You Rock My WorldYou Rock My WorldIntroduction to Rocks and Introduction to Rocks and

LandformsLandforms

Mdm Masayu MahmudMdm Masayu Mahmud

Department of HumanitiesDepartment of Humanities

Innova Junior College, Innova Junior College, SingaporeSingapore

Who Wants to own my Who Wants to own my Oreos?Oreos?

For one Oreos…. For one Oreos….

What rock can float on water?What rock can float on water?

A)A) AeroliteAerolite

B)B) PumicePumice

C)C) ChalkChalk

D)D) EolianiteEolianite

And the Answer Is……And the Answer Is…… Pumice is a type of lava full of gas Pumice is a type of lava full of gas

bubbles. It can be as light as bubbles. It can be as light as Styrofoam, or nearly as dense as Styrofoam, or nearly as dense as normal rock. normal rock.

Aerolite is an old name for meteorites, Aerolite is an old name for meteorites, and Eolianite is any rock type that is and Eolianite is any rock type that is made of windblown sediment. Chalk is made of windblown sediment. Chalk is a lightweight rock, but not a lightweight rock, but not thatthat light. light.

So what exactly is a So what exactly is a rock?rock?

A rock is a naturally occurring A rock is a naturally occurring mass of inorganic or organic mass of inorganic or organic material that forms a significant material that forms a significant part of the earth's crust.part of the earth's crust.

A A rockrock can also be defined as a can also be defined as a solid substance that occurs solid substance that occurs naturally because of the effects naturally because of the effects of three basic geological of three basic geological processes: processes: magmamagma solidification; solidification; sedimentationsedimentation of of weatheredweathered rock debris; and rock debris; and metamorphismmetamorphism..

http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Slideshow/Igrocks/Igrock13.html

A Rock by Any Other A Rock by Any Other Name….Name….

From the physical properties of rock, earth scientists can determine:

The general type of environment in which the rock formed (volcanic, tropical marine, arid terrestrial, etc.)

The general water depth (if marine or fresh water)

The relative age of the rock (using fossils) or possibly its absolute age (if radioactive minerals are present)

Its original position and orientation on the surface of earth

http://geollab.jmu.edu/Fichter/IgnRx/Introigrx.html

Rock Type and Rock Type and ClassificationClassification

3 types of rocks3 types of rocksIgneous rocksIgneous rocks - produced by solidification - produced by solidification of molten magma from the mantle. of molten magma from the mantle. Sedimentary rocksSedimentary rocks - formed by burial, - formed by burial, compression, and chemical modification of compression, and chemical modification of deposited weathered rock debris or deposited weathered rock debris or sediments at the earth's surface.sediments at the earth's surface.Metamorphic rocksMetamorphic rocks - created when existing - created when existing rock is chemically or physically modified rock is chemically or physically modified by intense heat or pressure.by intense heat or pressure.

Igneous RockIgneous Rock

Rocks formed by crystallization from a melt Rocks formed by crystallization from a melt (magma)(magma)

1.1. Extrusive (volcanic) - produced when magma Extrusive (volcanic) - produced when magma flows on the earth's surface flows on the earth's surface

2.2. Intrusive (plutonic) - produced when magma Intrusive (plutonic) - produced when magma solidifies at depth beneath the earthsolidifies at depth beneath the earth

Rate of cooling & temperature changes Rate of cooling & temperature changes determine the texture & degree of determine the texture & degree of crystallization while the composition of the crystallization while the composition of the magma will determine the composition of the magma will determine the composition of the igneous rockigneous rockhttp://geollab.jmu.edu/Fichter/IgnRx/Introigrx.html

Formation of igneous Formation of igneous rocksrocks

http://sln.fi.edu/fellows/fellow1/oct98/create/igneous.htm

http://www.geocities.com/RainForest/Canopy/1080/igneous_formation.htm

Classification of Classification of Igneous RockIgneous Rock

Process-oriented. Based on the rate of cooling of the igneous Process-oriented. Based on the rate of cooling of the igneous rocks rocks

And their resultant grain size. And their resultant grain size. Texture - size, shape and arrangement of mineral grains in Texture - size, shape and arrangement of mineral grains in

a rock.a rock. Coarse grained - individual mineral grains can be seen Coarse grained - individual mineral grains can be seen

which the naked eye. Rock must have cooled slowly to which the naked eye. Rock must have cooled slowly to allow large crystals to develop.allow large crystals to develop.

Fine grained - mineral grains are present but are two small Fine grained - mineral grains are present but are two small to be seem with the eye. Cooled rapidly before crystals had to be seem with the eye. Cooled rapidly before crystals had a chance to grow.a chance to grow.

Vesicular - rock containing vesicles (gas holes). Always Vesicular - rock containing vesicles (gas holes). Always light weight. Example pumice.light weight. Example pumice.

Glassy - not composed of minerals at all but a true glass. Glassy - not composed of minerals at all but a true glass. Glasses are Glasses are notnot crystalline! crystalline!

Examples of Igneous Examples of Igneous RocksRocks

Granite

1. Light color2. Low specific gravity

3. Coarse grained

4. Forms on the continents deep underground

Basalt

1. Dark color2. High specific gravity3. Fine grained

4. Forms at the surface, principally in the ocean basins, but also in isolated "hot spots" on the continents.

Pictorial Classification of Igneous Pictorial Classification of Igneous RocksRocks

http://geollab.jmu.edu/Fichter/IgnRx/Introigrx.html

Think!!!!!Think!!!!!

Why do we Why do we see intrusive see intrusive igneous rocks igneous rocks at the surface at the surface of the earth? of the earth? 

Sedimentary RocksSedimentary Rocks Layered or stratified rocks Layered or stratified rocks

formed at or near the earth's formed at or near the earth's surface in response to the surface in response to the processes of weathering, processes of weathering, erosion, transportation and erosion, transportation and deposition.deposition.

Sedimentary rocks are generally Sedimentary rocks are generally stratified, fine-grained or stratified, fine-grained or composed of fragments of older composed of fragments of older rocks from which these were rocks from which these were derived, such as pebbles, sand, derived, such as pebbles, sand, angular fragments of older angular fragments of older rocks, broken shells, rounded rocks, broken shells, rounded mineral grains and alteration mineral grains and alteration minerals such as clays. minerals such as clays.

Formation of Formation of Sedimentary RocksSedimentary Rocks

Sediment = loose particulate material (clay, sand, gravel, etc.) Sediment becomes sedimentary rock through lithification, which involves:

1.Compaction 2.Cementation 3.Recrystallization (of carbonate sediment)

Types of Sedimentary Types of Sedimentary RockRock

Mechanically–formed rocks : formed by Mechanically–formed rocks : formed by compression & cementation of sediments compression & cementation of sediments deposited over a long periods in the sea e.g: deposited over a long periods in the sea e.g: shale, sandstone, conglomerateshale, sandstone, conglomerate

Organically-formed rocks : formed by Organically-formed rocks : formed by compression & cementation of plants & animal compression & cementation of plants & animal remains e.g : coal ( from decayed plants), remains e.g : coal ( from decayed plants), limestone & chalk (from shells of sea animals)limestone & chalk (from shells of sea animals)

Chemically-formed rocks : formed when water Chemically-formed rocks : formed when water has evaporated from solutions which contain has evaporated from solutions which contain minerals e.g : rock saltminerals e.g : rock salt

Characteristics of Characteristics of Sedimentary RocksSedimentary Rocks

May stratified because the May stratified because the sediments are laid down in sediments are laid down in horizontal layers called horizontal layers called strata. ( one layer is strata. ( one layer is called stratum)called stratum)

May also contain fossil i.e: May also contain fossil i.e: remains, prints or other remains, prints or other indications of plants & indications of plants & animals found buried in animals found buried in rocksrocks

Dipping sedimentary layers of rock, Rocky Mountains, Canada.

http://www.geog.ouc.bc.ca/physgeog/contents/10f.html

Examples of Sedimentary Features Examples of Sedimentary Features and Landformsand Landforms

The Queen’s Throne- Utahhttp://www.uh.edu/~jbutler/physical/chapter7.html

Narracoorte Caves, southeastern SA

Stalactites (of mineral calcite). Biochemical and inorganic sedimentary limestone rocks.

A Rock With a ViewA Rock With a View The The sandstonesandstone was was

formed from sandy river formed from sandy river deposits, a relatively high deposits, a relatively high energy environment. energy environment.

After consolidation into After consolidation into rock these beds were rock these beds were gently uplifted, remaining gently uplifted, remaining almost horizontal. almost horizontal.

Cliff reveals layers which Cliff reveals layers which vary slightly in hardness vary slightly in hardness and reflect variations in and reflect variations in original conditionsoriginal conditionsHeadland in Tasman Peninsula

World’s Biggest RockWorld’s Biggest Rock The Ayers Rock is The Ayers Rock is

made up of arkose, a made up of arkose, a course-grained course-grained sandstone rich in sandstone rich in feldspar at least 2.5 km feldspar at least 2.5 km thick. Uplifting and thick. Uplifting and folding between 400-folding between 400-300 mya turned the 300 mya turned the sedimentary layers sedimentary layers nearly 90 degrees to nearly 90 degrees to their present position. their present position. The surface has then The surface has then been eroded. been eroded.

Metamorphic RocksMetamorphic Rocks

The word The word ""MetamorphismMetamorphism" comes " comes from the Greek:  Meta = from the Greek:  Meta = change, Morph = form, so change, Morph = form, so metamorphism means to metamorphism means to change form.  change form. 

In geology this refers to In geology this refers to the changes in mineral the changes in mineral assemblage and texture assemblage and texture that result from subjecting that result from subjecting a rock to pressures and a rock to pressures and temperatures different temperatures different from those under which from those under which the rock originally formed. the rock originally formed.

Formation of Formation of Metamorphic RocksMetamorphic Rocks

MetamorphismMetamorphism is is the solid-state the solid-state transformation of pre-transformation of pre-existing rock into existing rock into texturally or texturally or mineralogically mineralogically distinct new rock as distinct new rock as the result of high the result of high temperature high temperature high pressure, or both. pressure, or both. http://sln.fi.edu/fellows/fellow1/oct98/create/metamorph.htm

Types of Types of MetamorphismMetamorphism

Regional metamorphism : takes place during Regional metamorphism : takes place during mountain building when rocks are mountain building when rocks are metamorphosedmetamorphosed

Contact metamorphism found in the vicinity of Contact metamorphism found in the vicinity of igneous intrusions & the high temperatures of igneous intrusions & the high temperatures of magma heats the rock adjacent to these magma heats the rock adjacent to these intrusions, causing recrystallization & growth of intrusions, causing recrystallization & growth of crystalscrystals

Pressure metamorphism : rocks are altered under Pressure metamorphism : rocks are altered under high pressure associated with Earth movements high pressure associated with Earth movements (folding & faulting)(folding & faulting)

Examples of Metamorphic Examples of Metamorphic RocksRocks

Slate is a fine grained metamorphic rock. Created by minor metamorphism of shale or mudstone. Rock is characterized by the foliation of its mineral grains which causes it to have cleavage that is parallel.

Gneiss is a coarse grained metamorphized igneous rock. In this rock, you get the recrystallization and

foliation of quartz, feldspars, micas, and amphiboles into alternating light and

dark colored bands.

Characteristics of Characteristics of Metamorphic RocksMetamorphic Rocks

Harder and more compact than the rock they are made from. Harder and more compact than the rock they are made from. Minerals are arranged in bands or recrystallised to form new Minerals are arranged in bands or recrystallised to form new

or larger mineralsor larger minerals

SchistMarble

Foliated vs. Non-Foliated vs. Non-Foliated?Foliated?

The minerals grains in rocks subjected to extreme pressure often rearrange themselves in a parallel fashion, creating a foliated texture (Image A - before metamorphism; Image B - after metamorphism).

Do Rocks Do Rocks Always Always Stay the Stay the Same?Same?

Concept of Rock CycleConcept of Rock Cycle

Authored by James Hutton (1727–Authored by James Hutton (1727–1797), the eminent 18th century 1797), the eminent 18th century gentleman farmer and founder of gentleman farmer and founder of modern geoscience which depicts modern geoscience which depicts the interrelationships between the interrelationships between igneous, sedimentary, and igneous, sedimentary, and metamorphic rocks.metamorphic rocks.

Upper part of the earth envisioned Upper part of the earth envisioned as a giant recycling machine; matter as a giant recycling machine; matter that makes up rocks is neither that makes up rocks is neither created nor destroyed, but is created nor destroyed, but is redistributed and transformed from redistributed and transformed from one rock type to another. one rock type to another.

James Huttonhttp://www.gennet.org/facts/hutton.html

Diagrammatic Representation Diagrammatic Representation of Rock Cycleof Rock Cycle

http://www.science.ubc.ca/~geol202/rock_cycle/rockcycle.html

How does it work??How does it work??• Most surface rocks started out as igneous rocks- rocks produced by crystallization from a liquid. • When igneous rocks are exposed at the surface they are subject to weathering (chemical and mechanical processes that reduce rocks to particles). • Erosion moves particles into rivers and oceans where they are deposited to become sedimentary rocks. • Sedimentary rocks can be buried or pushed to deeper levels in the Earth, where changes in pressure and temperature cause them to become metamorphic rocks. • At high temperatures metamorphic rocks may melt to become magmas. • Magmas rise to the surface, crystallize to become igneous rocks and the processes starts over.

Rock Cycle SongRock Cycle Song (Sing to the tune of "Row, Row, Row Your Boat")(Sing to the tune of "Row, Row, Row Your Boat")

SEDIMENTARYSEDIMENTARY rock rock Has been formed in layersHas been formed in layers

Often found near water sourcesOften found near water sources With fossils from decayersWith fossils from decayers

Then there's Then there's IGNEOUSIGNEOUS rock rock Here since Earth was bornHere since Earth was born

Molten Lava, cooled and hardenedMolten Lava, cooled and hardened That's how it is formedThat's how it is formed

These two types of rocksThese two types of rocks Can also be transformedCan also be transformed

With pressure, heat and chemicalsWith pressure, heat and chemicals METAMORPHICMETAMORPHIC they'll become. they'll become.

Err..So why am I Err..So why am I learning this?learning this?

• Knowledge of rocks fundamental to study of earth sciences

•Because a rock by any other name is not the same

• Forms the basis for the study of plate tectonics

Geologic Map of Geologic Map of SingaporeSingapore

TaskTask

Research on the properties of Research on the properties of granite, basalt, sandstone, clay and granite, basalt, sandstone, clay and limestone: their chemical limestone: their chemical composition in relation to their composition in relation to their weathering, nature of cementing weathering, nature of cementing material, hardness, texture, jointing, material, hardness, texture, jointing, bedding planesbedding planes