Lesson 1: Geology

• Geology


  The study of Earth
• Engineering Geology


  The application of geology for a safe, stable and economic design and construction of a civil engineering project
• Branches of Geology

  • Physical Geology
  • Crystallography
  • Mineralogy
  • Petrology
• Physical Geology


  • Deals with the various agents that modify the face of the Earth
  • Includes the study of Erosion, Transportation and Deposition (ETD)
  • Plays a vital role in collecting a suitable basis for different types of foundations and in the study of the effects of the earth's processes on civil engineering structures
• Crystallography


  • Deals with the study of crystals
  • Not much important to civil engineering, but necessary to recognize the minerals
• Mineralogy


  • Deals with the study of minerals
  • Most important for a civil engineering student to identify the rocks
  • Important in industries such as cement, iron and steel, fertilizers, glass industry and in the production of atomic energy
• Petrology


  • Deals with the study of rocks
  • Most important for a civil engineer in the selection of suitable rocks for building stones, road metals, etc.
• Structural Geology


  A branch of geology that deals with the study of structures found in rocks. Also known as tectonic geology or tectonics.
• Structural Geology


  • It plays an important role in civil engineering in the selection of suitable sites for all types of projects such as dams, tunnels, multistoried buildings, etc.
• Mining Geology


  A branch of geology that deals with the application of geology to mining engineering in such a way that the selection of stable sites for quarrying and mines can be determined.
• Civil Engineering Geology


  A branch of geology that deals with all the geological problems that arise in the field of civil engineering along with suitable treatment. It includes the construction of dams, tunnels, mountain roads, building stones and road metals.
• The average distance from the Earth to the Sun is 92,956,050 miles (149,598,262 km)
• The length of a solar day (single rotation on Earth's axis) is 23.934 hours
• The Earth is about 4.54 billion years old
• Biosphere


  The part of Earth that supports life (biota-animals, plants and microorganisms) includes water, rock and soil of the earth's crust, and the atmosphere.
• Lithosphere


  The rocky material of the Earth's outer shell from the surface to about 100 km deep
• Layers of Lithosphere


  • Crust
  • Mantle
  • Core
• Hydrosphere


  The body of liquid on or near the surface of the Earth
• Atmosphere


  The gaseous blanket where important gases circulate
• Chemical Composition of the Atmosphere (Dry Air)

  • Nitrogen (78.084%)
  • Oxygen (20.546%)
  • Argon (0.934%)
  • Carbon Dioxide (0.0407%)
  • Others (Neon, Helium, etc.)
• Layers of Atmosphere

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere
• Troposphere


  The lowest major atmospheric layer, located from Earth's surface up to the bottom of the stratosphere. It extends upward to about 10km (6.2 miles or about 33,000 feet) above sea level. Humans live in this layer.
• Stratosphere


  The layer where the ozone layer is found. It absorbs high-energy ultraviolet from the sun. Commercial passenger jets fly in this layer.
• Continental Drift


  The large-scale horizontal movements of continents relative to one another and to the ocean basins during one or more episodes of geologic time. This concept was an important precursor to the development of the theory of plate tectonics.
• The 7 Continents

  • North America
  • South America
  • Antarctica
  • Europe
  • Asia
  • Africa
  • Australia
• Plate Tectonics


  The theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The plates act like a hard and rigid shell compared to Earth's mantle.
• The 9 Major Plates

  • North American Plate
  • Pacific Plate
  • Eurasian Plate
  • African Plate
  • Indo-Australian Plate
  • Indian Plate
  • South American Plate
  • Australian Plate
  • Antarctic Plate
• Earth's Processes

  • Internal Processes
  • Surface Processes
• Internal Processes


  Processes that originate deep in the Earth's interior, such as earthquakes and volcanism.
• Surface Processes


  Processes that affect the Earth's surface, mostly driven by water, wind, and gravity.
• Uniformitarianism


  The theory that Earth's features are mostly accounted for by gradual, small-scale processes that occurred over long periods of time.
• Catastrophism

  The theory that Earth's features are mostly accounted for by violent, large-scale events that occurred in a relatively short amount of time.
• Earthquake


  Sudden shaking or trembling of the ground caused by the sudden breakage or slippage of large rock masses below or at the surface of the earth
• Violent earthquakes release energy which is about 10,000 times of an atomic bomb
• Foreshocks


  • Tremors that occur before the main earthquake
• Aftershocks


  • Tremors that occur after the main earthquake, may happen for a few days or few weeks
• Types of earthquake


  • Tectonic earthquake - caused by movements in the earth's crust
  • Volcanic earthquake - movement of molten material or by gas pressure under a volcano
• Focus


  Location where the earthquake begins
• Epicenter


  Point on the earth's surface located directly above the focus of an earthquake
• Plate tectonics


  • Theory that the earth's crust and the upper mantle, which together form the lithosphere, is broken into large and smaller plates
  • These plates are moving around, and their movements cause changes in the earth's crust