Earth Science Past Paper PDF 2024-2025

RCC AND SSLG: YOUR REVIEWING BUDDY EARTH SCIENCE Prepared by: Jhanniel Quilalang | RCC Grade 11 Representative MODULE 01 WEATHERING DIFFERENT TYPES OF WEATHERING...

RCC AND SSLG: YOUR REVIEWING BUDDY EARTH SCIENCE Prepared by: Jhanniel Quilalang | RCC Grade 11 Representative MODULE 01 WEATHERING DIFFERENT TYPES OF WEATHERING https://express.adobe.com/page/h1SJSPdfHHBk8/ The different types of weathering are EXFOLIATION physical weathering, and chemical It is because of the intense heating of the weathering. rock layers. PHYSICAL WEATHERING Occurs as cracks develop parallel to the Sometimes called mechanical weathering. land surface a consequence of the is the process that disintegrates or breaks reduction in pressure during uplift and rocks apart without changing their chemical composition. erosion. It usually happens in places where there is ABRASION little soil and few plants grow. Wearing away of rocks by constant BLOCK DISINTEGRATION collision of loose particles. Successive heating and cooling which BIOLOGICAL ACTIVITY causes the expansion and contraction of rocks. Plants and animals (including humans) as FROST WEDGING OR FREEZE-THAW agents of mechanical weathering. Causes many rocks to break. CRYSTAL FORMATION OR SALT WEDGING This refers to the repeated freezing and Most water contains dissolved salts. melting of water within a small narrow When the water in rock fissures , crack or space in the rock surface. evaporates, salt crystals form and It occurs when the water seeps into the expand like ice, forcing open fissures. cracks, freezes, and expands exerting up “Salt Wedging” - most pronounced in arid to 4.3 million pounds per square root of the regions. pressure that leads to fragmentation of rock. Also occurs along seacoasts. SWIFTLY MOVING WATER Swiftly moving water temporarily lifts rocks from the stream bottom, and upon their descent, collisions with other rocks 1 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY result in the breakage of small Important in making caves. fragments. Dissolved carbon dioxide in water or moist air forms carbonic acid, and this acid PLANT ROOTS reacts to minerals in rocks. Plant roots can grow in cracks. The pressure exerted by a confined FACTORS THAT AFFECT THE RATE OF growing root can significantly enlarge WEATHERING cracks in rocks, and as roots continue to The following are the factors that affect the grow, they have the capacity to effectively rate of weathering: break rocks apart. PROPERTIES OF THE PARENT ROCK CHEMICAL WEATHERING The mineralogy and structure of rock affect its susceptibility to weathering. Chemical weathering changes the Different minerals weather at different molecular structure of rocks and soil. rates. SOLUTION OR DISSOLUTION CLIMATE Removal of rock in solution by acidic Most important factor affecting the weathering of rocks. rainwater. The extent of weathering is dependent on EXAMPLE the average atmospheric condition prevailing in a region over a long period. Limestone is weathered by rainwater SOIL containing dissolved CO2 - Carbonation. Affect the rate in which rock weathers. HYDROLYSIS Soil retention of rainwater prolongs The breakdown of rock by acidic water to chemical reactions with rocks, especially produce clay and soluble salts. those covered by soil. OXIDATION LENGTH OF EXPOSURE is the reaction of a substance with oxygen. The longer a rock is exposed to the The breakdown of rock by oxygen and agents of weathering, the greater the water, often giving iron-rich rocks a degree of alteration, dissolution, and rusty-colored weathered surface. physical breakup. Quickly buried lava flows are less prone ACID RAIN to weathering compared to those exposed Acids react with rock and strip away to the elements for extended periods. essential chemicals from the structure of minerals that rocks are made of. PRODUCTS OF WEATHERING Acids are particularly effective at removing The following are the products of calcium from minerals. weathering. CARBONATION WEATHERING The process of combining water with carbon dioxide to make carbonic acid. 2 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY The disintegration and decomposition of MANTLE rock near the Earth surface. The thickest and largest layer of Earth. EROSION Composed of very hot, dense rock. Measurements: The mantle is 1800 miles The incorporation and transportation of thick and extends down to 2,890 km. material by a mobile agent such as water, Temperature: 1600 degrees Fahrenheit at wind, or ice. the top to about 4000 degrees Fahrenheit near the bottom. DEPOSITION OUTER CORE Laying down of sediment that has been The outer core is a low viscosity fluid. transported. Composed of the melted metals nickel and iron. IMPORTANCE OF WEATHERING Measurements: 1800 miles beneath the 1. Most important in the formation of soils. crust and 1400 miles thick. 2. Major forces that shape the Earth’s Temperature: Very hot that all metals surface. turned into liquid state. 3. An important part of the rock cycle. INNER CORE 4. Provides the sediments that form The inner core experiences extreme sedimentary rocks. temperatures and pressures causing metals to be solid and tightly packed, unable to move like a liquid but vibrating in MODULE 02 place. Measurements: 4000 miles beneath the WHY THE EARTH’S INTERIOR IS HOT crust and 800 miles thick. Temperature: 9000 degrees F. and the THE EARTH’S INTERIOR pressures are 45,000,000 pounds per The Earth's interior is made-up of four square inch. layers, three solid and one liquid. WHY IS THE INTERIOR OF THE EARTH IS HOT? CRUST Heat is energy that is transferred from one body to another as the result of a difference The thinnest layer of the Earth. in temperature. Measurements: 40 km on average, ranging A movement of atoms. from 5–70 km (~3–44 miles) in depth. The faster the movement of atoms the Temperature: vary from air temperature on more heat. top to about 1600 degrees Fahrenheit (870 The heat beneath the Earth moves degrees Celsius) in the deepest parts of the continents, builds mountains and causes crust. earthquakes. The crust of the Earth is broken into many Earth’s core temperature is estimated to be pieces called plates. The plates "float" on the soft, plastic mantle around 5,000 to 7,000 degrees Celsius. which is located below the crust 3 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY uranium, which produces heat as it MAIN REASONS WHY THE INTERIOR OF THE EARTH IS VERY HOT decays, preventing complete cooling. Radioactive decay is crucial for Earth's geological activity, providing over half of its heat, and without it, there would be fewer volcanoes, earthquakes, and less formation of vast mountain ranges. HEAT FROM WHEN THE PLANET FORMED AND ACCRETED, WHICH HAS NOT YET BEEN LOST MODULE 3 Much of Earth's heat originated from its HOW MAGMA IS FORMED WITHIN THE formation 4.5 billion years ago when solid EARTH particles called "planetesimals", condensed from a gas and dust cloud in space, collided and heated the early Earth WHAT IS MAGMA? to a molten state. The Earth was formed by the process of Magma is molten material beneath or within the accretion a portion of the original heat was Earth’s crust from which Igneous rocks are trapped inside the Earth’s crust and has not formed yet been lost. And magma is a mixture of minerals, Meteoroids attracted each other and Gases like carbon dioxide, water vapor and formed bigger masses. This process sulfur. accumulated a lot of heat. Magmas form by partial melting of silicate rocks either in Earth's mantle, the continental crust or the FRICTIONAL HEATING oceanic crust. Frictional heating, caused by denser core All types of magma have a significant percentage material sinking to the center of the planet. of Silicon dioxide. Some of the heat in the middle layers of the interior are hot because the deeper core is Magma is from Ancient Greek μάγμα cooling and releasing heat. (mágma) meaning "thick unguent". Earth is gradually cooling over billions of Magma beneath Earth's surface remains years, having cooled a few hundred fluid due to high temperatures and degrees, but maintains a nearly steady pressure beneath the crust. Magmas are generally made up of only temperature due to heat generation in its eight elements; in order of importance: interior. oxygen, silicon, aluminum, iron, calcium, sodium, magnesium, and potassium. RADIOACTIVE DECAY Oxygen is the most abundant element in Earth's nearly constant temperature is magma. sustained by the decomposing of natural Magmatism is the emplacement of magma radioactive elements, particularly within and at the surface of the outer layers of a terrestrial planet, which solidifies as 4 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY igneous rocks. Due to magmatism the Rocks don't melt at a single temperature; mountains formed. they undergo partial melts over a range of temperatures, allowing the extraction of ORIGIN OF MAGMA liquid portions to form magma. Geologist concluded that magma forms when rocks reach temperatures high DRY ROCKS enough to melt them. Most rocks begin to melt at a temperature between 800 and 1200 degrees Celsius. We believed that the temperature rises as we go deeper and deeper into the Earth. As pressure increases in the Earth, the melting temperature changes as well. MELTING OF MINERALS Melting of dry rocks is similar to melting of PURE DRY MINERAL dry minerals, melting temperatures increase with increasing pressure, except there is a range of temperature over which there exists a partial melt. The degree of partial melting can range from 0 to 100%. For a pure dry (no H2O or CO2 present) ROCKS WITH H2O/CO2 mineral, the melting temperature increases with increasing pressure. MINERAL WITH H2O/CO2 Melting of rocks containing water or carbon dioxide is similar to melting of wet For a mineral with H2O or CO2 present, minerals, melting temperatures initially the melting temperature first decreases with decrease with increasing pressure, increasing pressure. except there is a range of temperature over which there exists a partial melt. MELTING OF ROCKS 5 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY In order for magma to form, wet or dry melting of rocks or minerals must occur. DRY MELTING Dry melting occurs when minerals or rocks, with no carbon dioxide or water in them, are heated to a specific temperature. https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_ This temperature increases as pressure width/public/thumbnails/image/subduction%20zone%20graphic.jpg?itok=uASZpZBl in the Earth’s layers increases. A subduction zone forms when continental WET MELTING crust and oceanic crust collide. Wet melting occurs when rocks or minerals The continental crust is thicker and more containing water are heated. buoyant than the oceanic crust so the It occurs over a variety of temperatures oceanic crust wear away beneath the rather than at only one temperature. continental crust. The temperatures in which wet melting Tectonic plates sliding into the mantle occurs decreases with increased pressure release fluids from the plate, such as or depth initially. seawater and carbon dioxide, which This temperature then starts to increase again the higher the pressure rises or the ascend into the upper plate, partially melting lower the depth is. the crust and creating magma. PARTIAL MELT HOT-SPOT VOLCANISM A partial melt can occur with both wet and dry melting of rocks but can’t occur with minerals. A partial melt occurs when only part of the rock material melts. PROCESSES THAT FORM MAGMA BY MELTING OF MANTLE ROCK Increase in temperature Decrease in pressure A hot spot is fed by a region deep within the Addition of water Earth’s mantle from which heat rises THREE DIFFERENT TYPES OF MAGMA through the process of convection. GENERATION This heat facilitates the melting of rock at the base of the lithosphere, where the brittle, upper portion of the mantle meets the SUBDUCTION ZONES Earth’s crust. Magma from hot spots rises through lithospheric plates, creating active volcanoes; as oceanic ones move away, 6 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY they cool, forming older islands and High Viscosity – flows very slowly. seamounts, while continental ones cool, Low Viscosity – flows rapidly. subside, and eventually become extinct. FACTORS THAT AFFECTS THE VISCOSITY OF MAGMA RIFT ZONES https://bis.babylon-software.com/?rt=GetFile&uri=!!8B2M8PGU6X&type=0&index=191 Rift zones are areas where the volcano is Temperature – Inversely proportional. rifting or splitting apart. Higher temperature, lower viscosity. In rift zones, the rock is weak with Chemical Composition – Directly numerous cracks, making it easier for proportional. Higher silica content, more magma to reach the surface through these viscous. pathways. Amount of dissolved gases – Inversely proportional. Loss of gases, more viscous. THREE BASIC TYPES OF MAGMA Basaltic - formed through dry partial melting of the mantle MODULE 4 Andesitic - formed through wet partial melting of the mantle WHAT HAPPENS INSIDE THE EARTH AFTER Rhyolitic - formed as a result of wet MAGMA IS FORMED? melting of continental crust. The two Igneous processes are Volcanism - volcanic eruptions, and Plutonism - Igneous intrusions. Igneous rocks - rocks that formed from the cooling and solidifying of molten rock. Plutonic Igneous Rocks - when the magma cools and solidifies within the Earth. (Ex. Granite, Pegmatite, Diorite, Gabbro, and Aplite) VISCOSITY ROCK CYCLE Viscosity is the resistance to flow (opposite Igneous rocks form by crystallization from of fluidity). Viscosity depends on primarily on the magmas in the crust or at the surface. composition of the magma, amount of dissolved gases, and temperature. 7 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Magmas of different compositions originate HUTTON’S THEORY OF PLUTONISM by a melting of different source rocks in the lower crust and mantle. Processes that create and arrange rocks Melting is controlled by source rock into the current landscape are driven by heat concealed within Earth’s interior. compositions, water contents-pressure, Rock-forming processes are constant and temperature. slow. The land was resilient to rain and wind. PLUTONISM Earth’s landscape is very slowly eroded Plutonism is defined as the process by away and deposited downhill due to which magma get out through the crust and gravity. crystallizes as an intrusive igneous rock beneath the Earth's surface. THE INTRUSIVE STRUCTURES The name plutonism references Pluto, the classical ruler. INTRUSIONS ABBE ANTON MORO Intrusions are also classified according to size, shape, depth of formation, and geometrical relationship to the country rock. Intrusions are one of the two ways igneous rock can form. Shallow intrusion is defined as intrusions that formed at depths of less than 2 https://upload.wikimedia.org/wikipedia/commons/6/6c/Medal_of_Lazzaro_Moro._Panteon_ kilometers. Veneto%3B_Istituto_Veneto_di_Scienze%2C_Lettere_ed_Arti.jpg Abbé Anton Moro, who had studied volcanic islands, first proposed the theory of Plutonism before 1750. JAMES HUTTON - Most cases, Hot magma, typically less dense than surrounding rock, tends to ascend toward the surface using various mechanisms: https://cdn.britannica.com/56/10856-004-807C3B6B/James-Hutton-Henry-Raeburn-detail-Bruntisf ield-oil.jpg - Filling and widening existing cracks James Hutton, the scientist responsible for - Melting the surrounding rock (called country rock) expounding this theory to the Royal Society - Pushing the rock aside (where the rock of Edinburgh and the general scientific is hot enough and under enough community. pressure to deform without breaking) - Breaking the rock 8 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY If the magma's viscosity is low, XENOLITHS non-explosive eruptions occur with gas Stoping occurs when magma intrudes easily expanding during a lava flow. cracks, breaks off rock pieces, and engulfs However, high-viscosity magma leads to them, creating fragments known as explosive eruptions, as pressure builds up xenoliths. inside gas bubbles, causing them to burst A xenolith is a piece of rock trapped in violently upon reaching the surface. another type of rock. TYPES OF ERUPTION PLUTON A pluton is an intrusion of magma that wells up from below the surface. EFFUSIVE (NON-EXPLOSIVE) ERUPTIONS Pluton is a generic word for any igneous Non explosive eruptions are favored by low intrusive rock body. gas content and low viscosity magmas. Plutons, with diverse shapes and If the viscosity is low, non-explosive relationships to surrounding rock, are eruptions usually begin with fire fountains named based on these characteristics. due to release of dissolved gases. EXPLOSIVE ERUPTIONS Explosive eruptions are favored by high gas content and high viscosity. Explosive bursting of bubbles will fragment the magma into clots of liquid that will cool as they fall through the air. These solid particles become pyroclasts (meaning - hot fragments) and tephra or volcanic ash, which refer to sandsized or smaller fragments. TYPES OF VOLCANIC ERUPTION MODULE 5 VOLCANIC ERUPTION/MAGMA EXPULSION HAWAIIAN Hawaiian eruptions involve low-viscosity MAGMA & LAVA basaltic magma. Gas discharge creates a fire fountain, Shallow intrusion is defined as intrusions propelling incandescent lava up to 1 km that formed at depths of less than 2 above the vent. kilometers. Molten lava flows down slope as a VOLCANIC ERUPTIONS nonexplosive lava flow. In general, magmas that are generated Very little pyroclastic material is produced deep within the Earth begin to rise because in Hawaiian eruptions. they are less dense than the surrounding STROMBOLIAN solid rocks. Strombolian eruptions involve distinct As magma rises, dissolved gas forms blasts of basaltic to andesitic magma. bubbles due to reduced pressure. 9 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Incandescent bombs are ejected, forming PHREATOMAGMATIC a cone of tephra (cinder cone) near the vent. Phreatomagmatic eruptions occur when Lava flows may erupt from vents low on the magma contacts shallow groundwater. cone's flanks. The rapid expansion of water to steam, Strombolian eruptions are mildly along with pre-existing rock fragments, explosive, generating low elevation leads to violently explosive eruptions. eruption columns and pyroclastic fall Distribution of pyroclasts around the vent is deposits. less than in a Plinian eruption. Surge deposits are typically produced in VULCANIAN phreatomagmatic eruptions. Vulcanian eruptions involve sustained PHREATIC explosions of andesite or rhyolite magma. Eruption columns can reach several km Phreatic eruptions, or steam blast above the vent. eruptions, occur when magma encounters Collapse of columns often produces shallow groundwater. pyroclastic flows. Groundwater flashing to steam is Widespread pyroclastic falls consist mainly explosively ejected along with pre-existing of angular blocks. rock fragments. Vulcanian eruptions are classified as very No new magma reaches the surface in explosive. phreatic eruptions. Surge deposits may be a result of these PELEAN eruptions. Pelean eruptions occur due to the collapse of andesitic or rhyolitic lava domes. This collapse may involve a directed blast. Glowing avalanches or nuée ardentes, in MODULE 6 the form of block-and-ash flows, are METAMORPHISM produced. Metamorphism is the change that takes Surges may occur, leaving surge deposits. place within a body of rock as a result of it Pelean eruptions are classified as violently being subjected to conditions that are explosive. different from those in which it formed. PLINIAN Metamorphic rocks typically have different Plinian eruptions involve sustained mineral assemblages and different textures ejection of andesitic to rhyolitic magma. from their parent rocks but they may have Eruption columns can extend up to 45 km above the vent. the same overall composition. Wide-spread fall deposits occur, with thickness decreasing away from the vent. METAMORPHIC AGENTS Eruption column collapse may produce pyroclastic flows and surges. TEMPERATURE Plinian ash clouds can circulate the Earth Metamorphism results from temperature, within days. originating from depth or contact with Plinian eruptions are characterized as magma. violently explosive. 10 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Metamorphic changes typically occur in the THREE WAYS THAT METAMORPHIC ROCKS temperature range of 350-850 degrees CAN FORM Celsius. Elevated temperature enhances chemical activity in rocks, facilitating reactions during CONTACT METAMORPHISM metamorphism. Occurrence: Occurs when magma comes in contact with an already existing body of PRESSURE rock. Metamorphism results from two types of Cause: When magma contacts existing pressure: uniform pressure increasing with rocks, their temperature rises, and they depth and direct pressure from tectonic become infiltrated with fluid; the affected plates. area is typically small, ranging from 1 to 10 Uniform pressure affects volume at great kilometers. depths, acting vertically downwards. Product: non-foliated (rocks without any Direct pressure from tectonic plates cleavage) rocks such as marble, quartzite, causes directional stress, squeezing rocks and hornfels. and potentially leading to folds and a REGIONAL METAMORPHISM foliated texture. Occurrence: Occurs over a much larger CHEMICALLY ACTIVE FLUIDS area. This plays a key role in different ways in Cause: This is caused by large geologic causing metamorphism. processes like Mountain-building. It Metamorphism requires the presence of a processes exert immense pressure, causing liquid medium for chemical reactions, with rocks to bend and break when exposed at water being a common carrier. the surface. Volatiles associated with magmatic Product: foliated rocks such as gneiss and bodies diffuse through surrounding rocks, schists. inducing compositional changes. DYNAMIC METAMORPHISM Magma or hot hydrothermal solutions Occurrence: Along fault zones during can directly react with rocks they come in tectonic movement. contact with during metamorphism. Cause: Intense mechanical stress and pressure. MAIN FACTORS THAT CONTROL Product: Formation of mylonites and METAMORPHIC PROCESS cataclasites. The mineral composition of the parent SIGNIFICANT VISIBLE CHANGES THAT ARE rock. PRODUCED AS A RESULT OF The temperature at which metamorphism METAMORPHISM takes place. The amount and type of pressure during Crystallization of calcareous sedimentary metamorphism. rocks ( i.e. limestone) and The types of fluids (mostly water) that are re-crystallizations of some igneous and present during metamorphism. other sedimentary rocks. The amount of time available for Formation of new minerals which are diagnostic of metamorphic rocks. metamorphism. 11 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Development of foliation with or without NON-FOLIATES segregation of mineral parent rocks. Formation of drags folds, joints, etc. are metamorphic rocks that have no during the rock failure under pressure. cleavage at all. Formation of slaty cleavage in Quartzite and marble are two examples of argillaceous rocks. non-foliates. TWO CATEGORIES OF METAMORPHIC ROCKS QUARTZITE Quartzite, originating from metamorphosed sandstone, is FOLIATES significantly harder than its parent rock Composed of abundant micas and due to the influence of deeply buried chlorites. magmas during its formation. Minerals exhibit distinct cleavage. MARBLE Foliated rocks split along cleavage lines parallel to the minerals. Marble, metamorphosed from limestone or Some examples of foliates are: dolomite rich in calcium SLATE carbonate(CaCO3), features varied a fine-grained metamorphic rock with crystal sizes and color variations perfect cleavage splits into thin sheets resulting from impurities during formation. and typically exhibits a light to dark brown streak, forming through low-grade metamorphism driven by relatively low MODULE 7 temperatures and pressures. SCHIST STRESS AND STRAIN a medium-grade metamorphic rock, Deformation is a general term for any undergoes higher heat and pressure change in the shape or volume of a rock, compared to slate, a low-grade such as when a rock is folded or fractured. metamorphic rock. Deformation occurs in building large mountain ranges at convergent boundaries GNEISS through: Emplacement of plutons, a high-grade metamorphic rock, Volcanism, Metamorphism, and undergoes greater heat and pressure Continental accretion. than schist, exhibiting coarser texture and Stress is a force of deformation. distinct banding with alternating layers Strain is the change in shape that results composed of different minerals. when stress is applied. TYPES OF STRAIN COMPRESSION 12 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Length of time DUCTILE ROCKS Ductile rocks show a great amount of plastic strain (they bend) before they In compression, the rocks are squeezed fracture. along the same line. BRITTLE ROCKS Compression shortens the rock layers by folding or faulting. Brittle rocks fracture after only a small amount of plastic strain. TENSION STRIKE AND DIP Strike and dip describe a rock layer's orientation with respect to the horizontal. Strike is the intersection of a horizontal plane with an inclined plane. In tension, the forces along the same line Dip is the maximum angle of an inclined act in opposite directions. plane. Tension lengthens the rocks or pulls Principle of original horizontality states them apart; fractures and faults form. that most rocks are originally laid down horizontally. SHEAR When we see rocks inclined, they have been deformed by folding and/or fracturing. DEFORMATION AND GEOLOGIC In shear, the forces act parallel to one STRUCTURES another, but in opposite directions. Deformation occurs along closely spaced GEOLOGIC STRUCTURES planes like the slip between cards in a deck. Geologic structures are rocks that have been deformed. ELASTIC DEFORMATION/STRAIN Deformation includes fracturing and/or Occurs if rock return to their original folding. shape when the stress is released. FOLDED ROCK LAYERS PLASTIC DEFORMATION/STRAIN Folds are layers of rock that were once Occurs when rocks fold or fracture when planar that are bent or crumpled. stress is applied and do not recover their Folds form during compression and original shape. undergo plastic strain. Folding occurs deep in the crust where WHAT DETERMINES WHETHER A ROCK WILL rock behavior is ductile. BEND ELASTICALLY, PLASTICALLY, OR FRACTURE? Type of stress applied Pressure and temperature Rock type 13 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Folds have an axial plane that divides the fold in half. Each half is called a limb. The axis is an imaginary line formed by the intersection of the axial plane and the folded beds. TYPES OF FOLD MONOCLINES A monocline is a flexure in otherwise horizontal or uniformly dipping rock layers. One limb is horizontal and the fold axis is inclined. OTHER TYPES OF FOLD ANTICLINES AND SYNCLINES Antiform: linear, strata dip away from axial center, age unknown, or inverted. Synform: linear, strata dip toward axial centre, age unknown, or inverted Chevron: angular fold with straight limbs and small hinges Recumbent: linear, fold axial plane oriented at low angle resulting in overturned strata in Anticlines are uparched folds. The oldest one limb of the fold. rocks are in the core. Slump: typically monoclinal, result of Synclines are down-arched folds. The differential compaction or dissolution during youngest rocks are in the core. sedimentation and lithification. DOMES AND BASINS Ptygmatic: Folds are chaotic, random and Domes and basins are circular to oval disconnected. Typical of sedimentary slump structures which have rock layers occurring folding, migmatites and decollement in age-position contexts which are the same detachment zones. as anticlines and synclines, respectively. Parasitic: short wavelength folds formed within a larger wavelength fold structure – normally associated with differences in bed thickness 14 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Disharmonic: Folds in adjacent layers with the fault has moved downward relative to different wavelengths and shape the block below. This type of faulting occurs in response to extension. MODULE 8 Occurs when the “hanging wall” moves down relative to the “foot wall” FAULTS IN ROCKS REVERSE FAULT FAULT A fault is a fracture or zone of fractures between two blocks of rock. Faults are fractures along which the opposite sides have moved relative to one another and parallel to the fracture surface. Reverse faults form when the hanging wall There are five active fault lines in the moves up. country namely the Western Philippine The forces creating reverse faults are Fault, the Eastern Philippine Fault, the compressional, pushing the sides. South of Mindanao Fault, Central THRUST FAULT Philippine Fault and the Marikina/Valley Fault System. TYPES OF FAULT DIP-SLIP FAULTS Dip-slip faults are inclined fractures where A thrust fault is a break in the Earth's crust, the blocks have mostly shifted vertically. across which older rocks are pushed Dip-slip faults are categorized as normal or above younger rocks. reverse. Normal: If the rock mass above an inclined TRANSCURRENT OR STRIKE-SLIP FAULTS fault moves down. A fault on which the two blocks slide past Reverse: if the rock above the fault moves one another. up There are two types of strike-slip faults: A Three different types of dip-slip faults are left-lateral and right-lateral strike-slip normal, reverse and thrust fault. fault. NORMAL FAULT LEFT-LATERAL STRIKE-SLIP FAULT A dip-slip fault in which the block above 15 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY MYLONITE Rock with fine-grained, cohesive, aligned minerals caused by shearing PSEUDOTACHYLYTE A ultrafine-grained glassy-looking fault rock formed by the frictional melting and Is a type of strike-slip fault where the left rapid solidification of rocks during block moves toward you and the right seismic faulting block moves away. RIGHT-LATERAL STRIKE-SLIP FAULT MODULE 9 SEA-FLOOR SPREADING PLATE BOUNDARIES: DIVERGENT BOUNDARY Occurs along the crest of oceanic ridges. Is a type of strike-slip fault where the right Magma upwells through cracks in the block moves toward you and the left block crust. moves away. Upwelling magma causes plates to move apart. OBLIQUE-SLIP FAULTS Results in the creation of new seafloor. SEA-FLOOR SPREADING Sea floor spreading is a geologic process in which tectonic plates –large slabs of Earth’s lithosphere-split apart from each other. HEAT TRANSFER VIA CONVECTION Oblique-slip faults have both strike-slip CURRENTS and dip-slip components of movement. Heat from molten materials from the mantle FAULT ROCKS and core is released towards the lithosphere through convection current. Rocks formed or altered along fault zones Convection currents cause seafloor due to tectonic movements. spreading. MAIN TYPES OF FAULT ROCKS Process explained by Harry Hess in 1960. Materials formed in the lithosphere are recycled back into the mantle. CATACLASITES Seafloor spreading involves the formation, Cohesive, crushed and fragmented rock lateral spreading, and subduction of resulting from faulting. mid-oceanic ridges. 16 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY SEAFLOOR SPREADING PROCESS OCEAN BASIN Molten materials rise, causing sideways spreading of the seafloor. WHAT IS OCEAN BASIN? Motion pulls the seafloor above. Regions below sea level containing about Mid-ocean ridge is created, serving as an 70% of Earth's water. outlet for molten materials. Results of tectonic forces and processes Outpouring of molten materials forms new which are formed from volcanic rock that oceanic crust. was released from fissures located at the Continuation leads to the building of mid-oceanic ridges. oceanic ridges composed of volcanic Ocean basins can be identified as active or rocks. inactive. RIFT VALLEY FORMATION EXAMPLES A central valley that forms at the summit of Ex. Pacific Ocean: Largest and deepest oceanic ridges. ocean basin, Atlantic Ocean: Molten materials continuously flow out, Approximately half the size of the Pacific, pushing seafloor away. not as deep, etc. Seafloor moves towards trenches, which are depressions on the ocean floor. ACTIVE AND INACTIVE OCEAN BASIN Molten materials cool and become denser Active Basins: Constantly creating and near trenches. shaping new structures. Cooled materials sink back into the Earth, Inactive Basins: Slow surface changes, get heated, and melted again. primarily collecting sediment. Seafloor spreading and recycling process continues until disappearance into deep MEASURING OCEAN DEPTHS ocean trenches. Sonar: A device that determines the SEAFLOOR RECYCLING EVIDENCE distance of an object under water by recording echoes of sound waves. Records show the oldest seafloor is Bathymetry: measurements of ocean around 170 million years, younger than the depths and the charting of the shape or oldest land rocks (about 3 billion years). topography of the ocean floor. Proximity to oceanic ridge correlates with seafloor age; closer to the ridge, younger VARIOUS METHODS OF MEASURING OCEAN seafloor is found. DEPTHS Oldest known ocean floor is approximately 200 million years, suggesting destruction SOUNDING LINE through subduction at deep-sea trenches. Seafloor age supports sea-floor spreading; Weighted rope lowered overboard until it youngest crust at ridges, progressively touched the ocean bottom older away from ridges towards This old method is time-consuming and continents. inaccurate. ECHO SOUNDING (SONAR) MODULE 10 17 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Measures depth by emitting DEEP-OCEAN TRENCHES high-frequency sound and detecting the echo. Narrow, elongated depressions on the Process: Sound emitted from the ship's seafloor. source. Returning echo detected by a Often adjacent to volcanic island arcs receiver on the ship. with active volcanoes. Deeper water results in a longer time for Represent the deepest features of the the echo to return. seafloor. SATELLITE ALTIMETRY SEAMOUNTS AND VOLCANIC ISLANDS Profiles sea surface shape using radar Submerged volcanoes are seamounts. pulse travel time. Those rising above the ocean surface are Measures time from satellite to ocean volcanic islands. surface and back. Can be isolated, in clusters, or form Sea surface shape approximates seafloor chains. shape. FEATURES OF THE OCEAN MODULE 11 MOVEMENT OF PLATES MID-OCEAN RIDGE Submarine mountain chain spanning over TYPES OF GEOGRAPHIC FEATURES AT A 65,000 km globally. PLATE BOUNDARY Features a central rift valley and rugged flanks. PLATE TECTONICS THEORY Cut and offset by transform faults. Transform faults may extend as older, Formulated in the 1960s. seismically inactive fracture zones from Earth's crust fractured into at least a dozen either side of the ridge. distinct plates. Plate boundary is a fracture separating CONTINENTAL MARGIN plates. The submerged outer edge of the continent Plates move, interact, and form boundary where continental crust transitions into zones. oceanic crust. TYPES OF BOUNDARIES ACCORDING TO Has two types: Passive or Atlantic type THEIR MOVEMENTS and Active or Pacific type ABYSSAL PLAINS AND ABYSSAL HILLS CONVERGENT BOUNDARY Abyssal Plain: Extremely flat Occurs when two plates move toward sediment-covered ocean floor. Interrupted each other. by occasional mostly extinct volcanoes Crust is destroyed in the convergence. called seamounts. Heavier plate subducts beneath the more Abyssal Hills: Elongate hills, typically buoyant plate. 50-300m high. Common on the slopes of Convergent boundaries are subduction the mid-oceanic ridge. zones. 18 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Convergent Boundaries have three kinds:. Upwelling of magma from the mantle Oceanic-continental, Oceanic-oceanic, creates new seafloor (seafloor spreading). and Continental-continental Continental rifting, starting as a rift within a convergence. continent, can lead to volcanic activity, the formation of a rift valley, and, with OCEANIC-CONTINENTAL CONVERGENCE continued rifting, result in the development Forms trenches, destructive earthquakes, of an ocean basin and ridge system. and uplifts mountain ranges. Convective forces in molten magma cause Collision results in the subduction of the spreading, with fluid basalt lava filling the denser oceanic plate beneath the lighter gap and forming new oceanic crust. continental plate. Rift valleys form with continental plates, Geological outcomes: while Ridges form on the seafloor with - Continental plate lifted, creating oceanic plates. mountains. - Subduction forms a trench. TRANSFORM FAULT BOUNDARY - Descending plate melting leads to Occurs when plates slide horizontally volcanic activity on the continental past one another. plate. Most common in the ocean basin, with a few found in continental plates. OCEANIC-OCEANIC CONVERGENCE Affects active spreading ridges, creating Forms trenches (e.g., Mariana Trench) and zigzag plate margins. volcanic arcs. Defined by shallow earthquakes. Collision involves subduction of the older, Caused by variable rates of adjacent denser oceanic plate. plate travel, leading to lateral movement. Similar results to oceanic-continental Transform boundaries are neither convergence. destructive nor constructive, termed Undersea volcanic activity can lead to the conservative. formation of island chains. Common on the seafloor, forming oceanic CONTINENTAL-CONTINENTAL fracture zones. CONVERGENCE On land, they produce faults connecting offsetting divergent zones Forms mountain ranges like the Himalayas. GEOLOGICAL FEATURES Colliding continental plates are equally light, preventing subduction. FAULT LINES Intense pressure leads to buckling and slipping, both vertically and horizontally. Transform boundary connecting two Process creates the largest mountains on diverging boundaries, creating shear Earth. zones. DIVERGENT BOUNDARY EXAMPLE Occurs when two plates move away. San Andreas Fault connects the East Diverging plates move 2 to 5 cm per year. Pacific Rise to the South Gorda, Juan de Common along the crest of oceanic Fuca, and Explorer Ridges. ridges. TRENCHES 19 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Formed by convergent boundaries, where EXAMPLE heavier plates are forced downward, creating subduction zones. East African Rift Zone, a triple junction EXAMPLE involving the Arabian Plate, Nubian Plate, Marianas Trench formed by the and Somalian Plate. convergence of two oceanic plates, with the Challenger Deep over 36,000 feet deep. MODULE 12 VOLCANOES Result from subduction zones, where MECHANISMS THAT DRIVE THE MOVEMENT downward-forced plates melt, causing OF PLATES magma to rise and form volcanoes. Two converging oceanic plates can create THREE FORCES THAT PROPOSED AS THE island chains, e.g., Mariana Islands MAIN DRIVERS OF PLATE MOVEMENTS alongside the Marianas Trench. MANTLE CONVECTION CURRENT EXAMPLE Driven by heat, these currents carry Mount Saint Helens formed by oceanic lithospheric plates like items on a plate subducting under the North American conveyor belt. continental plate. RIDGE PUSH MOUNTAIN RANGES Newly-formed, warm oceanic plates at ridges have higher elevation, pushing Formed when two continental plates them away from the divergent boundary. converge, causing a powerful collision and intense pressure. SLAB PULL EXAMPLE Older, colder plates sink at subduction zones, pulling the rest of the plate behind Himalayas, a towering mountain range due to increased density as they cool. resulting from continental plate collision. MECHANISMS THAT DRIVE THE MOVEMENT RIDGES OF PLATES Formed at divergent boundaries where tectonic plates spread, feeding magma to CONVECTION CURRENTS the surface and creating new crust. Occur between the core and mantle or EXAMPLE asthenosphere and lithosphere. Mid-Atlantic Ridge, an oceanic divergent Asthenospheric currents act like conveyor boundary formation belts moving the overlying lithosphere. Hot rock rises, cools down, increases in RIFT VALLEYS density, and eventually sinks back to the Result from divergent boundaries in core. continental plates, forming depressions that may evolve into new ocean floors. 20 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Material density determines sinking or Bedding, Stratification, Lamination - rising; denser material sinks, less dense refers to layering that occurs in sedimentary material rises. rocks. Earth's plates move as the lithosphere Stratification - general term for layering in floats on the asthenosphere, leading to sedimentary rocks. lateral movement away from mid-ocean Beds - layering in sedimentary rocks, which ridges. are greater than 1 cm thick. Heat source: Radioactive materials in Lamination - layering in sedimentary rocks, Earth's core. which are less than 1 cm thick. SLAB PULL STRATIFICATION Denser plate sinking into the mantle. Layering in sedimentary and some Gravity pulls the rest of the plate. surface-formed igneous rocks. Associated features: subduction and Result of sedimentary deposition. trench. Changes in strata interpreted as fluctuations Subduction: One plate pulled into the in the intensity and persistence of the mantle, melted, and recycled. depositional agent, e.g., currents, wind, or waves, or in changes in the source of the RIDGE PUSH sediment. Gravitational forces act on young, raised Stratification planes: Planes of parting, or oceanic lithosphere. separation between individual rock layers. It Lithosphere slides down due to gravity. is horizontal or inclined, reflecting Raised by weaker asthenosphere, pushing depositional conditions. lithospheric material away from the ridge. Bottom surface conforms to underlying Rising mantle material creates the potential irregularities; upper plane tends to be for plates to move away from the ridge. nearly horizontal. Features associated: Mid-Ocean Ridge and Rift Valley. STRATIFICATION IN SEDIMENTARY ROCKS Varies in prominence and structure. MODULE 13 Best developed in fine-grained sediments. Least apparent and persistent in STRATIFIED ROCKS coarse-grained materials (e.g., conglomerates). Has two distinct types: Cross-bedding and STRATIGRAPHY Graded Bedding. Stratigraphy deals with the study of any CROSS-BEDDING layered (stratified) rock, but primarily with sedimentary rocks and their composition, Common in fluvial or aeolian deposits. origin, age relationships, and geographic Layering at an angle to the main bedding extent. plane. Stratum is a layer of sedimentary rock or Resulting structures include cross-beds or soil, or igneous rock that was formed at the sets. Earth's surface. GRADED BEDDING Systematic change in grain or clast size across the bed. 21 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Commonly exhibits normal grading from Sediment layers provide insights into the coarser at the base to finer upward. past environment. Geological events leave evidence in the STRATIFICATION IN VOLCANIC ROCKS stratified layers. Differs from sedimentary rocks. Fragmental volcanic material sorted during flight by gravity, particle size, and wind. Forms well-sorted layers upon settling on MODULE 14 the ground. RELATIVE AND ABSOLUTE DATING If deposited in lakes or the sea, it exhibits layering similar to waterborne detrital matter. RELATIVE DATIING Resultant stratification may occur from Determining how old something is successive lava flows or alternations compared to something else. between flows and ash falls. Use words like “older” or “younger” SEDIMENTARY ROCK FORMATION instead of exact numbers. Laid down in layers called beds or strata. DIFFERENT PRINCIPLES Bed defined as a layer with uniform lithology and texture. PRINCIPLE OF SUPERPOSITION Beds form through deposition of sediment layers. Sequence of beds is called bedding. Sedimentary rocks formed from sediments. SEDIMENTARY PROCESSES Weathering: Physical and chemical Based on the sequence of the sedimentary breakdown of rocks. rocks, the layers from the bottom is older Erosion: Removal of sediments from their and the successive higher layers to sources. younger rocks. Transport: Movement of sediments via water or wind. PRINCIPLE OF HORIZONTALITY Deposition: Settling of sediments due to decreased energy. Diagenesis: Lithification of sediments to form sedimentary rocks. Not all sedimentary deposits are stratified.. Original stratification may be disrupted by the deposited sedimentary rocks form various factors post-deposition. horizontal or nearly horizontal layers. CAUSES OF STRATIFICATION PRINCIPLE OF CROSS-CUTTING Stratified rocks formed by layers of sediments over time. Sedimentary rock exhibits visible banding patterns. 22 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Paraconformity: Absence of strata based on fossil assemblage, indicating non-deposition. ABSOLUTE DATING Placing the actual age of the rock. The geologic features like faults or igneous intrusions are younger than the UNSTABLE ISOTOPES rocks cut across To determine the actual age of the rock, scientists use unstable isotopes. PRINCIPLE OF INCLUSIONS Isotopes are elements that have same number of proton but different number of neutrons. The unstable isotopes are called radioactive isotopes or parent isotopes. DECAY The decay of the radioactive element over a long period of time is called half-life. If the rock fragments are included with Carbon-14 has half-life of 5730 years. another rock layer, the rock fragments RADIOMETRIC DATING must be older than the rock layer where they are embedded. Radiometric dating is a method used to determine the actual age of the rock using UNCONFORMITIES the decay of radioactive isotopes present represent the interruption in the process of in rocks and minerals. deposition of sedimentary rock The accuracy of radioactive dating can only be seen if the mineral containing the radioactive isotopes remained a closed system during the entire period since its formation. MODULE 15 SUBDIVISIONS OF GEOLOGIC TIME TYPES OF UNCONFORMITIES GEOLOGIC TIME SCALE Angular Unconformity: Tilted strata The history of the Earth is recorded in its overlain by more horizontal (younger strata). rocks. Disconformity: Erosive agents act on The Earth is approximately 4.6 billion rocks, forming evidence of minimal years old; basically, the same as the solar deposition. system Nonconformity: Igneous rocks cut through The Geologic Time Scale (GTS) is a layers or metamorphic rocks act as a base. hierarchical set of divisions describing geologic time. 23 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY ranging from the largest, eons, to the ORIGINS OF GEOLOGIC TIME SCALE smallest, ages. MINING ORIGINS Interest in geological relationships began with miners in the 1500s and 1600s. PHANEROZOIC EON Phanerozoic Eon: Represents the era JAMES HUTTON’S CONTRIBUTION (LATE when macroscopic organisms, including 1700S) algae, fungi, plants, and animals, lived. Studied sedimentary rocks, fossils, and Beginning: Initially thought to coincide with proposed the idea of deep geological time. the origin of life, it actually marks the NICOLAUS STENO (1669) appearance of animals with external skeletons and later those with internal Introduced principles that sedimentary skeletons. rocks are laid down horizontally, and Precambrian: The time before the younger rocks overlay older rocks. Phanerozoic, divided into three eons. PRINCIPLE OF UNIFORMITARIANISM PHANEROZOIC James Hutton's idea, emphasized by Phanerozoic subdivisions: Cenozoic, Charles Lyell, that natural geological Mesozoic, and Paleozoic Eras. processes are uniform over time. CENOZOIC WILLIAM SMITH’S CONTRIBUTION (1815) Recent era, often called the "Age of Produced a geologic map of England, Mammals," extending to the present. demonstrated the principle of faunal Major changes: Evolution of large succession using fossils to define time mammals, extinction of large reptiles, increments. continental drift, and the rise of human RELATIVE AND ABSOLUTE AGE DATING OF dominance. ROCKS MESOZOIC Scientists noticed in the 1700s and 1800s Known as the "Age of Dinosaurs," that similar layers of sedimentary rocks all featuring dinosaur evolution, the emergence over the world contain similar fossils. of mammals, and the transition of some They used relative dating to order the rock reptiles to mammals. layers from oldest to youngest. With the discovery of radioactivity in the PALEOZOIC late 1800s, scientists were able to measure Marked by a diversity explosion at the the exact age in years of different rocks. beginning, land colonization, insects Measuring the amounts of radioactive taking flight, and a mass extinction event elements in rocks let scientists use towards the end. absolute dating to give ages to each chunk Significant events: Land colonization, of time on the geologic time scale. insect flight, limestone formation, and the DIVISIONS OF THE GEOLOGIC TIME SCALE Devonian period as the "Age of Fishes." The geologic history of the Earth is DEVONIAN PERIOD organized into hierarchical time units, 24 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY Known for a variety of fish, including NOT all fossils are index fossils armored placoderms with bladelike jaws If geologists identify an index fossil in a rock layer, and diverse bone-plated fish forms. they can estimate when that rock layer was formed. PRECAMBRIAN ERA Meaning: "Before the Cambrian period." ORDERING OR ROCK LAYERS Also known as the Cryptozoic or "obscure Scientists read the rock layers knowing life" Eon. that each layer is deposited on top of other Covers almost 90% of Earth's history. layers. Divided into three eras: Hadean, Archean, The law of superposition states that each and Proterozoic. rock layer is older than the one above it. So, Originally defined as the era before the the relative age of the rock or fossil in the Cambrian; now known to have early life. rock or fossil in the rock is older if it is Archean and Proterozoic are the major farther down in the rock layers. subdivisions. Relative dating can be used only when the Rocks younger than 600 million years are rock layers have been preserved in their considered part of the Phanerozoic. original sequence. TO BE AN INDEX FOSSIL… MODULE 16 an organism must have lived only during a INDEX FOSSILS short part of Earth's history; many fossils of the organisms must be found in rock layers; FOSSILS the fossil must be found over a wide area of are the remains of plants or animals from Earth; the past, it could be a part, print, or trace. the organism must be unique. Latin word fossus, which means “having the shorter time period a species lived, the been dug up”. better an index it is. Index fossils (also called key fossils or type Fossils that are found in many rock layers, fossils) are those that are used to define therefore living long periods of time, do periods of geologic time. not qualify as index fossils. Major Fossil Groups: Corals, Bivalves, Fossils of widely distributed organisms that Brachiopods, Gastropods, Cephalopods, lived during only one short period time. Trilobites, Crinoids, and Plant Fossils. CONDITIONS REQUIRED TO PERMIT INDEX FOSSILS FOSSILIZATION Index fossils are marker fossils used to Rapid Burial – prevents the decomposition define periods of geologic time. of the remains. Index fossils are distinctive, widespread, Protective cover or medium – will prevent and have limited geologic time range. the attack of organisms living on dead Provide information about the age of rock organisms and will also prevent air and layers. moisture from building up. Must have lived for a relatively short Possession of hard part of durable period of time. tissues - bones, teeth, shells, and other Lived in many places around the world hard parts of an organism will most likely be 25 School Year 2024-2025 RCC AND SSLG: YOUR REVIEWING BUDDY preserved during fossilization. Soft tissues, Success and abundance make them organs, and flesh usually disintegrates. vulnerable to environmental change and extinction. MOST COMMON TYPES OF FOSSILIZATION Boom-and-bust characteristic makes them excellent index fossils. PRESERVATION WITHOUT ALTERATION TRILOBITES, HARD-SHELLED No major modification of the chemistry INVERTEBRATES occurs. Trilobites are excellent index fossils for EXAMPLES Paleozoic rocks, living in various oceanic regions. Frozen mammoths, elephants of Siberia, The trilobite class exhibited constant and Alaska. evolution of new species over their PRESERVATION WITH ALTERATION 270-million-year existence. Chemical composition of organic remains Ranged from the Middle Cambrian to the is altered. end of the Permian Period, covering almost the entire Paleozoic era. PETRIFICATION Mobile nature and hard shells contribute Replacement of porous woody material with to easy fossilization, and their fossils are minerals. large enough for study without a Forms a rock-like image (petrified) as silica microscope. replaces original wood components. SMALL OR MICROSCOPIC FOSSILS RECRYSTALLIZATION Major index fossils are small or Shells made from Aragonite recrystallize microscopic, part of oceanic plankton. into the more stable Calcite after the Their small size makes them useful, even organism's death.