks, rather than being exposed to

weathering and erosion at the Earths surface may

remain deeply buried. Eventually these masses may be subjected to the

strong compressional forces and high temperatures

associated with mountain building.

When this occurs, the igneous rocks are

transformed directly into metamorphic rocks.


9/36

The Rock Cycle: Alternative

Pathways Continued Metamorphic and sedimentary rocks, as

well as sediment, do not always remain

buried. Rather, overlying layers may be stripped

away, exposing the once buried rock.

When this happens the material is attackedby weathering processes and turned intonew raw materials for sedimentary rocks.


10/36

The Rock Cycle


11/36

Earth Materials & Processes

The materials that make up the Earth are

mainly rocks (including soil, sand, silt, and

dust).

Rocks in turn are composed of minerals,

and minerals are composed of atoms.

Processes range from those that occurrapidly to those that occur slowly.


12/36


Continued Examples of slow processes include:

formation of rocks, chemical breakdown of

rock to form soil (weathering), chemicalcementation of sand grains together to form

rocks (diagenesis), re-crystallization of rock

to form a different rock (metamorphism),construction of mountain ranges

(tectonism), erosion of mountain ranges.


13/36


Continued Examples of faster processes include: beach

erosion during a storm, construction of a

volcanic cone, landslides (avalanches), duststorms, mud flows.


14/36

Types Of Rocks


15/36

Types Of Rocks Continued

Igneous Sedimentary, &

Metamorphic Rocks

Igneous rock is formed by the crystallization of

molten magma. Sedimentary rock is formed from the weathered

products of free-existing rocks that have beentransported, deposited, and lithified.

Metamorphic rock is formed by the alteration ofpre-existing rock deep within the Earth (but still insolid state) by heat, pressure, and/or chemicallyactive fluids.


16/36

Characteristics of Minerals

Minerals are defined as naturally occurring,

inorganic crystalline solids that possess a

definite chemical structure.

Minerals are the building blocks of rocks.


17/36

Properties of Minerals

Crystal form: The external appearance of a

mineral as determined by its internal

arrangement of atoms. Luster: Luster is the appearance or quality

of light reflected from the surface of a

mineral. Color.


18/36

Properties of Minerals

Continued Streak: The color of a mineral in its

powdered form.

Hardness: The resistance a mineral offers toscratching.

Cleavage: The tendency of a mineral to

break along planes of weak bonding.


19/36

Mohs Scale of Mineral

Hardness


20/36

Mineral Groups

Minerals can be classified into groups

depending upon their chemical composition.


21/36

Relative Abundance Of The

Most Common Elements In

The Earths Crust Oxygen (O) 46.6%, Silicon (Si) 27.7%,

Aluminum (Al) 8.1%, Iron (Fe) 5.0%, Calcium

(Ca) 3.6%, Sodium (Na) 2.8%, Potassium (K)2.6%, Magnesium (Mg) 2.1%, All others 1.7%.


22/36

Mineral Groups Continued The largest group of rock forming minerals is the

silicate group.

All silicate minerals contain silicon and oxygen.

Some examples of silicate minerals are olivine,augite hornblende, garnet, biotite, albite, andquartz.

Silicates are the most common minerals because

most of the Earths crust is made of silicon andoxygen.


23/36

Mineral Groups Continued

Non-silicate minerals are those that do not

contain silicon and oxygen.

There are five groups of non-silicates:oxides, sulfides, halides, carbonates and

sulfates.


24/36


Oxides Oxides are minerals that form when an

element combines with oxygen.

Some examples of oxides are corundum,hematite, and magnetite.


25/36


Sulfides Sulfides are minerals that form from

compounds that contain sulfur.

Some examples of sulfides are galena andpyrite.


26/36


Halides Halides are minerals that form when certainelements combine with the Halogen Group

from the periodic table.

The halogen group includes chlorine,

bromine, fluorine, and iodine.

Some examples of halides are halite and

fluorite.


27/36


Carbonates Carbonates are minerals that contain a

carbon atom surrounded by three oxygen

atoms (carbonate ion). Some minerals that contain this ion are

azurite, aragonite, and malachite.


28/36


Sulfates Sulfates are minerals that contain a sulfur

atom surrounded by four oxygen atoms

(sulfate ion). Some minerals that contain this ion are

gypsum, celestite, and barite.


29/36

Mineral Resources

Mineral resources are the Earths storehouse of

useful minerals that can be recovered for use.

Resources include already identified deposits fromwhich minerals can be extracted profitably, called

reserves, as well as well known deposits that are

not yet recoverable under present economic

conditions or technology.

Deposits inferred to exist, but not yet discovered,

are also considered as mineral resources.


30/36

Mineral Resources Continued

There three principal categories for mineral uses

are: rock forming, economic, gems and

ornamentals. Rock forming refers to the primary function or use

of some minerals.

Many minerals have commercial or economic use.

Some minerals are considered ore minerals (e.g.

hematiteiron ore), while others are common

commercial products (e.g. calcitecement).


31/36


Common gemstones used in jewelry are

actually minerals. Examples are diamonds,

garnet, and amethyst. Large mineral specimens can also be used

for decorative or ornamental purposes.

Examples are pyrite (fools gold), or geodeslined with quartz or amethyst crystals.


32/36


Recall that more than 98% of the Earths

crust is composed of only eight elements.

Except for oxygen and silicon, all otherelements make up a relatively small fraction

of common crustal rocks. Indeed, the

natural concentrations of many elements areexceedingly small.


33/36


A deposit containing only the average

crustal percentage of a valuable element

like gold is worthless if the cost ofextracting it greatly exceeds the value of the

material recovered.

To be considered of value, an element mustbe concentrated above the level of its

average crustal abundance.


34/36


Examples of minerals and their economic

use: Hematite (oxides) ore of iron, Galena

(sulfides) ore of lead, Gypsum (sulfates)plaster, Gold (native elements) trade and

jewelry, Fluorite (halides) used in steel

making, and Calcite (carbonates) Portlandcement and lime.


35/36

Works Cited

1.) The Mineral Gallery

http://minerals.galleries.com/default.html

2.) Minerals

http://www.tulane.edu/~sanelson/geol111/m

inerals.html

3.) Rock Cycle Images

http://rst.gsfc.nasa.gov/Sect2/Sect2_1a.html
http://minerals.galleries.com/default.htmlhttp://www.tulane.edu/~sanelson/geol111/minerals.htmlhttp://www.tulane.edu/~sanelson/geol111/minerals.htmlhttp://rst.gsfc.nasa.gov/Sect2/Sect2_1a.htmlhttp://rst.gsfc.nasa.gov/Sect2/Sect2_1a.htmlhttp://www.tulane.edu/~sanelson/geol111/minerals.htmlhttp://www.tulane.edu/~sanelson/geol111/minerals.htmlhttp://minerals.galleries.com/default.html


36/36

Works Cited Continued

4.) Tarbuck, Edward J., Lutgens, Frederick

K. Earth Science 8th Ed. 1997 New Jersey:

Prentice Hall Inc. 5.) Image- silicon-oxygen tetrahedron

http://www.msdwc.k12.in.us/msdclass/WE

NJ
http://www.msdwc.k12.in.us/msdclass/WENJhttp://www.msdwc.k12.in.us/msdclass/WENJhttp://www.msdwc.k12.in.us/msdclass/WENJhttp://www.msdwc.k12.in.us/msdclass/WENJ

Rock Cycles Minerals

Documents