Earth Science Reviewer - 2nd Quarter - PDF

REVIEWER EARTH SCIENCE- QUIZ BEE LESSON: EXOGENIC PROCESS LESSON: EARTH’s INTERNAL HEAT EXOGENIC PROCESS What is Heat Energy? -The processes that occur at the earth’s surface due to - is a result of the movement of...

REVIEWER EARTH SCIENCE- QUIZ BEE LESSON: EXOGENIC PROCESS LESSON: EARTH’s INTERNAL HEAT EXOGENIC PROCESS What is Heat Energy? -The processes that occur at the earth’s surface due to - is a result of the movement of tiny particles called the influence of exogenic forces. atoms, molecules, or ions in solids liquids, and gases. Weathering, erosion, mass wasting, and deposition are -Plays a vital role in our planet. It is one of the extreme the main exogenic forces. factors that makes the world habitable. Weathering What are sources of heat? -is the process of disintegration (physical) and Primordial Heat and Radiogenic Heat decomposition (chemical) of rocks. Primordial Heat - is a process of breaking down rocks into small particles - is the internal heat energy accumulated by such as sand, gravel, and other fragments dissipation in a planet during its first few million years of evolution. Types of weathering Accretional energy- the inevitable result of gravitational A. Physical or Mechanical Weathering forces operating on all scales, and on all types of -is the breakdown of rocks into pieces without material — gas, dust, plasma, and even dark matter. any change in its composition. In this process, the size and shape of rocks changes and this Gravity makes matter accrete. occurs because of the following factors: Radiogenic Heat - is the thermal energy released as a result of the B. Chemical Weathering spontaneous nuclear disintegration of natural -is the weakening and subsequent disintegration radioactive elements inside the planet; Uranium, of rock by chemical reactions. These reactions Thorium and Potassium. include dissolution, hydrolysis and oxidation. Heat Transfer These processes either form or destroy minerals, CONDUCTION, CONVECTION and RADIATION thus altering the nature of the rock's mineral 1. Conduction- -governs the thermal conditions in composition. almost entire solid portions of the Earth.(upper part of C. Biological Weathering the earth or the crust. is a process when living things, such as insects 2.Convection -dominates the thermal conditions in the and roots of the trees, contribute to the zones where large quantities of fluids (molten rocks) disintegration of rock materials. exist. For example, mosses and fungi that grow on SUBDUCTION rocks produce weak acids that can destroy or -is the process by which the collision of the dissolve the rocks. earth’s crustal plates results in one plate being drawn down or overridden by another. Processes/ factors that bring about biological 3. Radiation-the process of heat exchange between the weathering Sun and the Earth. 1. Root Wedging 2. Burrowing of Animals 3. Anthropogenic Activities EROSION - Erosion is the separation and removal of weathered rocks due to different agents like water, wind, and glacier that causes transportation of the material to where they are deposited. - The movement of sediments downslope under the influence of gravity is called MASS WASTING. The example of this are fall, slide, avalanche and flow. DEPOSITION - is the geological process in which the weathered LESSON: ENDOGENIC PROCESSES materials carried out by erosion settle down in a ENDOGENIC PROCESSES particular location. -is a geological process that was formed, originated, and located below the surface of the earth. It involves geologic activities like tectonic movements, metamorphism, seismic activities, and magmatism. What is Magma? the pressure is reduced, and the rock can pass to the - Magma is composed of semi-liquid hot molten rocks liquid side of its melting curve. At this point, partial located beneath the Earth, specifically in the melted melting starts to take place. mantle rock and oceanic plate. This molten state, when solidified, creates igneous rocks found on the surface of Addition of Volatiles the Earth. Flux Melting – adding impurities like water and gas to lower the melting point of rocks. Magmatism is a process under the earth’s crust where What happens after magma is formed? the formation and movement of magma occur. So where do these formations and movements take place? Magma escaped in two forms: intrusion and extrusion. These happen in the lower part of the Earth’s crust and in the upper portion of the mantle, known as the Intrusion asthenosphere. -is magma that moves up into a volcano without erupting. What is meant by the intrusion of magma is Substances/Elements present in Magma. the inclusion of the rock layers forming the earth's crust (magma does not get out). Plutonism -Plutonism refers to all sorts of igneous geological activities taking place below the Earth's surface. -The solidification and crystallization of magma take place mainly inside the Earth's interior. -When the process of crystallization takes place inside the crust, the magnetic rocks produced are called plutonites, which is another major category of igneous rock formation. Extrusion How is Magma formed? -is an eruption of magmatic materials that causes land Partial Melting formation on the surface of the Earth. Magma that - Different minerals in rock melt at different came out to the surface of the earth is called an temperatures and pressure. eruption. The magma that came to the surface of the - Occurs in the lower crust and upper mantle earth is called lava. This figure shows how minerals in rocks undergo Magma can move up because of the high pressure partial melting. exerted by magma and gases. In the lithosphere, magma occupies a bag which is called a magma chamber. The depth of the magma chamber causes differences in the strength of volcanic eruptions. In general, the deeper the magma chamber, the stronger the explosion. Volcanism -Volcanism is used to describe all geological phenomena that occur on the natural terrestrial surface, such as the 3 Conditions for Melting the Rocks creation of volcanoes and hot springs. Melting in the mantle requires one of three possible -Molten material in the form of lava that undergoes the events to occur: process of crystallization on the natural terrestrial 1. Increase in temperature surface gives birth to rock formations known as 2. Decrease in pressure volcanites. These are one of the major categories of 3. Addition of volatiles igneous rock formations. An Increase in Temperature Metamorphism - Change that takes place within a body of rock as a result of it being subjected to conditions, that are different from those in which it is formed. In Metamorphism, rocks do not actually melt. They Decrease in Pressure (Decompression Melting) become denser and more compact. Minerals may also be changed or rearranged due to -Rocks beneath the earth remain solid when exposed to chemical reactions involving fluids entering rocks. high pressure. -During convection, if a rock that is hot enough to be close to its melting point is moved toward the surface, LESSON: Rock Behaviors Under Stress relatively younger than the oldest rock found on land. 3 main types of stress tension, compression, and shear. The following are three evidences that support the 1. Tensional stress causes rocks to be pulled apart that idea that seafloor is continuously spreading. result to lengthening and break apart. This type of stress (a.) Evidence from molten materials- rocks shaped like can be found at divergent plate boundaries. pillows (rock pillows) show that molten materials have 2. Compressional stress causes rocks to fold or fracture. erupted again and again from cracks along the It squeezes rocks together. Compression are the most midocean ridge and cooled quickly. common type of stress in convergent plate boundaries. (b.) Evidence from magnetic strip- rocks that make up 3. Shear stress happens when forces slide pass each the ocean floor lie in a pattern of magnetized stripes other in opposite direction which results to slippage and which hold a record of the reversals in magnetic field translation. This is the most common stress found in Magnetic reversal - supports the theory of seafloor transform plate boundaries. compression spreading (c.) Evidence from drilling sample – core samples from the ocean floor show that older rocks are found farther from the ridge; youngest rocks are in the midocean ridge. shear Scientists discovered that rocks farther away from the tension mid-ocean ridge are older than those near it by using Geologic Structures geologic dating techniques to determine the age of the 1. Folds – are formed when rocks experienced rocks samples obtained by drilling on the sea floor. compressive stress and deformed plastically. It causes bending of rocks. There are Before the use of echo sounders, scientists thought the three types of folds: monoclines, anticlines and ocean floor was flat and featureless, like a dumping synclines. Monocline is a simple bend in the rock layers ground for sediments from land. where the oldest rocks are at the bottom and the youngest are at the top. An anticline is a fold that arches LESSON: Structure and Evolution of Ocean Basins upward where the oldest rocks are found at the center Pacific Ocean basin is the largest, deepest, and oldest of an anticline. existing ocean basin. More trenches, and more frequent The youngest rocks are covered over them at the top of tsunamis happens here. It has been shaped by the structure.A syncline is a fold that bends downward plate tectonics. The second largest ocean basin is the which rocks are curved down to a center. Atlantic followed by the Indian ocean basin. The smallest of the earth’s ocean basins is Arctic, and is covered by ice. Formation of ocean basins, different features and structures 2. Faults - A rock under ample stress can crack, or 1. Continental shelf- Partly shallow extension of the fracture. The fracture is called a joint because there is a continent underwater. block of rock left standing on either side of a fracture 2. Continental slope- Transition zone of continental line.The footwall is the rock that place on top the fault, shelf and deep ocean floor. It starts from oceanic crust while thehanging wall is below the fault. to continental crust. 3. Continental rise- It where the ocean actually begins. All basaltic and oceanic rocks are found here. It is the LESSON: Seafloor Spreading place where the sediments from land are washed. The continental margin starts from continental shelf up In 1960, the American geophysicist, Harry Hess to continental rise. explained how the convection currents in the Earth’s 4. Abyssal plain- The flattest part of the ocean. 50 % of interior make the seafloor spread. Convection current the earth’s surface is being covered by this plain. carry heat from the molten materials in the mantle and 5. Island- It’s not just a piece of land floating up in the core towards the lithosphere. These current ensures middle of the sea, it is part of the ocean basin that that the “recycled” materials formed in the lithosphere extends up from the ocean floor. were back to the mantle. In this recycling process which 6. Seamount- It is an undersea mountain. The erosion was later named as seafloor spreading the magma caused by waves destroyed the top of a seamount which moves up from the mantle and erupts as pillow lava. caused it to be flattened. This forms new oceanic crust at the ridge. Then, as new 7. Trench- It is the deepest part of the ocean. oceanic crust form, it pushes the older crust aside. This 8. Mid-oceanic ridge- The seafloor mountain system means that the nearer the ocean floor to the oceanic which is situated in the middle of the ocean basin. It is ridge, the younger it is compared to the ones farther where upwelling of magma happens which causes from the ridge. This crust eventually subducts at the the sea floor to spread. deep ocean trenches and melts back into the mantle. Then the seafloor spreading continues as a “recycling” process. Record shows that the oldest seafloor is  3.Transform plate boundaries are where plates slide passed each other. The relative motion is horizontal. It can occur underwater or on land. In the process the crust is neither destroyed nor created. Due to this friction, the plates cannot simply glide past each other. As a result, stress builds up in both plates. When it surpasses the threshold of the rocks, energy is released which can cause earthquakes. LESSON: How Layers of Rocks (Stratified Rocks) Are Formed Rocks form layers due to sediments deposited on rocks Evolution of the Ocean Basin or some forces that act on them which causes their deformation. LESSON: Movement of Plates Stratigraphy The tectonic movement of the Earth's plates has rose in -a branch of geology that deals with the description, the folding and faulting of the crust. This is due to the correlation, and interpretation of stratified sediments & Earth's plates transversing, diverging or converging stratified rocks on & within the Earth. against one another. This causes the crust of the Earth -a study of rock layers. to clasp and be stressed, which can generate huge What are Stratified Rocks? amounts of pressure that build up as time progresses. Stratified Rocks- (layers of rocks) Most geologic motion stems from the interaction where -Rock derivatives (fragmental or crystalline) the plates meet or divide. Each tectonic plate is can -Product of sedimentary process that formed layers. move independently and freely floating. The plates move at a rate of one to two inches per year. This is due to the convection currents in the mantle of the Earth. The motion of plates can be described in four patterns. This includes collision wherein two continental plates are moved toward each other. Subduction when one plate subsides beneath the other plate. Another movement is spreading which occurs when two plates Stratification or bedding are move away from each other. Transform faulting - is the process leading to the formation or deposition of occur when two plates slide past each other. These layers, especially of the sedimentary rocks formed at the movements of the plates create three types of tectonic surface of the earth that come from lava flows or other boundaries which also explain the formation of folds, volcanic activity. faults, trenches, volcanoes, rift valleys, and mountain Nicolas Steno ranges. -a Danish Scientist studied the relative position of sedimentary rocks. Types of boundaries -He made the Stratigraphic laws of the rock layers. 1. Convergent plate boundary occurs when two plates collide. Subduction zones occur when one or both of Stratigraphic Laws the tectonic plates are composed of oceanic crust. The -are used by geologists in conducting relationships or denser plate is subducted underneath the less dense rocks or rock layers. plate. The plate being forced under is eventually melted and destroyed. When oceanic crust meets ocean crust 2.Divergent plate boundaries occur when two plates move away from each other. The space created will be filled with new material from molten magma that forms below the surface of the earth. Divergent boundaries can form within continents but may eventually open up and become ocean basins. Within continents this plate boundary initially produces rifts or rift valleys. The most active divergent plate boundaries are between oceanic plates which is called mid-oceanic ridges. This is also known as underwater mountain range. Law of Superposition - which states that, in any deposition, or b) by the erosion of depositionally undisturbed sequence of rocks deposited in layers, the continuous strata followed by renewed deposition. youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it. -the oldest layer is at the base and that the layers are progressively younger with ascending order in the sequence. The law or principle of cross-cutting relationships states that any geologic feature or rock body that cuts across or deforms another is the younger of the two. Methods of Correlating Rocks 1. Rock Types & its characteristic 2. Index fossil 3. Bedrock Law or principle of inclusions states that a rock containing another rock fragment is younger than the rock fragment or inclusion it encloses. For instance, a sandstone with granite fragments inside is younger than the adjacent granite. LESSON: Different Methods of Determining the Age of Stratified Rocks -rock layers are laterally continuous and may be broken up or displaced by later events. This can happen when a What is Relative Dating river or stream erodes a portion of the rock layers. This Relative dating is the technique used to determine the can also happen when faulting occurs. age by comparing the historical remaining to the nearby layers. -is the process of comparing and correlating rock layers to determine the relative age of rocks. Methods used in relative dating 1. Stratigraphy: This technique assumes that the lowest layer is the oldest while the topmost layer is the youngest layer. It is one of the oldest methods of An unconformity is a surface between successive strata relative dating. that represents a missing interval in the geologic record 2. Biostratigraphy: In this technique, the faunal of time, and produced either by: a) an interruption in deposits such as fossils of dead animals are used to establish a strategy for dating. It is an extended version of the stratigraphy. 3. Cross dating: In this method, the fossils of one layer are compared with another layer with known dating. 4. Fluorine dating: Bones from fossils absorb fluorine from the groundwater. The amount of fluorine absorbed indicates how long the fossil has been buried in the sediments. What is Absolute Dating In geology, absolute dating is a technique that determines the exact numerical age of a historical remaining. Since it evaluates the exact age of the sample, absolute ageing is also called numerical dating. - is the process of determining the age of materials like rocks and fossils or rock Layers. It uses radioactive isotopes(radioactive decay & half-life principles) to identify the exact age of the materials Four techniques used in absolute dating 1. Radiometric dating: It determines the age of the sample by measuring the amount of a particular radioactive isotope present in the sample. The age can be determined by the rate of decay of that particular isotope. The type of radioactive isotope used depends Geologic Time Scale on the type of sample. One of the most popular and widely used types of radioactive isotope in this type of -serves as the calendar for events in Earth’s history. techniques is the carbon-14. - Serves as a standard timeline used to describe the age 2. Amino acid dating: The change in the protein content of rocks, fossils & the events that formed them. of a biological sample can be used to determine the age. A particular form of a living being may have a defined protein content in their bodies that deteriorates with time. 3. Dendrochronology: The number of annual growth rings of a dicot is used in this technique to determine the age of the tree. 4. Thermoluminescence: This technique determines the final period during which the object absorbs light, emitting electrons. The age is determined with respect to the emissions 3 ERAS PALEOZOIC -beginning of early life -PANGEA existed - Terrestrial plants MESOZOIC - age of dinosour -break PANGAEA into Laurasia & Gondwana CENOZOIC - age of mammals - this is the era where human exist and still exist