Earth Process and Materials for first Sem.pptx

geology department

1. Earth’s Process By Ass.Prof. Abdul B ari Qanit Department of G eology & Mines

2. There two types of earth’s process, which are: Endogenic Process: (which take place in the sub-surface). a. Plate-Tectonic b. Volcanism 2. Exogenic Process: (which take place on the surface). a. Sedimentary Process/ Weathering

3. Plate Tectonic

4. The first formed ocean and continent Panthalassa super-ocean Pangea Super-continent 250 million years ago

5. Cimmeria Ocean Tethys Sea Breaking of Pangea

6. So the question is, how such things happened? Answer: Its because of Tectonic Movements!!!

7. What is Tectonic ?

8. Tectonic Or Plate-Tectonic is the Theory which Discovered by Alfred  Wegener (1912) and tells us about that the Earth's Crust is divided into several plates which move over the mantle .

9. Why the Plates Move ?

10. The Plates Move because there are some Forces in the Earth’s Interior which Drives them and Push them to Move.

11. Plate Driving Forces Thermal Convection in the Mantle. (95%) The Slab-Pull Forces. (5%)

12. Why the Temperature and Pressure or Magma Rises Up from the Mantle ?

13. a. Asthenosphere which is highly viscous, physically weak and plastically deforming region of the upper mantle. b. Presence of Plumes or Convection Cells in the Asthenosphere. c. High degree of T & P in the Mantle. Thermal Convection from Mantle rise up to the Crust, is all because :

14. Tectonic Plates The lithosphere, which is the rigid outermost shell of a planet (the crust and upper mantle), is broken up into   Tectonic Plates. The Earth's lithosphere is composed of seven or eight major plates and many minor plates.

15. Major Plates Pacific Plate  – 103,300,000 km 2 North American Plate  – 75,900,000 km 2 Eurasian Plate  – 67,800,000 km 2 African Plate  – 61,300,000 km 2 Antarctic Plate  – 60,900,000 km 2 Australian Plate  – 47,000,000 km 2 Indian Plate  – 11,900,000 km 2 South American Plate  – 43,600,000 km 2

16. Minor Plates Somali Plate  – 16,700,000 km 2 Nazca Plate  – 15,600,000 km 2 Philippine Sea Plate  – 5,500,000 km 2 Arabian Plate  – 5,000,000 km 2 Caribbean Plate  – 3,300,000 km 2 Cocos Plate  – 2,900,000 km 2 Caroline Plate  – 1,700,000 km 2 Scotia Plate  – 1,600,000 km 2 Burma Plate  – 1,100,000 km 2 New Hebrides Plate  – 1,100,000 km 2

17. Plate Boundaries and Plates Movements

18. Plate Boundaries Plate Boundaries w here the plates meet. T heir relative motion determines the type of boundary, whether it is convergent , divergent, or  transform boundaries.   Earthquakes , volcanic activity, mountain-building, and  oceanic trench formation occur along these plate boundaries.

19. Where two plates collides to each other.

20. Active and Passive Plate Boundaries Active boundaries are those which still have the process of Volcanism, for example Pacific plate boundaries. Passive boundaries are those which are not having such process, like Indian plate boundaries.

21. Volcanism is mostly focused at plate margins Pacific Ring of Fire

22. Volcanos آتشفشانونه

23. What is a Volcano ?

24. » A volcano is a place where lava reaches the surface . » An opening in the earth's crust through which molten lava, ash, and gases can escape.

25. Causes of Volcanic activity Internal Heat Radioactivity Contraction of the earth’s surface Plate tectonics Rising magma through plumes.

26. Where the volcanoes likely to occur ? Where the Earth Crust is Weak. 2. Where active tectonic boundaries are exist.

27. Classification of Volcanos Activity : a. Explosive- Volcanos b. Effusive- volcanos Mode of Eruption : a. Fissure-volcano (have multiple channels) b. Central-volcano ( have single pipe) Frequency : a. Extinct- Volcanos b. Dormant-Volcanos c. Active-Volcanos 4. Form of Volcano : a. Shield volcano b. Cinder volcano c. Composite/Stratovolcano

28. Shield Volcano: A gently-sloped volcano.

29. Cinder Cone: A volcano made of cinders that are blown into the air.

30. Composite Volcano/stratovolcano A volcano built of alternating layers of cinders and lava. Composite volcanoes consist of lava that is mixed with sand or gravel which in turn creates cinders or volcanic ash .

31. Composite Volcano/stratovolcano

32. A volcano can build and destroy too. When the lava gets cooled, different types of rocks will be formed, such as basalt, diorite, granite, obsidian etc.

33. Exogenic Process

34. Weathering & Erosion

35. Weathering - فرسایش Physically disintegration and chemically decomposition of rocks is called as “Weathering”. And Erosion is the result of weathering + transportation

36. Erosion The process of eroding or being eroded by wind, water, or other natural agents.

37. Agents of Weathering عوامل فرسایش Temperature Water Ice ( glaciers ) Wind and Gravity.

38. Types of Weathering Physical Weathering Chemical Weathering Biological Weathering Breaking of rocks Erosion Deflation Abrasion Attrition Oxidation Reduction Carbonation Hydrolysis Organism’s activity

39. b. Abrasion : robbing the particles along with surface which gets break. c. Attrition : robbing the particles one with another and hence get break. Erosion Deflation : (L. deflare = To blow away). blow up the particles by strong wind.

40. Oxidation and Reduction Oxidation  is the loss of electrons or an increase in  oxidation  state by a molecule, atom, or ion.  Reduction  is the gain of electrons or a decrease in  oxidation  state by a molecule, atom, or ion.

41. The iron in olivine (Fe 2 SiO 4 )   is reduced and the iron in limonite (Fe 2 O 3 .H 2 O)  is oxidized. FeO(OH)

42. Carbonation

43. Hydrolysis or Hydrolysation Hydrolysis  is a chemical reaction caused by water. Water changes the chemical composition and size of minerals in rock, making them less resistant to weathering

44. Biological Weathering Plants Bacteria Animals Anthropogenic

45. Rocks ډبرې ، سنګها

46. Definition The aggregation of Minerals called as “Rock”. Such as: Pegmatite, Basalt, Granite etc.

47. Rocks are generally aggregation of minerals but there are some mono- mineralic (having only one mineral) rocks while most of the rocks are multi- mineralic , consisting more than one mineral as chemical constituent, such as pegmatite is a multi- mineralic rock.

48. Mono- mineralic Rocks Igneous rocks: Dunite – only olivine Pyroxenite – only augite Sedimentary rocks: Limestone – only calcite Sandstone – only quartz Metamorphic rocks: Marble – only calcite Quartzite – only quartz.

49. 1. Geologically Igneous rocks – form from magma . Metamorphic rocks - forms as rocks are heated and squeezed. Sedimentary rocks – forms as smaller pieces or chemicals from other rocks get together.

50. 2. physically Stratified Rock: show distinct layers along which the rock can be split. For example, shale, sandstone, limestone, marble, slate, etc. Unstratified Rocks: do not show any stratification and can be easily split into thin layers. Such as granite, basalt, etc. Foliated Rocks: have tendency to split up only in a definite direction. Most of the metamorphic rocks have a foliated structure, except for quartzite and marble which have granular structure.

51. 3. Chemically Argillaceous Rocks: The principle constituent is clay (Al 2 O 3 ). The rocks are hard and brittle. Such as Slate and Laterite. Siliceous Rocks: The Principle constituent is Silica (SiO 2 ). Sand, Basalt, granite, quartzite, Gneiss, etc. Calcareous Rocks: The principle constituent is Lime (CaCO 3 ). Such as Limestone, marble and dolomite.

52. Igneous Rocks ناریه – اور ډبری

53. Igneous Rocks Igneous rocks which are formed from Magma and Lava. Magma: The Molten Materials below the earth’s surface. Lava: magma which erupted to the earth’s surface.

54. Formation of Igneous Rocks Magma Eruption Differentiation Cooling & Crystallization Increase of Heat & Pressure Decrease of Heat & Pressure

55. Formation of Igneous Rocks

56. Crystallization Crystallization  is the way that atoms gather to make tightly bonded or connected groups. It separates a solid from a liquid or sometimes from a gas.

57. Igneous rocks are divided as: Plutonic (or) Intrusive Rocks: Are those which are formed in Great Depth, and they are Coarse Grained rock. Such as Granite and pegmatite. Volcanic (or) Extrusive Rocks: Are those which formed on the surface of earth, and they are Fine Grained rock. Such as Basalt and Rhyolite. Hypabyssal Rocks: Are those which are formed near to the Surface of the earth, and they Fine or Medium Grained rocks. Such as Diorite and Quartz- dolorite .

58. Granite Rock

59. Pegmatite rock

60. Basalt Rock

61. Rhyolite rock

62. Sedimentary Rocks رسوبي ډبری

63. Sedimentary rocks Rock  that has formed through the deposition and solidification of sediment, especially sediment transported by water (rivers, lakes, and oceans), ice ( glaciers ), and wind.  Sedimentary rocks  are often deposited in layers, and frequently contain fossils. Sandstone, Limestone and shale are common  sedimentary rocks .

64. Formation of Sedimentary Rocks Pre-existing Rocks Weathering / Erosion Transportation Accumulation Digenesis & Lithification Compaction Cementation Bacterial Action or Chemical Replacement

65. Making of Sedimentary Rocks

66. Generally the sedimentary rocks formed in three ways: Mechanically Chemically Organically Conglomerate

67. Evaporation

68. Sandstone

69. Metamorphic Rocks متحوله ډبری

70. Metamorphic Rocks Rocks which formed due to the Process of Metamorphism. Such as Quartzite and Gneiss. Metamorphism: Alteration of the composition or structure of a rock by heat and pressure .

71. Metamorphic rocks form from the alteration, transformation and rearrangement of the pre-existing sedimentary and igneous rocks, such as:

72. Metamorphic rocks are generally in two types Foliated Non-foliated Schist rock Quartzite rock

73. The Rock Cycle

74. It Means that: All the rocks can be transformed into Each other rock types.

75. Minerals منرالونه

76. Earth Rocks Igneous Metamorphic Sedimentary Mineral/Minerals Element/Elements

77. What is an ELEMENT? A substance composed of a single kind of atom . Cannot be broken down into another substance by chemical or physical means.

78. Mineral A naturally occurring, organic and inorganic homogeneous substance, with almost fixed chemical composition and majority of them have definite internal atomic structure.

79. For Example: Quartz , Emerald , Diamond , Hematite , Magnetite, Tourmaline , Calcite , Ruby , Olivine etc.

80. Emerald زمرود

81. Ruby - یاقوت

82. Sapphire - سفایر