Earth MaterialsMineralsA mineral is a naturally occurring substance with characteristic physical and chemical properties. Nearly all rocks are composed of minerals.Polymineralic rocks are composed of more than one mineral, ex. granite.Monomineralic rocks are composed of only one mineral, ex. limestone.

Earth MaterialsMineral CompositionMinerals are composed of elements. Some minerals contain only one element (copper, sulfur and graphite (carbon)).Most minerals are made up of only a few elements.Oxygen is the most common element by weight and volume.Silicon is second most abundant by weight.

Earth MaterialsProperties of MineralsCharacteristics of minerals include:colorhardnessluster/cahaya/kilauanstreak/garis/corengcleavage/pecah/potongan and fracture/patah/retakdensity

Earth MaterialsProperties of MineralsDifferences in properties are used to categorize and identify minerals.The acid test is the use of hydrochloric acid on limestone. The result is that bubbles of CO2 are liberated/dilepaskan.Minerals have a characteristic crystalline structure, in many cases the silicon-oxygen tetrahedron.

Rock FormationThe Rock Cycle relates the three types of rocks.

Earth MaterialsThe Rock CycleAny one rock type can change into any other rock type.There is no preferred direction of movement of materials in the rock cycle for any one mass of material.There is no exact point of separation between the rock types.

Earth MaterialsThe Rock CycleSedimentary rocks often contain sediments or fragments which have varied origins.The composition of some rocks suggests that the materials (sediments or minerals) in the rock have undergone multiple transformations (changes) within the rock cycle.

Weathering and ErosionWeathering is the breakdown of rocks to form particles called sediment.Physical weathering is the breakdown of rock without chemical changesFreezing and thawing (frost action)Thermal expansion and contractionChemical weathering is the breakdown of rock by chemical actionoxidation, hydration, solution by acids

Weathering and ErosionFactors affecting weathering are:Exposure--more exposure means faster weatheringParticle size--the smaller the particles, the greater the surface areaMineral composition--some minerals (quartz) are more resistant to weathering than others (mica and feldspar)Climate--warmth and moisture enhance weathering

Weathering and ErosionSoilSoil is a product of weathering.Residual soil forms from the weathering of rocks nearby.Transported soil is brought in by erosion.Soil layers develop over time. The soil composition generally tends to reflect the composition of the rocks below.

Weathering and ErosionSoil ProfilesA soil horizon is a vertical layer of soil with certain characteristics. For example, the top layer of soil usually is rich in organic material.Lower horizons result from weathering. The horizon just above the bedrock will contain partially weathered rock.There is a subsoil layer just below the topsoil layer.

Weathering and ErosionSoil typesResidual soil is formed from the rocks below the soil layer. These soils usually relate to the underlying rocks. They can be sandy, clayey or loamy/tanah liat organik if they have much organic material.Transported soil is one that has been move into an area from someplace else by erosion.

Weathering and ErosionErosionErosion is the process by which sediments are obtained and transported.Transporting agents include water (streams), glaciers, waves, density currents in water, wind, and people.Driving forces include gravity and change of potential to kinetic energy.

Weathering and ErosionStream/aliran ErosionStream water carries sediments.Dissolved minerals are carried in solution.Small solid particles are carried in suspension.Large solid particles are moved by rolling or bouncing along on the bottom of the stream.

Weathering and ErosionStream ErosionThe ability to carry sediment depends on velocity. The velocity depends on the gradient (slope) and discharge (volume) of the stream.Stream velocity varies. On a curve, it is fast on the outside and slow on the inside.

Weathering and ErosionStream Erosion

Weathering and ErosionWind ErosionWind causes erosion. When wind carries sediment, it forms dunes/bukit pasir.

Glacial erosionA glacier can carry large amounts of dirt/kotoran.When the glacier stops moving, it drops the dirt forming a moraine/bagian depan sungai es yang bergerak maju.

Weathering and ErosionGlacial ErosionAn example is the Hubbard Glacier in Alaska

Weathering and ErosionGlacial ErosionThere is a moraine in New Jersey left over from the last ice age. The glacier also formed Long Island.

DepositionDeposition is also known as sedimentation.Deposition occurs when the velocity of water, wind or other erosional system decreases. Deposition depends on:Particle size--heavier particles sediment fasterShape--spherical particles sediment fasterDensity--denser particles sediment faster

DepositionRock layers are formed by sediments. The size of the particles determines the rock type.Boulders, gravel, pebbles/batu kerikil--conglomerateSand--sandstoneSilt--siltstoneColloids, clayshale/serpihColloids, chemical sediments--limestone

DepositionDeposition by moving water

DepositionDeposition by moving waterWhen a river enters the ocean, the velocity decreases.Sediments are deposited and form a delta.An example is the Mississippi River Delta.

Rock FormationRocks are the solid material that make up the Earth. There are three types:Sedimentary Rocks--formed by solid sediments weathered from pre-existing rocksIgneous Rocks--formed by cooling of liquid rockMetamorphic Rocks--formed by transformation of igneous or sedimentary rocks by reheating

Rock FormationFormation of sedimentary rocksCementation--larger particles are cemented by minerals precipitated out of the waterCompression--very small particles are compressed by immense weight of water and sediment layers about themChemical action--ionic materials precipitate out of the waterBiological processes--precipitation of minerals by biological organisms

Rock FormationProperties of sedimentary rocksParticles of sedimentary rocks resemble the sediments they came fromSome contain a mixture of sediments, others a single type of sedimentSome sedimentary rocks are of organic origin (example: coal)Sedimentary rocks form layers called strata Sedimentary rocks frequently contain fossils

Sedimentary RocksIdentifying sedimentary rocksThere are three major groups of sedimentary rocks.Detrital rocks form from sediments washed in by water, such as gravel, sand and mud.Chemical sedimentary rocks have crystalline texture: limestone, dolostone, gypsum, saltBiochemical sedimentary rocks: clastic (limestone from shells), chert, coal

Igneous RocksProperties of igneous rocksIgneous rocks are nonsedimentary in originThey form by solidification or crystallization of liquid rock under the Earth called magma Longer cooling time causes big crystals in the rock. Shorter cooling time causes small crystals in the rock.Texture of igneous rock depends on the size of the crystals.

Igneous RocksTypes of igneous rocksIgneous rocks form a gradation between two extremes.Felsic rocks are high in Al and Si.Mafic rocks are high in Mg and Fe.Generally, igneous rocks are identified on the basis of crystal size (texture) and mineral composition

Igneous RocksSequence of cooling of silicate minerals--Bowens Reaction SeriesBowens reaction series accounts for the crystallization of intermediate and felsic magmas from an original basaltic (mafic) magma. It has two branches, continuous and discontinuous.In the continuous branch, calcium-rich plagioclase feldspar crystallizes first followed by sodium-rich plagioclase feldspar.

Igneous RocksSequence of cooling of silicate minerals--Bowens Reaction SeriesIn the discontinuous branch there is a series of one mineral changing to another over time as the melt cools. The sequence is: olivine --> pyroxene --> amphibole --> biotite mica.At this point the two sequences finish with: potassium feldspar (orthoclase) --> muscovite mica --> quartz.

Igneous RocksImportance of texture and compositionThe texture of igneous rocks depends on the size of the crystals as well as their arrangement. Rocks with large crystals cooled slowly. Those with small crystals cooled faster.Mafic rocks are denser and darker than felsic rocks (ex: pyroxene, olivine). Felsic rocks are lighter in color and denser (ex: quartz, felspar, mica)

Metamorphic RocksProperties of metamorphic rocksMetamorphic rocks are also nonsedimentary in origin.Metamorphism is a response to heat and pressure within the Earths crust.Such conditions result from plate collisions, mountain building and sometimes localized heating such as with volcanic eruptions.

Metamorphic RocksProperties of metamorphic rocksMetamorphic rocks form from recrystallization of pre-existing rocks.Metamorphic rocks often show banding where like crystals are arranged in layers.They have a distorted structure caused by curving and folding of the bands.

Metamorphic RocksFoliated vs nonfoliated metamorphic rocksFoliated rocks have crystals arranged in parallel planes. Examples are slate, schist, gneiss.Nonfoliated rocks do not have a preferred orientation among their minerals. Examples are marble, quartzite, greenstone.

Metamorphic RocksSteps leading to the formation of gneissMost gneiss begins with recrystallization of clay-rich sedimentary rocks during regional metamorphism.Gneisses are composed mainly of quartz and/or feldspar, which cause the light bands.The dark bands come from biotite and hornblende.

Metamorphic RocksOrigin and composition of marbleMarble is a metamorphic rock that was originally limestone or dolomite. Limestone marble is made of CaCO3. Dolomite marble is made of CaMg(CO3)2. Limestone marble reacts with the acid test. Dolomitic marble also reacts with the acid test but it must be powered first.

Metamorphic RocksRegional metamorphismRegional metamorphism occurs over a wide area and results from tremendous temperatures, pressures and deformation conditions deep under the surface.It results in a gradation from from low to high metamorphism depending on the levels of temperature and pressure involved.

Civilization and Earth MaterialsHumans use fossil fuels for the major part of their energy needs. These include coal, oil and natural gas.Minerals are used in a variety of human activities.Rocks are quarried and used as building stones and pavement.Earth resources are not renewable. They cannot be restored easily in your lifetime.

Landscape developmentLandscapes are the features of the surface of the Earth.Features include:slope of the landshape of surface featuresstream drainage patternsstream slopesoil characteristics

Landscape developmentMeasuring Landscape CharacteristicsMeasurements can be made using actual observations, maps, aerial photographs or satellite images.Gradients, slopes and profiles are given on topological maps.Major types are mountains, plateaus and plains

Landscape developmentForces that produce landscapesUplift is a raising up of a region of land caused by forces in the crust or by tectonic interaction.Leveling forces break down rocks and transport material on the Earths surface. These include weathering, erosion, deposition, subsidence.

Landscape developmentForces that produce landscapesErosion is the removal of weathered rock materials from their source area.Mass wasting is the downslope movement of rocks, sediments, or soil under the influence of gravity.

Landscape developmentFactors that influence landscape developmentClimate affects the rate of change of a landscape.Glaciers produce U-shaped valleys and deposit soil with a wide range of particle sizes.Streams may not flow all the time in arid climates. Some arid regions have internal drainage where streams deposit water into a basin rather than leading to the ocean. The Great Salt Lake is an example.

Landscape developmentU-shaped valley caused by a glacier

Landscape developmentFactors that influence landscape developmentBedrock greatly influences the landscape above it.Different types of rock have different degrees of resistance to weathering and erosion.Stream drainage patterns indicate information regarding the contour of the bedrock below.

Landscape developmentHuman influence on landscape developmentRemoval of forests for development leads to accelerated erosion of soil when it rains.Acid rain causes increased chemical weathering of rocks. Example: accelerated erosion of limestone.Environmental conservation can help conserve limited natural resources.

Landscape developmentGeologic features can be represented by photographs, as well as topographic and geological maps.Maps are interpreted using scales and colors to represent features.Topographic maps indicate locations of equal altitude using contour lines.Geologic maps use colors and symbols to represent rock ages and structures.

Landscape developmentOn a topographic map, the steepness of a slope is indicated by the nearness of the contour lines.A very steep slope has contour lines very close together.A long, gradual slope has contour lines far apart.Direction on a contour map is indicated by an arrow pointing north. Distances are given by a distance scale.

Natural HazardsPeople live in risky places.A flood plain can fill up with water and carry away the work of generations.Seismic hazards are issues near faults, such as the San Andreas Fault.It is not a good idea to live on the slopes of a volcano, lest it erupt. People live near Mt. Etna, anyhow.