Geomorphic Processes PDF

Geomorphic Processes Also called Gradational Processes the comprise degradation and aggradations – they modify relief II. Exogenous → A continuum of processes – weat...

Geomorphic Processes Also called Gradational Processes the comprise degradation and aggradations – they modify relief II. Exogenous → A continuum of processes – weathering – mass wasting --- erosion --- transportation Geomorphic Processes: --- deposition → These processes are carried through by o Physical Processes which create and geomorphic agents: gravity flowing water modify landforms on the surface of the (rivers), moves ice (glaciers), waves and earth tides (oceans and lakes), wind, plants, o Endogenous (endogenic) vs. Exogenous organisms, animals and humans (Exogenic) Processes 1 Degradation Process – also called denudation processes → ROCK CYCLE a. Weathering, b. Mass wasting c. Erosion and transportation DEGRADATION PROCESSESS Weathering Mass wasting Erosion and Transportation Relationship: weathering mass wasting A. Endogenous Processes erosion and transportation Endogenous Processes are large-scale o Together these processes are responsible landform building and transforming for denudation of earth’s surface processes → They create relief Weathering, Erosion, and Mass-wasting processes igneous processes DEFINITIONS: a. Volcanism; volcanic eruptions - volcanoes Weathering, erosion, mass wasting and b. Plutonism ; igneous intrusions depositional processes occur at or near the earth's surface and produce changes Tectonic processes (also called diastrophism) to the landscape that influence surface a. Folding: anticlines, synclines, mountains and subsurface topography and landform b. Faulting: rift valleys, grebe, escarpments development and landform developmend c. Lateral faulting: strike-slip faults Weathering is the physical disintegration or chemical alteration of tocks at or near Earthquakes – Evidence of present day the earth’s surface. tectonic activity Erosion is the physical removal and B. Exogenous Processes transportation of weathered material by water, wind, ice or gravity 1  Deposit is the process by which o As the pressure is released from the weathered and eroded materials are laid surface layer, slabs of rock exfoliate from down or placed in a location that is the dome and move down slope. As they different from their source are transported down slopes, weathering These processes are all very important to erosion processes break the rocks into the rock cycle because over geological progressively smaller fragments. time weathering erosion and mass Overtime, each new layer that is exposed wasting transform solid rock into will eventually exfoliate from the bedrock sediments and soil that result in the re- Mechanical weathering: frost wedging deposition of material forming new sedimentary rocks. o Frost wedging is a mechanical weathering process caused by the TYPES OF WEATHERING freeze thaw action of water that is Mechanical (physical) weathering is trapped between cracks in the rock physical disintegration and reduction in o When water freezes, it expands and the size of the rocks without changing their applies pressure to the surrounding chemical composition rock forcing the rock to accommodate the expansion of the ice Mechanical weathering processes disintegrate o This process gradually weakens, metamorphic rocks in south Carolinas piedmont cracks, and breaks the rock through region. repetitive freeze-thaw weathering Ex. Exfoliation, frost wedging, salt wedging, cycles temperature changes, and abrasion o Frost wedging generally produces angular blocks and talus material. Mechanical Weathering : Exfoliation Talus is a term used to describe o Exfoliation is a mechanical weathering weathered rock fragments deposited process where pressure in a rock is at the base of hill slope or mountain. released along parallel alignments near o The example of frost wedging is from the surface of the bedrock and layers or pike’s peak in Colorado. The slabs of the rock along these alignments weathered fragments of rock break break off from the bedrock and move apart from the exposed rock from downhill by gravity. freeze that action and collect as o Exfoliation primarily occurs on intrusive angular blocks of talus material igneous or metamorphosed rocks that are Temperature changes exposed to the earth’s surface o Exfoliation can occur both very slowly and o Daily (diumal) and seasonal temperature very rapidly in the form of mass waste. changes affect certain minerals and o Large rocks characterized by exfoliation facilitate the mechanical weathering are commonly referred to as exfoliation bedrock domes o Warmer temperatures may cause some o Table rock mountain in South Carolina, minerals to expand, and cooler enchanted rock in Texas is both examples temperatures cause them to contract of exfoliation domes with laree slabs of o This gradual expansion and contraction of rock exfoliating from the bedrock mineral grains weakens the rock causing it 2  to break apart into smaller fragments or to o In addition to the transported rocks fracture being weathered by abrasion, the o This process is more common in desert bedrock surface is also experiencing climates because the experience extreme the effects of collision and mechanical fluctuations in daily temperature changes weathering. The smoothest the o Temperature changes are often not the surface of the bedrock can also cause dominant form of weathering, but instead it to break apart temperature changes tend to accelerate o Abrasion processes in creek beds other forms of weathering already produce rounded boulders and occurring cobblers. Over time, abrasion o The rock fragments in the lower right side processes will eventually break these of this image have weathered because of rocks into progressively smaller extreme fluctuations in day and night particles sizes such as gravel, sand, temperature changes and clay Chemical weathering decomposes, Mechanical weathering: salt wedging dissolves, alters, or weakens the rock o Salt wedging occurs when salts through chemical processes to form crystallize out of solution as water residual materials evaporates. As the salt crystallize Ex. Carbonation, hydration, hydrolysis, oxidation, grows, they apply pressure to the and solution surrounding rock weakening it, until it eventually cracks and breaks down, Chemical weathering: Carbonation enabling the salt crystal to continue o Carbonation is a process by which carbon growing. dioxide and rainwater or moisture in the o Salt wedging is most common in drier surrounding environment chemically climates, such as deserts. react to produce carbonic acid, a weak Mechanical weathering: Abrasion acid, that reacts with carbonate minerally rock o Abrasion occurs when rocks collide o This process simultaneously weakens the against each other while they are rock and removes the chemically transported by water, glacial ice, wind, weathered materials or gravitational force o Carbonation primarily occurs in wet, o The constant collision or gravitational moist climates and effects rocks both on falling of the rocks causes them to and beneath the surface slowly break apart into progressively o Carbonation occurs with limestone or smaller particles. doomlike rocks and usually produce very o Flowing water is the primary medium fine, clayey particles of abrasion and it produces the rounded shape of fluvial sediments Chemical weathering: Hydrolysis o During abrasion, rocks may also o Hydrolysis is a chemical reaction weather the bedrock surface they are between H+ and OH ions in water and the coming into contact with as well as minerals in the rock. The h+ ions in the breaking into smaller particles and water react with the minerals to produce eventually individual grains. weak acids. 3  o The reaction creates new compounds but may also affect rocks with large which tend to be softer and weaker than amount of halite or rock salt. the original parent rock material o Solution of large areas of bedrock may o Hydrolysis can also cause certain cause sinkholes to form, where large minerals to expand, which also facilitates areas of the ground subside or collapse mechanical weathering processes forming depression o Hydrolysis commonly affects igneous Biological weathering is the rocks because they are composed of disintegration or decay of rocks and silicate minerals, such as quartz and minerals caused by chemical or physical feldspar, which readily combine with agents of organisms. water Ex. Organic activity from lichen, algae, rocks o Hydrolysis may also be accompanied by disintegration by plant or root growth, burrowing hydration and oxidation weathering and tunneling organisms and acid secretions processes o The hydrolysis of feldspars produces Lichen, algae, and decaying plants kaolinite, which is a clay o The weathering rinds shown on this o Organisms such as lichen and algae often sample of amphibolite illustrate the live on bare rock and extract minerals from effects of hydrolysis weathering on the rock by ion-exchange mechanisms. deposited rocks fragments to estimate the o This biochemical weathering process relative age of depositional landforms leaches minerals form the rock causing it such as river terraces or alluvial fans. The to weaken and breakdown. thicker the weathering rinds the older o The decaying of plant materials can also landform. produce acidic compounds which dissolve the exposed rock Chemical weathering: oxidation o The presence of organism growing expanding or moving across the surface of o Oxidation occurs when oxygen and the rock also exerts a small amount of water react with iron-rich minerals and abrasion and pressure that gradually weaken the structure of the mineral cause the mechanical weathering of the o During oxidation the minerals in the rock as the organism extract various rock will change colors, taking on a minerals. “rusty”, reddish-orange appearance o Similar to the chemical weathering Plant roots processes, oxidation accelerates rock decay, rendering it more vulnerable to o The most common form of biological other forms of weathering. weathering is when plant roots penetrate o The reddish orange of this sandstone is cracks and crevices of rocks and cause result of oxidation processes the rock to split or break into smaller weathering the rock. particles through mechanical weathering. o Although, the process is gradual, it can be Chemical weathering: Solution faldy effect at breaking apart rocks that may already have a pre-existing weakness o Solution occurs when minerals in rock such as fractures, faults or joints dissolve directly into water o The example of this is the growing between o Solution most commonly occurs on rocks an crevasse in a rock. The three is splitting containing carbonates such as limestone the rock along parallel planes f alignment 4  that are already weakened by foliation their source to another location where processes, a form of mechanical they are deposited weathering. o Wind erodes materials by picking them up and temporarily transporting them from Organism activity their source to another location where Differential weathering they are deposited, and either stored or re- mobilized and transported to another o Weathering rates will not only vary location. depending on the type of weather o Ice erosion occurs when particles are process, whether it is mechanical, plucked up or incorporated by moving ice, chemical, or biological but they will asl such as glaciers, and are transported vary depending on the rock material downhill, or when friction between the ice that is being weathered and bedrock erodes materials and then o Some rocks are harder than other transports them downhill rocks and will weather slower that o Gravity facilitates the down slope softer rocks transportation of loosened, weathered o The differences in rates of weathering materials and enables them to move due to different type of rocks, texture, without the acid of water, wind, or ice. or other characteristics is referred to Gravity related erosion is a major as differential weathering component of mass-wasting events o Differential weathering processes o The basin and range landscape is contribute the unique formation of influenced by several erosional processes. many landforms, including pedestals, The mountains in the background are waterfalls, and monadnocks dissected by fluvial erosion (water) and o Climate can also produce differential the sandstorm in the valley is a form of weathering responses for the same aeolian (wind) erosion. The mountains rock type. For example, limestone may contain numerous rocks falls or weathers quickly in wet climates than landslides a form of gravity related mass- dry climates. wasting erosion. o Peachtree rocks is unique pyramidal shape is a result of differential Erosion: water (fluvial) weathering associated with the → Water erodes rocks and shapes the different sedimentary sandstone rock landscapes by removing and transporting components. The top portion of the weathered materials from their source to outcrop consists of hard coarse- another location where they are deposited grained sandstone, while the lower and either stored or transported to part of the rock consist of less another location. cohesive sandstone layer. The lower → Fluvial erosion is often break into 3 distinct portion of the rock has weathered categories. Rain-splash erosion, sheet more quickly than the upper portion erosion and rill/gully erosion ultimately producing its unique pyramidal shape → Rain splash erosion occurs when the impact of a rain drop loosens and Erosion mobilizes particles → Sheet erosion is process where particles o Water erodes rocks and the landscapes by loosened buy rain-splash erosion are transporting weathered materials from 5  transported buy runoff water down the o Glacial erosion occurs when particles are slope of a surface incorporated into the glacial ice through a → Rill erosion occurs when water process referred to as plucking, and they concentrates during sheet erosion and are transported downslope within the erodes small rills of guilys into the surface glacier. that channel flow down slope o The friction and abrasion of the ice and o Fluvial erosion can occur during rainfall rock moving across the bedrock or events, from melt water runoff, or ground polished rock surfaces water percolation. Materials being eroded o The cumulative effects of glacial erosion and transported are either suspended in on a mountainous landscape can produce the water, bounced by saltation, or rolled distinct u-shaped valleys which are along the ground by traction depending on common glacial landforms a variety of conditions o Glacial erosion of this landscape has o The accumulation of fluvial erosion and carved several distinct landforms such as associated processes over a large area the glacial u-shaped valleys and the arêtes, form pathways for surface and which form the ridges between the u- groundwater flow and carves y-shaped shape valleys river valleys that continue to erode, Erosion: Gravity transport, and deposit weathered sediments across the landscape. o Gravity facilitates the down slope transportation of loosened weathered Erosion: wind (aeolian) materials and enables them to move o Wind erodes weathered rocks by picking without the aid of water, wind or ice. them up and temporarily transporting However these agents can act as catalysts them from they source to another location for gravity related erosion where they are deposited and either o Movements by gravity may be very slow or stored or remobilized and transported to very abrupt another location o Gravity related erosion can be coherent or o Erosion by wind is divided into two incoherent. Coherent refers to the erosion different categories Deflation and of a consolidated mass of materials that abrasion erode or move as single unit. Incoherent o Deflation is the movement or transport of refers to the erosion or movement of a particles through the air or along the mass of unconsolidated individual ground fragments of materials o Abrasion is the process that occurs when o Unconsolidated materials tend to wind transported particles sculpt features stabilize near an angle of 35degree in the landscape through a sand blasting (referred to as the angle of repose) like process however the balance is easily disrupted by o Aeolian erosion and deposition processes changes in environmental conditions, create a diversity of landforms including addition of weathered materials and or sand dunes, loess deposits and yardangs other adjustments that may cause mass wasting. Erosion : Ice (Periglacial and glacial) Mass wasting – is a rapid form of erosion that o Ice erosion occurs in combination with works primarily under the influence of gravity in periglacial and glacial processes 6 combination with other erosional agents. Mass times they carve out new paths as they wasting occur depending on the type of event flow downhill → Slump – Slumps are fairly common form → Rock falls when rocks dislodged, of mass wasting where the rock or soil because their change in potential energy collapses, break off from hill slope, becomes to great to maintain and the rotates slightly , and slumps downhill potential energy becomes kinetic energy → If the slump occurs as a large which causes the rock fragments to fall, consolidated mass materials it is restoring equilibrium. As result the rocks considered coherent, if it occurs as mass fall, roll or bounce down hill of unconsolidated materials or sediments → The rocks may be loosened by recent it is referred to as incoherent rainfall or snow melt-water event that → Slumping can cause damage to houses, facilitates the movement of the rock roads and other infrastructure before they fall from the force of gravity → Creep – is the slowest mass wasting → Rock falls often form piles of loose rock process and involves a very gradual below their sources and are sometimes downhill movement of soil, bedrock, and referred to as talus or screen. weathered rock fragments → Large volumes of talus may form a talus → Usually the entire slope is slowly creeping slope, talus apron, talus cone depending downhill as a complete unit on its shape. Talus tends to stabilize near → Creep processes occur to some degree on an angle of 35degree (referred to as the nearly every hillslope because of gravity. angle of repose) or the steepest angle maintained before changes in energy lead → Creep is evident bent or extended tree to gravitational erosion. This balance is trunks that are adjusting to the slow easily disrupted by changes in movement of the soil, regolith, and environmental conditions, additional weathered material they are rooted into weathered materials or other factors that → Freeze-thaw cycles and saturated lead to mass wasting. conditions may accelerate creep → Landslides – are mass wasting events processes but usually only for a short where large amount of weathered rock time-period material slide down a hillslope or → Solifluction is a certain form of creep mountain side primarily by gravity related where frozen tundra soil thaw out and erosion gently flow or sag downslope → Landslide occurs very quickly and move with incredible speed and destruction, often removing or covering everything in Metamorphism is one of the geologic processes their path. in which rocks change in form, composition, and → Debris and mud flows – Debris and structure due to intense heat and pressure and mudflows are mass wasting events that sometimes with the introduction of chemically form when heavy rainfalls produce large active fluids amounts of runoff that transported eroded Metamorphism can occur along a range heat soils, sediments, and plant debris down and pressure intensities from low to high grade slope where the flows eventually spreads metamorphism out across valley bottoms. → Sometimes the debris and mudflows follow existing drainage paths and other Low grade metamorphism involves lower 7 temperature and compressional forces that below the Earth's surface results in less overall change to parent rock in many cases after low grade metamorphic Pressure changes the parent rock may still be easily Changes the composition, mineralogy, distinguishable and texture of rocks Pressure equals force per unit area ( Pressure = F/A) Slate is a low grade metamorphic rock Pressure is the force exerted over a unit generally formed by the metamorphosis area on a material Pressure increases of mudstone, shale, or sometimes with depth as the weight and thickness of volcanic ash, under relatively low the overlying rocks increases pressure and temperature consitions Chorite Pressure during metamorphism is albite manifested by two different forces: 1. Muscovito Confining/Lithostatic pressure (Vertical High grade metamorphism results in a rock total stress or body force) – Forces are applied transformation of the parent rock into new rock equally in all whereby its original parent rock source is difficult to identify directions ( Gravity and weight ) as Granilote is high to very grade a results individual grains are compressed metamorphic rock that displays a closer and closer together. Extreme confining granular texture usually consisting of pressures that occur at great depths may even quartz, plaglociase, pyroxene, garnot and cause ions in the minerals to recrystallize and alslllcate mineral called silimantle form new minerals Gneiss, Schist, Amphibolite 2. Differential Pressure (Directed or surface force) - operates across a surface and occurs Factors involved in metamorphism when rocks are compressed or extended along a (heat temperature, pressure, chemical single plane (push-pull forces). As a result the active fluids) rocks are shortened or extended in the direction the pressure is applied Heat/temperature Heat affects the rocks chemical composition mineralogy and texture heat provides energy for chemical Chemically Active fluids Chemically active fluids reactions to proceed results i. new that are present between minerals grains during minerals to form from original minerals in metamorphism act to facilitate ion movement the source rock. and the recrystallization of existing and new minerals. Chemically active fluids have the Heat involved in metamorphism comes ability to move between different rock layers and from two main sources; transport ions from one rock to another before 1. heat transferred during contact they recytallize. metamorphism from magma or igneous intrusions 2. Progressive temperature increase Different types of metamorphism associated with geothermal gradient as Contact/thermal metamorphism Dynamic rocks are trasported to greater depths Metamorphism Reguonal Metamorphism 8  Conract/Thermal Metamorphism occurs when regional scale. It is caused by burial deep in the parent rock is intruded by magma (usually an crush and is associated with large scale igneous intrusion. Metamorphic changes under deformation and mountain building. It is the these conditions are primarily the result of most sidespread form of metamorphism. temerature canges associated with the intruding Gneiss magma. In adittionally, when hot ion-rich water Schist circulates through fractures in a rock. It can also Slate cause chemical changes to the parent rock. These heat-driven, chemical reactions occur with igneous activity and the presence of water Marble Hornfels Quartzite Dynamic MEtamorphism o When rock undergoes metamorphism due to extreme pressure o Only a result of shear stress and pressure o Only metamorphic process will extremely low temperature comparatively o Extreme pressure and stress mechanically changes a rock or mineral o No chemical reactions, no added heat, and occurs in a small spot along the fault- not region Foliated metamorphic rocks – such Gneiss, phyllite, schist, and slate have layered or banded appearance that is produced by exposure to heat and directed pressure Regional Metamorphism – occurs when rocks are sunbjected to both heat and pressure on a 9 DESCRIBE WHAT HAPPEN WHEN MAGMA IS strong enough and there are cracks in the earth's FORMED crust. Magma that came out to the surface of the earth is called the eruption MAGMA – is the molten or semi molten rocks beneath the surface of the earth. Its temperature WHAT HAPPENS AFTER MAGMA IS FORMED? ranges from 700C to 1,300C. Once magma is formed, it continues to rise When magma reaches surface. It is referred to as because it less dense than the solid rock around lava it. Magma can then accumulate in magma chambers before making its way to earths surface where it is considered lava. When magma HOW MAGMA FORMED? allowed to cool, it crystallizes into a solid form. The rocks made from the cooling and solidifying The process where magma came from is called of molten rocks are called igneous rocks. MAGMATISM. Magmatism is the process under the earth’s crust where formation and movement of magma occur. It happens in the Igneous rocks has two types to describe what asthenosphere. happens after the magma is formed; Rocks undergo partial melting because the VOLVANISM minerals that compose them melt at different temperature. Partial melting takes place because PLUTONISM rocks are not pure materials. As temperature VOLCANISM the geological phenomena that rises, some minerals melt and others remain occurs on the surface of the earth. Volcanism is solid. If the same conditions are maintained at the eruption of magma onto the surface to form given temperature the same mixture of solid and extrusive igneous rocks melted rock is maintained PLUTONISM refers to all sorts of igneous PARTIAL MELTING different minerals in rock melt geological activities that take place below the at different temperature and pressure it occurs in earth's surface. Plutonism refers to the process the lower crust and upper mantle of magma crystallizing below earth's surface to MAGMA ESCAPED INTO TWO FORMS form intrusive igneous rocks Intrusion 2 TYPES OF ROCKS Extrusion VOLCANIC ROCKS - are rocks formed when lava cools and solidifies on the earth's surface INTRUSION – is magma that moves up into a volcano without erupting. Like a balloon, this PLUTONIC ROCKS - are rocks formed when causes the volcano grows on the inside. What is magma cools and solidifes below the earth's meant by the intrusion of magma is the inclusion surface of the rock layers forming the earth's crust WHY’S THE EARTH’S INTERIOR IS HOT (magma does not get out) Heat Energy – It is the result of the movement of EXTRUSION – is an eruption of magmatic tiny particles called atoms, molecules or ions in materials that causes land formation on the solids, liquids and gases. Heat energy can be surface of the earth. Magma extrusion causes the transferred from object to another. The transfer of formation of volcanoes when the gas pressure is 10 flow due to the difference in temperature Texture of rocks due to changes in pressure between the two object is called heat and temperature (metamorphism) THERE ARE TWO SOURCES OF HEAT IN OUR METAMORPHISM - is the change that takes place PLANET; within a body of rock as a result of it being subjected to conditions that are different from 1. Primordial heat those in which it is formed. It is from the Greek 2. Radiogenic Hear word “meta” means change and “morphe” means form. - the process by which existing rocks are 1. PRIMORDIAL HEAT – The internal heat energy transformed into new types of rocks due to that gradually gathered together by means of changes in temperature, pressure, and dispersion in the planet during its year of the presence of chemically active fluids. evolution IMPORTANCE OF PRESSURE AND 2. RADIOGENIC HEAT – The thermal energy TEMPERATURE released as a result of spontaneous disintegration of natural radioactive elements PRESSURE - influences the structure and such as uranium, thorium, and potassium. arrangement of minerals in rocks. Under high pressure, minerals become denser, and foliations (layering) may form as minerals align THREE PROCESS OF HEAT TRANSFER perpendicularly to the direction of stress. 1. CONDUCTION – Governs the thermal TEMPERATURE - plays a key role in the growth of conditions in almost entire solid portion of new minerals, the breakdown of unstable the earth and plays a very important role in minerals, and the plasticity of rocks, which the lithosphere. allows them to deform. - Heat from the earths core and radiation from the sun is transferred to the surface of the earth by conduction higher pressure results in denser rocks and 2. CONVECTION – mineral alignment, while higher temperature 3. RADIOTION – the process of heat causes minerals to grow or change composition, exchange between the sun and the earth, defining the metamorphic processes. through radiotion controls the temperatures at the earths surface TYPES OF METAMORPHISM Contact Metamorphism - Occurs when rocks are heated by nearby magma or lava. - Found near igneous intrusions (magma chambers, volcanic dikes - High temperature, low pressure. - Results in non-foliated rocks like marble and hornfels. - EX: Limestone turning into marble. 11  Lithostatic pressure - leads to uniformly compacted textures, while differential pressure can cause deformation. Time - Longer periods allow for more complete recrystallization and the development of larger minerals. Regional Metamorphism - Caused by large- - Prolonged exposure to heat and pressure scale tectonic forces, such as mountain building. results in coarser-grained textures. - High temperature and high pressure. Fluid presence - Fluids (water, CO₂) act as - Produces both foliated (layered) and non- catalysts, speeding up chemical reactions. foliated rocks. - Fluid-rich environments promote the - Occurs over large areas, usually at formation of new minerals, affecting rock convergent plate boundaries. texture. Hydrothermal Metamorphism - Occurs when COMMON TEXTURES OF METAMORPHIC hot, chemically active fluids (often water) alter ROCKS the mineral composition of rocks. Foliated Texture - Characterized by the - Hot fluids permeate rocks, promoting alignment of minerals into planes or bands. chemical reactions - Alters basalt to serpentinite, or creates - Results from directed pressure causing mineral deposits (e.g., copper, gold). minerals to align perpendicularly to the - Plays a role in forming ore deposits. force. - Rocks exhibit a layered or banded Remember; appearance. - heat from magma in contact - Common in regional metamorphism. metamorphism Examples of foliated rocks: - tectonic forces in regional metamorphism - chemical fluids in hydrothermal - Slate: Fine-grained with perfect cleavage. metamorphism - Schist: Coarser-grained with visible mineral layers. FACTORS INFLUENCING TEXTURE - Gneiss: Alternating light and dark mineral Temperature - High temperatures cause mineral bands. recrystallization, leading to coarser textures. Non-foliated texture - Rocks that do not exhibit - Promotes the growth of larger, more a layered or banded appearance. stable minerals. - formed under uniform pressure or when Increased pressure - Increased pressure results minerals grow without directional stress. in denser textures and aligns minerals, producing - Typically granular or massive in foliation (layering). appearance, with equidimensional crystals. Directed pressure - Directed pressure causes - Common in contact metamorphism. minerals to reorient, creating foliated textures like in schist or gneiss. Examples of non-foliated rocks: 12  Marble: Recrystallized limestone, often Stretching: Rocks tend to elongate and smooth and granular. thin. Quartzite: Hard, interlocking quartz grains. Faulting: Can lead to normal faults, where the hanging wall moves down relative to the footwall. HOW ROCKS BEHAVE UNDER DIFFERENT TYPE Formation of Rifts: Extended regions can OF STRESS SUCH AS COMPRESSION, PULLING form rift valleys APART AND SHEARING ROCK STRESS - Stress is the force applied to a rock and may cause deformation. The three main types of stress are typical of the three types of plate boundaries: which is the convergent boundary, divergent boundary, and the transform boundary Types of rock stress COMPRESSION STRESS - Compressional stress SHEAR STRESS - Shear stress is a type of stress is when a rock is pressed together into itself, like that occurs when rocks are subjected to forces when crust movements cause two rocks to that cause them to slide past each other in squeeze another one between them. opposite directions. BEHAVIOR AT COMPRESSION BEHAVIOR AT SHEAR Shortening: Rocks tend to shorten and thicken. Lateral Movement: Rocks slide past each other, which can lead to the Folding: Layers of rock may bend and fold. (e.g. development of strike-slip faults. anticlines and synclines) Deformation: Can cause ductile Fracturing: If the stress exceeds the rock's deformation, where rocks bend, or brittle strength, it can lead to faulting and the formation deformation, resulting in fractures. of thrust faults. Tensional stress - Tensional stress involves SEAFLOOR SPREAD forces pulling in opposite directions, which Sonar - a device that bounces sound waves off results in strain that stretches and thins rock under-water objects and then records the BEHAVIOR AT TENSIONAL echoes of these sound waves. 13 HARRY HESS- Geologist and Navy submarine “matching stripes” on either side of the commander during Ww2 ridge The specific magnetism of basalt rock is Seafloor spread - the usual process at work at determined by the Earth’s magnetic field divergent plate boundaries, leading to the when the magma is cooling creation of new ocean floor. As two tectonic Scientist determined that the same plates slowly separate, molten material rises up process formed the perfectly from within the mantle to fill the opening. symmetrical stripes on both side of a mid ocean ridge The continual process of sea floor spreading separated the stripes in an orderly pattern. o SEAFLOOR SPREADING AND SUBDUCTION KEEPS THE SHAPE OF THE EARTH o SEAFLOOR SPREADING CREATES NEW CRUST WHILE SUBDUCTION DESTROYS OLD CRUST EVIDENCE FROM DRILL SAMPLES Describe the structure and evolution of ocean The samples obtained from the seafloor basins drill reveals that the rocks away from the ocean basins - In hydrology, an oceanic mid-oceanic ridge were relatively older basin (or ocean basin) is anywhere on Earth that than the rocks near is covered by seawater. Geologically, most of Rocks are younger at the mid ocean ridge the ocean basins are large geologic basins that are below sea level. o Rocks farther from the mid-ocean ridge are older -An ocean basin is a bowl-shaped depression in o Sediments are thinner at the ridge the earth, with complex topography along its o Rocks at the ocean floor are younger than deep seafloor those at the continents) STRUCTURE OF OCEAN BASINS EVIDENCE FROM MAGNETIC STRIPES (GEOMAGNETIC REVERSAL) Rocks farther from the mid-ocean ridge are older Sediments are thinner at the ridge Rocks at the ocean floor are younger than those at the continents) Basalt, the once molten rock that make up most new oceanic crust, is a fairly COASTAL PLAIN – A flat, low-lying and adjacent magnetic substance to a sea coast Scientists discovered that the magnetism -coastal plain is a flat, low-lying piece of of the ocean floor around mid-ocean floor land next to the ocean. Coastal plains are around mid-ocean ridges was divided into separated from the rest of the interior by 14  nearby landforms, such as mountains. In western South America, a large coastal plain lies between the Andes Mountains and the Pacific Ocean. - -a plain extending inland from a seashore commonly the result of geologically recent emergence of the land - when the ocean level falls, the land is - A continental shelf extends from the exposed, creating a coastal plain. coastline of a continent to a drop-off point called the shelf break. From the CONTINENTAL SHELF – A zone adjacent to a break, the shelf descends toward the continent deep ocean floor in what is called the continental slope. Even though they are underwater, continental shelves are part of the continent. CONTINENTAL RISE – it is the base of the continental slope - A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island is known as - A continental rise consists mainly of silts, an insular shelf. mud, and sand, deposited by turbidity CONTINENTAL SLOPE - It is between the outer flows, and can extend for several edge of the continental shelf and the deep ocean hundreds of miles away from continental margins. Although it usually has a smooth surface, it is sometimes crosscut by submarine canyons extending seaward of continental slope regions. ABYSSAL PLAIN - Comes from the word floor "abyss" meaning very deep and is a small elevated land form that rises from the depths - Continental slopes are regions of steeply of the ocean. sloping seafloor that lie between continental shelves and the deep ocean basins (Figure 2). Regional gradients are typically 2–5°, but locally slopes may be much steeper. CONTITENTAL BREAK – a boundary between the continental slope and shelf. - Abyssal plain is an underwater plain on the deep ocean floor, usually found at 15  depths between 3,000 and 6,000 metres mountains, causing earthquakes, and (9,800 and 19,700 ft). forming volcanoes on the seafloor and on - The term 'abyssal plain' refers to a flat land. region of the ocean floor, usually at the VOLCANIC ARC - A chain of volcanoes form base of a continental rise. above a subducting plate. SEAMOUNT AND GUYOTS Seamount - is a large submerged volcanic mountains. Guyots- is a flat top seamount - Volcanic arc is a chain of volcanoes, hundreds to thousands of miles long, that forms above a subduction zone. An island volcanic arc forms in an ocean basin via ocean-ocean subduction. The Aleutian - A seamount is an underwater mountain Islands off the coast of Alaska and with steep sides rising from the seafloor. the Lesser Antilles south of Puerto Rico In marine geology, a guyot (/ˈɡiː.oʊ, are examples. A continental volcanic arc ɡiːˈoʊ/), also called a tablemount, is forms along the margin of a continent an isolated underwater volcanic mountain where oceanic crust subducts (seamount) with a flat top more than 200 beneath continental crust. m (660 ft) below the surface of the sea. 6 STAGE OF OCEAN BASIN EVOLUTION The diameters of these flat summits can exceed 10 km (6 mi). Guyots are most Wilson cycle - The Wilson Cycle explains the commonly found in the Pacific Ocean, but process of the opening (beginning) and the they have been identified in all the oceans closing (end) of an ocean. The processes, is except the Arctic Ocean. They are driven by Plate Tectonics. The Wilson cycle, is analogous to tables (such as mesas) on named after the Canadian geophysicist John Tuzo land Wilson (1908-1993). The Wilson cycle is divided into 6 stages. TRENCH - A long narrow, steep-sided depressions on the ocean floor. 1. Embryonic Ocean Basin, 2. Juvenile Ocean Basin, 3. Mature Ocean Basin, 4. Declining Ocean Basin 5. Terminal Ocean Basin and 6. Suturing (Continental collision). - Ocean trenches are steep depressions in the deepest parts of the ocean [where old EMBRYONIC STAGE - This is the first stage of ocean crust from one tectonic plate is ocean basin formation, where rift valley creation pushed beneath another plate, raising results from the splitting of the continents. For 16 example, the Great Rift Valley and Eastern Africa were developed by this process. DECLINING STAGE - In this stage, the closing of basin starts. It is a continuous subduction. And as a result, the ocean’s bottom and ocean ridge are being removed. The Pacific Ocean serves as Active rifting- Conductive heating from the mantle plume, heat transfer from magma one example of the declining stage. generation, or convective heating may cause the lithosphere to thin. If heat fluxes out of the asthenosphere are large enough, relatively rapid thinning of the continental lithosphere causes isostatic uplift. Tensional stresses generated by CONVERGENT PLANTE BOUNDARIES the uplift may then promote rifting Oceanic-oceanic- two oceanic plates collide. Passive rifting-: Tensional stresses in the The older plate is subducted under the younger continental lithosphere cause it to fail, allowing plate, as the older plates are cooler and thus hot mantle rocks to penetrate the lithosphere. denser. Crustal doming and volcanic activity are only secondary processes. JUVENILE STAGE - Due to the division of the continental tectonic plates, sea-floor basalts are formed in this stage. This technique is what created the Red Sea. The juvenile stage causes the oceanic crust, which has a thin and dense structure, to exist below sea level. Oceanic- continental-This means that the oceanic plate sinks beneath the continental crust, forming a deep ocean trench. MATURE STAGE - The ocean basin experiences broadening, trench formation, and the beginning of subduction during the mature stage. The Atlantic Ocean was formed because of this process. TERMINAL STAGE - The uplift and the convergence are the movements that appear and 17 take place in the terminal stage. The ocean basin TECTONIC PLATES becomes narrow as a result of the uplift and convergence it experiences. Additionally, the ocean basin that has been formed is shallow at the terminal stage. Major and Minor Plates -North and South -Juan De Fuca Plate SATURING STAGE - At this stage, a collision of -American Plates -Cocos Plate continents is what transforms young mountains into mature mountains. Following the -Pacific Plate -Nazca Plate destruction of the seafloor and the collision of the -Eurasian Plate -Arabian Plate continents, a chain of continental mountains will either be formed or generated. The Himalayas -African Plate -Caribbean Plate and Tibetan Plateau are two examples of -Indo-Australian - Philippine continental collisions. Plate Sea Plate -Antartic Plate -Scotia Plate -Somali Plate Convergent boundaries occur when plates move towards one another PLATE MOVEMENTS AND BOUNDARIES THEORY OF PLATE TECTONICS - The Earth’s surface is composed of thick plates that moves constantly to reshape the Earth’s landscape. The system of ideas plate tectonics theory suggests VOLCANOES - -typically form at divergent that Earth’s outer shell (litosphere) is divided into boundaries (where plates pull apart, allowing several plates that glide over the Earth’s rocky magma to rise) or convergent boundaries (where inner layer above the soft core (mantle). an oceanic plate subducts, melting and TECTONIC PLATES - -are gigantic pieces of generating magma). Earth’s crust and uppermost mantle. They are MOUNTAIN RANGES -typically formed at made up of oceanic crust and continental crust. convergent boundaries where two continental plates collide. TRENCHES - Deep oceanic trenches form at convergent boundaries, particularly where an oceanic plate is subducted beneath a continental plate or another oceanic plate. 18 Folds - are bends or curves in rock layers that occur due to tectonic forces. When tectonic plates compress and push against each other, the stress can cause the rock to deform rather than break. Folding - is when rock layers bend instead of breaking due to pressure from tectonic forces. RIFT VALLEYS - form at divergent boundaries, This usually happens when tectonic plates push where tectonic plates are moving apart. against each other. Tectonic Forces -are the forces that cause the Earth's lithosphere to move and deform. These forces are primarily driven by the internal heat of the planet. As the folds form, there are types created – Anticlines, synclines, monovlines, overfolds, and recumbent folds Transform - Transform boundaries grind past ANTICLINES - An upward-arching fold with older each other. Causing them to create faults. rock layers at the core. Faults - occur when there is a fracture in the SYNCLINES - A downward-arching fold with Earth’s crust due to stress from plate movements. younger rock layers at the core. There are different types of faults: MONOCLINES - A fold with a steep dip on one NORMAL FAULTS - Occur when two blocks of the side, creating a step-like structure. crust are pulled apart, typically at divergent boundaries. OVERFOLDS - An overfold is a type of fold in rock layers where one side is pushed over the other, REVERSE FAULTS - Form when two blocks are making it tilt steeply. pushed together, causing the hanging wall to move upward. RECUMBENT FOLDS - A fold that has been tilted to a horizontal position, often resulting in nearly STRIKE-SLIP FAULTS - Characterized by horizontal layers. horizontal movement, these faults occur at transform boundaries where plates slide past one another. Divergent - Divergent boundaries occur when two tectonic plates move away from each other. Plate Tectonics - teaches us that plates are constantly shifting 19 Plate Boundaries - are where sections of the Earth's crust fit together EARTH’S ROCK LAYERS AND FOSSILS Types of Rocks Metamorphic Rock - Metamorphic rocks are formed by the high temperature and pressure inside the earth. DESCRIBE HOW LAYERS OF ROCK (STRATIFIED ROCKS) ARE FORMED Sedimentary Rock - Sedimentary rock Is formed when sediment is compressed in layered and KEY TERMS hardened. - The horizontal layers present in most Igneous Rock - Igneous rocks are formed by hot sedimentary rocks are called STRATA magma that has cooled over time. - Rocks that hardened over time create layers that make it a STRATIFIED ROCK - The process of creating layers of rocks is called STRATIFICATION Common Structures and Textures of Stratification Sedimentary Rocks - Sedimentary rocks Fossils - Fossils are the remains of plants and have the general character of occurring in animals who lived in the past. They are often the form of series of beds. This preserved in sedimentary rock and other phenomenon is known as Stratification" substances. or "Bedding". Types of Fossils Trace Fossil - A trace fossil is evidence left behind, like footprints or feces. These give us an idea of how animals may have lived. Cast and Mold - A cast is made when a mold is filled in with sediment. A mold is a space left behind in rock that is a hollow impression of the fossil When the thickness of individual beds is very small it is called "lamination". True Form Fossil - A true form fossil is created when part of the creature, like bone is preserved in a substance. 20  This is an inherent, primary character of - process by which sediments SETTLE in a certain sedimentary rocks is not a continuous place after being eroded process. But occur in stages like COMPACTION - deposited sediments will begin deposition of sediments ceases to stick to one another, cemented together with temporarily and then, after some time, the clay, other minerals and fossils, and compacted deposition is resumed. creating a layer of sedimentary rock. This short break in sedimentation is CEMENTATION - a process where sediment is represented by the bedding plane. chemically glued together when minerals Bedding plane is the plane of contract precipitate from the water they are dissolved in between any two adjacent beds of strata. and fill the pore space between compressed Unstratified Rocks- These rocks are not sediment. stratified. They possess crystalline and compact grains. They cannot be split in to thin slab. Granite, trap, marble etc. are the examples of this type of rocks. IGNEOUS AND METAMORPHIC - Igneous and metamorphic rocks are example of unstratisfied rocks LAW OF HORIZONTALITY - which states that PROCESS OF STRATIFICATION ON ROCKS sediments are deposited horizontally creating horizontal strata or layers. WEATHERING - rocks are broken down into smaller pieces. - The oldest layers are at the bottom and the newest layers are at the top. If you were to dig - the process of wearing or being worn by long down through the layers, you would be going back exposure to the atmosphere. in geological time. Example: wind, water, and changes of heat/temperature. - the process of wearing or being worn by long exposure to the atmosphere. EROSION - process of transporting rock particles the history of the and other materials from one place to another. earth during - the geological process in which earthen materials are worn away and transported by natural forces such as wind, water, gravity and geologic time etc. DEPOSITION - when rocks or particles of soil or silt are carried from one location and placed in another, usually by moving water or wind. - process by which sediments settle in a certain place after being eroded 21 RELATIVE AND ABSOLUTE DATING Methods used to determine the age of stratified Law of Inclusion – The rocks that mixed up in the rocks formation of sediments are called inclusions Relative dating – relative dating is the method for Inclusions – are pieces of one rock that is determining the approximate age of a structure contained within another based on its physical relationship to surrounding Consequently, the one the pieces are from is geologic structures. With an understanding of older than the one the pieces are in. rock formation, geologists can sequence structures to determine the order of events and relative age. we determine which things are older or younger based on which Faunal Succesion - Fossils of plants and animals event or fossil came first, second are grouped according to the period if geologic & third time they appeared Absolute dating - Absolute dating Is a method of - Strata containing these group of determining the numerical age of rocks or how fossils are also formed on that much time has passed since rocks formed, by particular period of time measuring the radioactive decay - first recognized by William Smith Determining event's actual time or actual age of rock using radioactive decay - different strata contain particular assemblage of fossils by which rocks may be PRINCIPLES OF RELATIVE DATING identified and correlated over long distances law of super position - States that each layer of sediments is piled on top of another layer making the one on top of the strata the youngest one, while the layer at the bottom of the strata as the oldest. Younger rocks are on top, older rocks are on bottom law of original horizontality - Layers of Ex. Grand canyon sediments are originally deposited horizontally. Law of cross cutting relationship – States that Those strata that are not found in horizontal order igneous intrusion is always younger than the rock may have been deformed by the movement of the it cuts across earth's crust. 22 Determining absolute age of rock Radiometric dating - Radiometric dating calculates an age in years for geologic materials by measuring the presence of a short- life radioactive element, e.g., carbon-14, or a long-life radioactive element plus its decay product, e.g., potassium 14/argon-40 half life - It is the time half the radioactive nuclei in any sample to undergo radioactive decay. After two half lives there will be one Fourth the orig sample after three half lives one eight the original sample and so fourth 23  Ideya – bagay na bibubuo o inilalarawan sa isip lamang Pagpapalawig – pagpapahaba ng talakay upang mas maintindihan ng mambabasa tulad ng pagbibigay ng depinsyon PANANALIKSIK Ang sulating malalimang pagtalakay saisangtiyakatnaiibang paksa. Constantino at Zafra (2010), ang pananaliksikayisangmasusing pagsisiyasat at pagsusuri ngideya, konsepto,bagay, tao, isyu, at iba pang ibigbigyanglinaw,patunayan o pasubalian. Galero-Tejero (2011), ang pananaliksikaymaytatlongmahahalagang layunin: una, isinasagawaitoupangmakahanap ng isang teorya; pangalawa, mulasapananali ksi k ay malalaman omababatidangkatotohanan sa teoryang KUMUNIKASYON ito; pangatloisinagawaangpananaliksik upang makakuha ng Definitions; kasagutansamgamakaagham na Paksa – bagay na pinaguusapan o tinatalakay problema o suliranin. Panahon – oras na inilalaan sa pagaaral Limitasyon – ito ang saklaw ng pagaaral o Mga hakbang sa pagpili ng paksa pagbibigay hangganan 1.Alamin kung ano ang inaasahanolayuninng Balangkas – banghay ng pagaaral sulatin. Layunin – anumang ninanais o adhikain na 2.Pagtatala ng mga posiblengmagingpaksapara makuhang mga kasagutan sa sulating pananaliksik. Datos – kalipunan ng mga talang ginamit na 3. Pagsusuri sa mga itinalangideya batayan sa pagtiyak ng katotohanan sa anumang 4. Pagbuo ng tentatibong paksa. isusulat 5. Paglilimita sa paksa. Mangalap - magtipon o mangolekta ngmgadatos para sa pananaliksik. Mga tip o paalala sa pagpili ng paksa Ebidensiya – saligan ng paniniwala o katibayan o Ang paksa ay ang pangkalahatan o sentral ng pagaaral na ideyang tinatalakay sa isang sulating pananaliksin napakalaking bahagi sa Sipi – anumang kinopya mula sa ibang pagkakaroon ng matagumpay na sulating akdanamaykarampatang pagkilala sa awtor o pananaliksik. itinala ayonsasinasabing ibang tao. 24  o Mahabang panahon ang ginugugol sa Persepyon sa mga taong may tattoo sa pangangalap ng datos kaya naman katawan makakabuting napag-isipang Mabuti ang Nilimitahang paksa paksang tatalakayin bago pa magkaroon ng pinal na desisyon Persepyon ng Kabataan sa mga taong o Paksang marami kang nalalaman – May may tattoo sa katawan mga kabutihan ang pagpili ng paksang may malawak ka nang kaalaman sapagkat Lalo pang nilimitahang paksa batid mo na kung saan ka kukuha ng mga Persepyon ng mga Kabataan na nasa gamit na kakailanganin mo sa pagbuo nito edad 13-19 sa mga taong may tattoo sa tulad ng mga aklat, datos, o mga taong katawan eksperto na nasabing paksa bago pa man simulant ang pananaliksin. URI AT MGA HALIMBAWA NG SALIKSIK o Paksang gusto mo pang higit na Action Research – ito ay ginagamit upang makilala o malaman – Madalas, may mga makahanap ng solusyon sa mga espesipikong tao kang higit na gusto pang makilala o problema o masagot ang mga espisipikong mga mga bagay na hindi gaanong alam at tanong ng isang mananaliksik na may kinalaman gusting-gusto mo sanang higit pang sa kanyang larangan. Ang result anito ay malaman o makilala. ginagamit ding batayan sa pagpapabuti ng bagay o Paksang napapanahon – Maraming na siyang paksa ng saliksik. kabutihan maidudulot ang pagpili ng mga paksang napapanahon. Magiging Tunay nga bang Epektibo ang OBE sa makabuluhan ang anumang magiging Lalong Pagkatuto ng Mag-aaral sa resulta ng iyong pananaliksik sapagkat Arkitektura. magagamit ito ng nakakarami dahil Anong Estratehiya sa Pagtuturo ang angkop o tumutugma ito sa kasalukuyang pinakaepektibo sa pagkatuto ng mgamag- pangangailangan. aaral na may suliranin sa Pandinig. Paglilimita sa Paksa: Deskriptibo – And deskriptib na disenyo ng pananaliksik ay maaring gumamit ng ibat ibang Malawak o pangkalahatang paksa paraan ng pananaliksik upang masuri ang isa o Labis at Madalas na Pagpupuyat ng mga higit pang mga baryabol. Ito ay naglalayong Mag-aaral mailarawan ng tumpak at sistematiko ang Nililimitahang paksa popilasyon, sitwasyon at phenomena (McCombes, 2022) Mga dahilan sa labis at madalas na pagpupuyat ng mga magaaral at ng epekto Persepyon n mga magaaral sa divorce bill nito sa gawaing pang akademiko. Mga dahilan sa labis at madalas na pagpupuyat ng mga magaaral sa Lalo pang nilimitahang opaksa ikasampung baiting ng tanay national Mga dahilan sa labis at madalas na highschool at epekto nito sa kanilang pagpupuyat ng mga mag-aaral sa gawaing pangakademiko ikasampung baiting ng tanay national high Historikal – Historikal na pananaliksik, ito ay school at epekto nito sa kaniulang isang sistematikong disenyo ng pangangalap at gawaing pang akademiko pagtataya ng datos na may layuning ilarawan, Malawak o pangkalahatang paksa ipaliwanag at unawain ang mga aksiyon at 25 pangyayari sa nakalipas sa pinagtugmang Keep in mind that an effective speaker interpretasyon. will always consider his or her audience’s interest. - Ang historical na pananaliksik ay gumagamit ng ibat ibang pamamaraan ng pangangalap ng datos 2. Analyze the audience – Audience analysis is upang makabyuo ng mga kongklusyon hinggil sa the process of examining your audience nakaraan. Batay sa mga datos at ebidensya, according their demographics, attitude, and pinalalim ang pagunawa sa nakaraan. interest. Pag-unlad ng wikang Pambansa Demographics refer to the Pag-unlad ng general edicatin curriculum characteristics such as gender, race, as sa kolehiyo gender, education, age, etc. Some Pagkakatatag ng simbahan ng banal na speakers are surprised when their speech krus making and deliver fail when they did not San Ildefonso church consider audience demographics. Feasibility study – Ang feasibility ay naglalaman Audience attitude is another factor to consider. Is your audience’s attitude ng nakolektang datos ay nagbibigay ng mga favourable, indifferent or opposed? konklusyon a topinyon ng proyekto An audience with a favourable attitude Kalakasan, kahinbaan, oportunidad, banta will express interest and support. They ORALCOMUNICATION often raise relevant questions or reaction that help deepen the discussion of the Lesson 1: Principles of speech writing topic. 3. Source the information – 1. Choose a Topic – The topic is the subject of Supporting information refers to the ideas your speech, the idea or concept you want to that develop your topic. To make sure that share to your audience. your supporting is adequate and reliable. You have to know more than your audience does. Your supporting information should be pertinent Your supporting information Know which aspects of your topic are should vary. worth sharing Use examples, charts, graphs and/or Research about your topic. information technology to show variety in Make sure your audience will be your presentation. Video clips, animation interested in what you have to say. may be used to draw their interest. This will be obvious from your gestures, facial and vocal expressions. 4. Organize and outline the speech contents – Organizing your speech contents is important for Make sure that your audience two reasons: understands the value of your speech topic to their lives. Explain it to them at the a. It helps your listener to understand the beginning of your speech. Emphasize it in connection between your ideas. the middle. Then repeat it in the end. 26 b. It helps you ensure that all supporting - Intends to educate the audience through information you have gathered will support and providing information about a particular topic or develop your main point. subject. Outlining helps you plan your speech by KINDS OF INFORMATIVE SPEECH: providing a tentative framework of what you are 1. Descriptive Speech – Provides a vivid going to say. picture of a person, a place, or an object. PREPARATION OUTLINE – Is an outline helps you Provides an image of the subject in the prepare the speech. This stage in the speech audience’s minds through sensory details process helps you decide what you put as your such as sight, sound, smell, touch, and introduction, body and conclusion. use. REMEMBER: In writing the preparation 2. Explanation Speech – explains or outline, remember to label the parts of your defines a concept, term, or an abstract speech (IBC). Also use a uniform pattern of topic. Provides facts, etymology of words symbolization. All main point should use roman or concepts, classification, examples, numerals. Subpoints can be marked using capital and other relevant details. letters. Finally, keep in mind that since it is an 3. Demonstration Speech – Presents outline, feel free to change the order of your ideas information about how to do something or as well as the content of the speech. how something is done. It gives the audience information of a certain process. Lesson 2. Types of Speeches 4. Reportorial Speech – Describes or explains an event or an issue that is SPEECH – Any type of formal/informal discourse interesting, significant, or unusual. It intended to delivered or orated to audience/s. helps to explain to the audience what PUBLIC SPEAKING – The act of speaking in front happened, why it happened and what of a sizable number of people. Involves a single resulted from the event. It also promotes speaker and an audience. And, speaker is tasked understanding by presenting the reasons to deliver a message or a speech of general for why an issue exists and what its interest. implications and effects are. TWO TYPES OF SPEECH: 2. PERSUASIVE SPEECH - Aims to influenced the audience to accept the speaker’s position or A. Types of Speech according to purpose stand on an issue. - Speaker’s goal is to convince 1.EXPOSITORY/INFORMATIVE SPEECH - Aims to or encourage audiences to accept a perspective. provide the audience with information about a KINDS OF PERSUASIVE SPEECH: topic or to expand their knowledge about a topic with which they are already familiar. 1. Convincing Speech – The speaker attempts to convince the audience to adopt his or her way of 27 thinking or to change the way they think about 2. Memorized Speech – Speech that is committed things. and delivered entirely from memory. 2. Actuation Speech – Designed to urge the 3. Impromptu Speech – Speech that is delivered audience to take a particular action. The speaker on the spot with no chance to prepare or seeks to persuade the audience to start doing the memorize. action now. 4. Extemporaneous Speech – A speech is given RHETORICAL APPEALS IN PERSUASIVE without any special advance preparation and is SPEECHES: delivered without the help of notes and others. (3 mins is the maximum time of preparation) A. Ethos – Appeal to the speaker’s credibility or authority as perceived by the audience. B. Pathos – Appeal to the audience’s emotion. C. Logos – Lesson 3. Communicative Strategies Appeal to logic or reason. GUIDELINES IN WRITING A PERSUASIVE SPEECH: Communication - is the heart of the community. Being able to use various communicative 1. Determine your goal. strategies leads to the achievement of the 2. Know your audience. speech purpose and creates a smooth flow of information between the speakers and the 3. Organize the information. listeners. Poor communication strategy allows 4. Provide strong evidence. for information blockages. Communicative strategies 3. Entertainment Speech - Aims to amuse - are plans, ways or means of sharing information audience members and put them in a jovial mood. that are adopted to achieve a particular social, political, psychological, or linguistic purpose. - Its primary focus is to entertain an audience or create a pleasant or interesting diversion. These are the strategies that people use: - May be delivered during casual dinners, parties, 1. Nomination – Employed when you try to open a graduations, and weddings. topic with the people you are talking to. You may start off with news inquiries and news VALUES INTEGRATION – The art of speaking must announcements as they promise extended talk. be anchored to reality circumstances to value the This could signal the beginning of a new topic in essence of life and the community that surrounds the conversation. it. 3. Restriction – refers to any limitation you may B. Types of Speech according to delivery have as a speaker. You are given specific 1. Reading/Speaking from Manuscript – Implies instruction that you must follow. These reading a pre-written speech, paper script or instructions confine you as a speaker and limit teleprompter. what you can say. 28 4. Turn – taking pertains to the process by which SPEECH ACTS – Are performed when a person people decide who takes the conversation floor. offers an apology, greeting, request, complaint, There is a code of behavior behind establishing invitation, compliment, refusal. Speech act is an and sustaining a productive conversation, but the act of communication. primary idea is to give all communicators a - It is an utterance that a speaker makes to chance t