POG midterms

• Geology


  Looking at the natural hazards, climate changes, mineral resources, impact of environmental developments, changes in the earth's geography, etc.
• Siccar Point


  • Tectonically disturbed
  • Horizontal - Vertical
  • Vertical beds overlaid by horizontal beds
• Geology


  Base level study of earth, internal and external process

  
• Earth Science


  Different process of geology
• Geosciences


  Earth science that is partnered with other disciplines of science
• Nebular Hypothesis

  1. The solar system evolved from an enormous rotating cloud called the solar nebula

  2. The nebula was composed mostly of hydrogen and helium

  3. 5 billion years ago, the nebula began to contract

  4. It assumed a flat, disk shape with the protosun (pre-Sun) at the center

  5. Inner planets begin to form metallic and rocky clumps

  6. Larger outer planets began forming from fragments with a high percentage of ice
• Layers form on Earth

  1. As earth formed, the decay of radioactive elements and heat from high-velocity impacts caused the temperature to increase

  2. Lighter rocky components floated outward, toward the surface

  3. Gaseous material escaped from Earth's interior to produce the primitive atmosphere
• Hydrosphere


  Ocean is the most prominent feature, holding about 97% of Earth's water, also includes fresh water found in streams, lakes, and glaciers, as well as that found groundwater
• Aristotle: 'The position of land and sea had changed over a long period of time as fossils from rocks were similar to those found on the beach, indicating the fossils were once living animals'
• Copernicus: 'The earth revolves around the sun'
• James Ussher: 'Catastrophe believer, landscapes are formed due to catastrophe'
• James Hutton: 'Theory of the earth, "Physical, chemical, and biological laws that operated today have also operated in the geologic past"'
• Atmosphere


  Thin, tenuous blanket of air, one half lies below 5.6 kilometers (3.5 miles)
• Biosphere


  Includes all life, concentrated near the surface in a zone that extends from the ocean floor upward for several kilometers into the atmosphere
• Geosphere


  Rocks and minerals on Earth
• Plate tectonics


  The Earth's outer shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and Earth's crust itself
• Latitude


  Distance north or south of the equator, measured in degrees
• Longitude


  Distance east or west of the prime meridians, measured in degrees
• Topographic maps

  Represent Earth's surface in three dimensions, showing elevation, distance directions, and slope angles, using contour lines

  
• System


  Any size group of interacting parts that form a complex whole
• Closed systems


  Self contained (e.g., an automobile cooling system)
• Open systems


  Allow both energy and matter to flow in and out of the system (e.g., a river system)
• Earth system science


  Studies Earth as a system that is composed of numerous parts, or subsystems
• Matter


  Anything that occupies space and has mass
• Elements


  The basic building blocks of minerals, over 100 elements are known
• Atoms


  The smallest particles of matter, containing protons, neutrons, and electrons
• Modern atomic theory


  • An atom is the smallest fraction of an element that can exist and still show the characteristics of that element
  • The main building blocks of an atom are protons, neutrons, and electrons
  • A typical atom consists of a nucleus of protons and neutrons and a cloud of electrons surrounding the nucleus
  • The distinguishing feature of an atom of a given element is the number of protons in the nucleus
  • Normally atoms are electrically neutral because they have one negatively charged electron for each positively charged proton
  • Electrically charged atoms, called ions, are produced by the gain or loss of electrons
  • Isotopes, which are varieties of a given atom (element), are produced by variations in the number of neutrons in the nucleus
  • Atoms combine, mostly through ionic or covalent bonding, to form minerals
• States of matter

  • Solid - Has definite shape and volume
  • Liquid - Has definite volume but has no fixed shape
  • Gas - Has no fixed shape or volume
• Energy levels or Shells


  Surround the nucleus and contain electrons
• Atomic Number


  Number of protons in the nucleus of an atom
• Isotopes


  Have the same number of protons but varying numbers of neutrons, have different mass numbers, and can be radioactive
• Mass number


  Number of neutrons and protons in the nucleus of an atom
• Atomic Bond


  Forms when an atom's outermost energy level does not contain a maximum number of electrons, resulting in ionic, covalent, or metallic bonds
• Compound


  Two or more elements that are chemically combined in specific proportions
• Ion


  An atom that gains and loses electrons
• Atomic Bonds

  • Ionic bonds - form between positive and negative ions
  • Covalent bonds - form when atoms share electrons
  • Metallic bonds - form when metal ions share electrons
• Minerals


  Naturally occurring, solid substances with an orderly crystalline structure and definite chemical composition, generally considered inorganic
• Mineral formation

  • Crystallization from magma/lava
  • Precipitation - mineral forms by crystallization from a solution
  • Pressure and temperature - solid minerals react with each other under high pressures and temperatures, and new minerals are formed
  • Hydrothermal solutions - from hot waters circulating in Earth's crust through fractures, they eventually create metallic-rich fluids concentrated in a selected volume of rock, which become supersaturated and then precipitate ore minerals

  
• Classification of minerals based on composition

  • Silicates - silicon and oxygen combine to form a structure called the silicon-oxygen tetrahedron
  • Carbonates - minerals that contain the elements carbon, oxygen, and one or more other metallic elements
  • Oxides - minerals that contain oxygen and one or more other elements, which are usually metals
  • Sulfates and Sulfides - minerals that contain the element sulfur
  • Halides - minerals that contain a halogen ion plus one or more other elements
  • Native Elements - minerals that exist in relatively pure form
• Properties of minerals

  • Color - small amounts of different elements can give the same minerals different colors
  • Streak - the color of a mineral in its powdered form
  • Luster - used to describe how light is reflected from the surface of a mineral
  • Crystal form - the visible expression of a mineral's internal arrangement of atoms
  • Hardness - a measure of the resistance of a mineral to being scratched, using the Mohs Scale
  • Cleavage - the tendency of a mineral to cleave, or break, along flat, even surfaces
  • Fracture - the uneven breakage of a mineral
  • Density - the ratio of an object's mass to its volume