Earth Materials and Processes : ENDOGENIC PROCESS
- 1. Chapter 5: Earth Materials and Processes ENDOGENIC PROCESS
- 2. •Processes that is formed or occurring beneath the surface of the Earth. ENDOGENIC PROCESS
- 3. a mixture of molten rock, minerals and gases. This mixture is usually made up of a hot liquid base called the melt, minerals crystallized by the melt, solid rocks incorporated into the melt from the surrounding confines and dissolved gases. MAGMA
- 4. originates in the lower part of the Earth’s crust and in the upper portion of the mantle known as asthenosphere. MAGMA
- 7. • At about 30 to 65 km below the earth’s surface, the temperature is high enough to melt rocks into magma. The reason why it is difficult to drill holes deep into the crust is that the temperature rises about 30 degree for every kilometer. • The asthenosphere which is between 100 to 350km deep is so hot that most of the rock is melted . The melt flows very slowly because it is under intense pressure. Magma reaches temperatures between 600 degree 140 degree Celsius. How Are Magmas Formed ?
- 9. • Deep in the Earth, nearly all magmas contain gas dissolved in the liquid, As magma rises at the surface of the Earth, pressure is decreased and the gas forms a separate vapor phase. This is somewhat similar to carbonated beverages which are bottled at high pressure. • When magma emerges on the surface of the Earth, it is called lava. Lava spilling over or erupting from craters is usually bubbly, a sign that gases are escaping. Gases in Magma
- 10. •Viscosity is the resistance to flow (an antonym for fluidity). • Magma with higher silica content has higher viscosity. Viscosity increases with increasing silica concentration in the magma. • Magma with low temperature has higher viscosity than those with high temperature. Viscosity decreases with increasing temperature of the magma. Viscosity of Magmas
- 11. • Magma leaves the confines of the asthenosphere and crust in two major ways; an intrusion or extrusion. • Magma can intruded into low-density area of another geologic form such as a sedimentary rock. When it cools and hardens, this intrusion develops into an pluton commonly know as an igneous intrusive rock. • Magma rises towards the Earth`s surface where are less dense surrounding rocks and when a structural zone allows movement. Magma Escape Routes
- 15. • Magma develops within the upper mantle and crust where the crust where the temperature and pressure conditions favor the molten state. Magma collects in areas called magma chamber. • There pool of magma in a magma chamber is layered. The least dense magma rises to the top. The densest magma sinks at the bottom of the chamber. • During an eruption, gases, ash and light-colored rocks are emitted from the least dense top layer magma chamber. Dark, dense volcanic rock from the lower part of chamber may be released later. Magma Chamber
- 16. 1. Decompression Melting 2. Transfer of Heat 3. Flux Melting Ways to Generate Magma
- 17. 1) Decompression Melting Ways to Generate Magma involves the upward movement of the Earth’s mostly solid mantle this hot material rises to an area of lower pressure through the process of convection.
- 19. 2) Transfer of Heat Ways to Generate Magma Happens when hot, liquid rock intrudes into the Earth’s crust. As the liquid rock solidifies, it loses this heat and transfers it to the surrounding crust. This is similar to a hot fudge poured over cold ice cream.
- 21. 3) Flux Melting Ways to Generate Magma It occurs when water or carbon dioxide added on rocks these affects the melting point of rock when added with water beneath the earth it generates magma.
- 23. Types of Magma 1. Felsic Magma 2. Intermediate Magma 3. Mafic Magma 4. Ultramafic Magma
- 25. This type of magma has viscosity level there has low in iron but high in potassium and sodium this form makes granite rocks. Felsic Magma
- 26. This normally found in volcano that erupts, after the eruption it releases a lava that has high silica and very viscous/ it commonly produced Andesite Rock. Intermediate Magma
- 27. Mafic magma has relatively low silica content but high in iron and magnesium. This magma has a low gas content and low viscosity. Mafic magma has high average temperature which contributes to its low velocity. Low velocity means that mafic magma is the most fluid of all magma types. Mafic Magma
- 29. Today our planet is to cool, for ultramafic magma to form. This is a probably a good thing, since ultramafic magma would be the hottest and fastest flowing magma. Ultramafic Magma
- 33. 1) Stress Rock Deformation the force that could create deformation on rocks in their shape and/ volume. Great forces from several directions may act on the lithospheric plates causing them to move. Although this crustal plates are elastic solid, they are subjected to great forces such as pulling, pushing or squeezing.
- 34. 1) Lithostatic stress Rock beneath the Earth’s surface experiences equal pressure exerted on it from all directions because the weight of the overlying rock. It is like the hydrostatic stress (water pressure) that a person feels pressing all over his body when diving down deep in the water. Kinds of Stress
- 35. 2) Differential stress stress on rocks that are caused by an additional due to unequal stress due to tectonic forces. 3 Kinds are a) Tensional stress (stretching) b) Compressional stress (squeezing) c) Shear stress Kinds of Stress
- 36. a) Tensional stress (stretching). This is when rock is stretched apart or pulled apart. Where crustal plates diverge, rocks are pulled apart. b) Compressional stress (squeezing). This is when rock is pressed, squeezed or pushed together . It’s like a car caught in the middle of a long pile up on the highway. Where crustal plates collide, rocks are compressed or pushed. c) Shear stress which results in slippage and translation. With shear stress, the rock is being pulled in opposite directions. It is similar to the motion between individual playing cards when the top of the stack is moved relative to the bottom. Types of Differential Stress
- 37. 2) Strain Rock Deformation ability of a rock material to handle stress depends on the elasticity of the rock.
- 38. a) Elastic deformation For small differential stresses, less than the yield strength, rock deforms like a spring. It changes in shape by a very small amount in response to the stress. The deformation is not permanent. This deformation is reversable. The rock can return to its original shape. b) Brittle deformation or Fracture Near the Earth’s surface rock behave in its familiar brittle fashion. If a differential stress is applied that is greater than the rock’s yield strength, the rock fractures. Fracture is an is an irreversable strain wherein the rock breaks. Types of Deformation
- 39. 3) Joints Rock Deformation fractures in rocks that show little or no movement at all.
- 40. 4) Faults Rock Deformation are extremely long and deep break or large crack in a rock a result of continuous pulling and pushing.
- 41. a) Dip-slip fault (Normal fault) b) Strike-slip fault c) Reverse (or thrust) fault Types of Faults
- 42. 1) Dip-slip fault (Normal fault) occurs when brittle rocks are stretched-tectonic tensional forces are involved and the movement of blocks or rock is mainly in the vertical direction (sinking and rising). For dip-slip faults, the block lying on the top of the fault surface is referred to as the hanging wall while the one below is referred to as the footwall. Normal fault tends to dip about 600. The hanging wall has moved downward relative to the footwall. Types of Faults
- 43. Normal faults are the chief structural components of many sedimentary rift basins like the North Sea where they have major significance for hydrocarbon exploration.
- 45. 2) Strike-slip fault occurs when brittle rocks are sheared (the opposing tectonic forces are at right angles to compression and tension directions) and the movement of blocks of rock is chiefly in the horizontal direction. If the far side of the fault moves to the left relative to an observer it is called “sinistral strike- slip fault” (left-lateral). Types of Faults
- 47. 3) Reverse (or thrust) fault occur when brittle rocks are pushed (the tectonic forces are compressional). Types of Faults
- 50. Philippines has many faults. One of this is the Marikina Valley Fault System that contains two major segments: the West Valley Fault and the East Valley Fault. The West Valley Fault which is believed to impact as the BIG ONE is a dominantly strike-slip fault that extends from Dingalan, Aurora in the North and runs through the provinces of Nueva Ecija, Bulacan (Dona Rosario Trinidad, Norzagaray, San Jose del Monte), Rodriguez, Rizal and the cities of Metro Manila which include Quezon City, Marikina, Pasig, Makati, Parañaque, Taguig and Muntinlupa and the provinces of Laguna (San Pedro, Biñan, Sta. Rosa, Cabuyao, Calamba) and Cavite (Carmona, Gen. Mariano Alvarez, Silang) that ends in Tagaytay. The eastern segment known as the East Valley Fault moves in an oblique dextral motion. It affects the area of Rodriguez and San Mateo Rizal.
- 51. Deformation Rocks buried deep within the Earth’s crust behave differently when subjected to differential stress. It is impossible to produce fracture in rocks the way it is at the Earth’s surface. Rocks become thicker under compressional stress and thinner under tensional stress. Rock layers tend to bend and go out of shape. The high temperature condition makes a rock softer, less brittle and more ductile.
- 53. FOLDS promoted by high temperature and pressure at great depth. When rocks deform in a ductile manner, instead of fracturing to form faults or joints, they may bend or fold and the resulting structures are called folds. Kinds of folds: 1. Monoclines 2. Synclines 3. Anticlines
- 54. 1) Monocline are the simplest types of folds. Monoclines occur when the horizontal layers are bent upward so that two limbs of the fold are still horizontal. Kinds of Folds
- 55. 2) Syncline are folds structures when the original rock layers have been folded downward and the two limbs of the fold dip inward toward the hinge of the fold. Kinds of Folds
- 56. 3) Anticline are fold structures formed when the originally rock layers have been folded upward and the two limbs of the fold dip away from the hinge of the fold. Kinds of Folds
- 57. Synclines and anticlines usually occur together such that the limb of a syncline is also the limb of an anticline. The anticline may form mountains, hills or ridges while the syncline may from valleys. Faults and folds are geological structure that result from the response of rocks to tectonic stresses induced by plate movements.
- 59. REFERENCE: • Moncada, M. et. al (2016). Earth and Life Science for Senior High School. Disclaimer: The pictures used in this slideshow presentation were obtained from various internet websites and will be only used for educational purposes only.