Frank Mitchell

Geology 101 notes

What follows are my lecture notes from Mickey Gunther’s Geology 101 course. As these are personal notes, please don’t expect them to be complete in any way, shape, or form. They’re here as an illustrative example of several salient points that will eventually be elaborated on when I find the time.

Actually, they’re here because I want them to be. Just like I’ve always wanted to use the word ‘salient’ in a sentence.

25 August 2004


27 August 2004

“If you can’t grow it, you have to mine it.”

Part 1: Overview

  1. Define geology and it’s subdisciplines
  2. The Earth: The BIG Picture


The study of the planet Earth - the materials of which it is made, the processes that act on those materials, the products that are formed, and the history of the planet and its life forms since its origin.

Physical geology vs. historical geology

Geology can tie into other disciplines.

[diagram showing how the geological disciplines relate]

[diagram showing the rock cycle]

The Earth: The BIG Picture

People started measuring earthquakes in the ‘40s and '50s and figured out the shape and motion of plates on the Earth.

30 August 2004

Part 2: Minerals

  1. Motivation: Why bother?
  2. Chemistry review
  3. Physical properties of minerals and crystal structures
  4. Mineral classification and formation

A. Motivation

What do the following have in common?

Good mineral, bad mineral?

Mineral: A naturally occuring homogenous solid with a definite, but not fixed, chemical composition, and a highly ordered atomic arrangment, generally formed by inorganic processes.

  1. naturally occuring
  2. chemical composition
  3. atomic arangment
  4. inorganic

Au - gold

NaCl - halite (table salt) p.86

The arangment of atoms defines the shape of the mineral.

muscavite - KAl2(AlSi3O10)(OH)2

Shine x-rays on minerals to see their atomic shape. Inverse finite transform produces the atomic shape (of the x-ray picture).

1 November 2004

Caves and ground water

  1. Caves = fun
  2. Ground water = $$ and importance

Cave development

  1. Cave formation: How do caves form?

    • Mechanical and chemical weathering of carbonates -> limestone, calcite
    • Cracks fill with water and a chemical reaction takes place
    • H2O + CO2 + CaCO3 -> Ca3+ + 2HCO3-
    • The right part of the equation above is acidic
  2. Cave formations: How do they form?

    • Percipitation of minerals in the cave (deposition)
    • Stalactites - hang from the ceiling
    • Stalagmites - grow from the floor
    • Columns - when a stalactite and a stalagmite meet
    • Gypsum flowers, hair, needles - form in dryer caves
    • Formations occur due to CO2 changes
    • Temperature in a cave is the average yearly temperature in that area
    • Caves are almost 100% humid