Lecture 1

• Geology


  The study of the Earth, its origin and history, the processes that shape it, and the resources that could be obtained from it
• Branches of Geology

  • Historical Geology
  • Physical Geology
  • Environmental Geology
  • Engineering Geology
  • Mining Geology, Petroleum Geology
  • Minerology, Petrology
  • Geomorphology
  • Geophysics, Geochemistry
• Historical Geology


  • The study of the Earth's history and evolution, involving understanding geological processes in the context of time, from the formation of the Earth to the development of its landscapes and life form.
  • Researchers in this field use rocks and fossils to reconstruct the sequence of events that have shaped the Earth and its life over billions of years
  • This includes studying major events like mass extinctions, continental drift, and climate changes
• Branches of Historical Geology

  • Paleontology
  • Stratigraphy
  • Geochronology
• Paleontology


  The study of ancient life through the examination of fossils
• Stratigraphy 


  • The study of rock layers (strata) and layering (stratification)
  • It is fundamental to understanding how the Earth's surface has been shaped over time.
• Geochronology


  • The science of determining the age of rocks, fossils, and sediments
  • This discipline uses a variety of dating methods, including radiometric dating (measuring radioactive decay), to establish the timing of geological events and the age of the Earth.
• Physical Geology


  • Focuses on the processes currently shaping the Earth's surface and interior, and the materials composing it
  • This field examines phenomena such as earthquakes, volcanoes, erosion, and sedimentation. It also studies rocks and minerals, their formation, and how they change over time.
• Branches of Physical Geology

  • Volcanology
  • Seismology
• Volcanology


  The study of volcanoes and volcanic eruptions; their processes, dynamics, and characteristics
• Seismology


  The study of earthquakes and the movement of seismic waves through the earth, including sources and effects of earthquakes
• Environmental Geology


  • Applies geological science to address issues affecting the environment and human society, including studying natural hazards, managing natural resources, and understanding human impacts on the Earth
  • It involves studying natural hazards (like landslides and earthquakes), managing natural resources, and understanding human impacts on the Earth.
  • This field seeks to mitigate environmental problems through geological knowledge.
• Engineering Geology


  • Applies geological data, techniques, and principles to the study of rock and soil surfaces for the purpose of engineering design and construction
  • It is crucial in ensuring the stability and safety of structures like buildings, dams, and tunnels, assessing geological hazards, and determining the best materials for construction projects.
• Mining Geology


  • Involves the study of the Earth's resources (such as minerals, metals, and fossil fuels) from discovery through to exploitation, including exploration techniques, resource estimation, and sustainable extraction
• Petroleum Geology


  • Focuses on the exploration and extraction of oil and natural gas
  • This field integrates sedimentology, structural geology, and stratigraphy to understand the subsurface conditions favorable for oil and gas deposits. It's critical for energy resources management.
• Mineralogy


  • The study of minerals, their composition, structure, properties, and the processes that lead to their formation
  • It involves identifying and classifying minerals, understanding their geological significance, and exploring their practical applications (e.g., in materials science, technology, and industry)
• Petrology


  • The branch of geology that studies rocks and the conditions under which they form
  • It covers igneous, metamorphic, and sedimentary rocks, analyzing their origins, mineral compositions, and the geological processes that transform them
• Geomorphology


  • The study of landforms and the processes that shape the Earth's surface
  • It investigates the formation and evolution of mountains, valleys, coastlines, and other landscape features, focusing on the interaction between geological structures and surface processes
• Geophysics


  • Applies the principles of physics to study the Earth's interior and its physical properties, using techniques like seismic wave analysis, magnetic and gravitational field studies
  • Techniques like seismic wave analysis, magnetic and gravitational field studies are used to explore the Earth’s subsurface structures.
  • It’s crucial for understanding the Earth's internal composition and dynamics
• Geochemistry


  • Involves the study of the chemical composition of the Earth and its rocks and minerals, as well as the chemical processes and reactions that govern the composition of rocks and soils
  • It integrates chemistry and geology to unravel the Earth's chemical composition, the cycles of chemical elements, and the interaction of Earth's spheres (biosphere, lithosphere, atmosphere, and hydrosphere)
• Engineering Geology


  • Deals with the application of geology for a safe, stable, and economic design and construction of civil engineering projects
  • Application of geological knowledge in planning, designing and construction of civil engineering projects
• Geology in Construction Jobs

  • Planning
  • Design
  • Construction
• Topographic Maps


  Give details that are essential to understand relative merits and demerits of all the possible sites for the proposed structure, including the presence and nature of slopes, size, contours and depths of valleys and gorges, and rate of change of elevation
• Hydrological Maps


  Give details about the distribution and geometry of the surface water channels and the occurrence and depth contours of ground water below the surface
• Geological Maps


  Depict the petrological characters and structural disposition of rock types as developed in the proposed area, providing useful information regarding the fracturing and displacement that the site rocks might have undergone in the past
• Design in Engineering Geology


  • This is the application of geological characters and conditions that finally dictate the broad contours of the engineering design of an engineering project, be it a high rise building, road, bridge, dam or a tunnel, etc
• Construction in Engineering Geology


  • Geological knowledge is applied to the selection and proper use of the right type of materials of construction derived from the natural bedrocks, soils, banks and beaches
• Geology in Water Resources Development


  • Exploration and development of water resources within areas, requiring an understanding of the water cycle in all essential details
• Geology in Town and Regional Planning


  • Applying geological knowledge to land utilization in the most beneficial and aesthetic manner for developing cities and towns, with the aim of deriving maximum benefits from the natural environment with minimum disturbance
• The Earth is commonly described as a spheroid in shape
• Composition of the Earth's Atmosphere (Dry Air)

  • Nitrogen (78.084%)
  • Oxygen (20.946%)
  • Argon (0.934%)
  • Carbon Dioxide (0.033%)
  • Others (0.003%)
• Layers of the Atmosphere

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
• Troposphere


  • The lowermost zone of the atmosphere rising from the surface of the earth and extending, on an average to a height of 11km
  • Its upper boundary called tropopause lies at about 9km above the poles and at 18km above the equator.
• Stratosphere


  • The second layer of the atmosphere starting from the tropopause and extending up to an average height of 50km, where the temperature becomes constant for a height of 20km and then starts increasing
  • It is where the ozone layer is
• Ozone Layer


  Starts at a height of 9km above the surface and continues up to 35km, with the maximum concentration of ozone at a height of 20-25km
• Mesosphere


  The third thermal zone of the atmosphere which begins at stratopause at about 50km above the surface and continues up to a height of about 80km
• Thermosphere


  The fourth and last zone of the atmosphere, starting at about 80km and extending up to 500km and beyond
• Ionosphere


  • A specialized zone that starts from 80km and extends upwards to variable heights,
  • most strongly ionized layer located at the base and designated as the D-Layer
• Exosphere


  The region of the atmosphere beyond 700km, a low-density and high temperature region with a minimum atomic collusions
• Lithosphere


  • It is the stony part of the Earth (litho = stone) and it includes all the solid materials composing the Earth from the surface downwards.
  • It include only the uppermost shell of the earth, crust and a part of the second layer, the mantle, up to which the material exists in a definite solid state.