Intro to Geol

• Geology


  study of earth and extraterrestrial bodies, its form and composition, and the processes
• Geology as a Discipline

  • Issues of Time
  • Issues of scale
  • Complexity of replicating natural phenomena
• Issues of time

  short vs long time
• Issue of scale

  • small vs large scale
  • e.g., maps
  • micro vs macro scale
  • micro - microscopic structures
  • macro - structures seen in the naked eye
  • local vs regional scale
  • local - landscape; what we see; e.g., singular mountain
  • regional - e.g., mountain range
• Branches of Geology

  Physical G.

  Historical G.
• Physical G.

  • rocks, minerals
  • processes that operate beneath or on the surface of the earth
  • most branches fall under this category
• Historical G.


  • origin and evolution of Earth throughout time
• Branches of Physical G.

  • Mineralogy
  • petrology (rocks)
  • volcanology
  • structured geology (structure and form of rock formation)
  • seismology
  • environmental geology
  • engineering geology
  • mining geology
  • petroleum geology
  • geomorphology (mountains, rivers, oceans)
  • planetary geology (extraterrestrial)
• Branches of Historical G.

  • Paleontology (fossils; picture of the past)
  • Stratigraphy (strata - layers of rock)
  • Geochronology
  • earth's time
  • use isotopes to measure earth's time
  • International chronostratigraphic chart)
• Early Schools of Though in G.

  • Catastrophism
  • Uniformitarianism
• Catastrophism 


  • sudden, worldwide catastrophes are the agents of change that alter the physical features of the Earth over time
  • widely accepted by theologians in the early 1800s due to similarity with Biblical evidence as Noah's Flood
  • propagated by the church
  • Baron Georges Cuvier, 16th Century
• Uniformitarianism was proposed by James Hutton, known as the Father of Modern Geology
• Uniformitarianism advocates the idea that the Earth is continuously modified by geologic processes that have always operated throughout time, at different rates
• The key concept of Uniformitarianism is "the present is the key to the past"
• According to Uniformitarianism, studying the physical, chemical, and biological laws that operate today can help us understand how the Earth has evolved through time
• Uniformitarianism was popularized by Charles Lyell's Principle of Geology
• Charles Lyell proposed actualism, which is based on the principles of Uniformitarianism
• Accepting Uniformitarianism means accepting that the Earth has been evolving for a long time
• Things that took a long time to develop according to Uniformitarianism include Continental drift, the formation of India, and the development of Baguio