How is Geology studied?
- Scientific methods
- The Scientific Method
How is Geology studied?
- Observation platforms and sample collection (field)
- Aerial Photographs
- Ships
- JOIDES Resolution
- Ocean Drilling Program
- Submersibles
- Field Work (Feet)
- Drill Rigs, Geophysical Methods
- Extraterrestrial Vehicles
- Sample Analysis (laboratory)
- Physical (e.g., grain size), microscopy, chemical
- Microscopy
- Scanning Electron Microscopy (SEM)
- Laboratory Analyses
- Chemical analysis
- Isotopic analysis
- Particle size
- Mechanical property analysis
- Computer modeling (office)
- Physics, chemistry, biology
- Ex: General circulation model (climate)
Subdivisions in Geology
- Physical Geology
- Earth Materials
- Earth Processes
- Historical Geology
- Paleontology
History of the Science of Geology
History of Geology:
Early Misconceptions
- Origin of fossils
- Aristotle (Greece, 4th century B.C.)—with regard to fossil fish: "a
great many fishes live in the Earth motionless and are found when excavations
are made"
- Mercati (Italy, 1574)—"fossils shells are mere stones which had assumed
their peculiar configuration from the influence of heavenly bodies"
- Age of Earth
- Dilemma: reconciling geologic features with religious teachings
- Archbishop Ussher (mid 1600’s: Earth created 4004 BC and is about 6000
yr old)
- _____________________________—geologic features formed by relatively
short-lived catastrophic events
Modern Geology
- ________________________—"father of modern geology"
- 18th Century Scottish physician
- Carefully observed geologic features and natural processes
- Developed a principle called Uniformitarianism
Expansion of Hutton’s "Theories"
- John Playfair: "Illustrations of the Huttonian Theory" (1802)
- _______________________l: "Principles of Geology" (1830-1872) (Subtitle:
"Being an Attempt to Explain the Former Changes of the Earth’s Surface, by
Reference to Causes now in Operation")
Modern Geology (cont.)
- ____________________________
- The physical, chemical, and biological laws that operate today operated
in the geologic past
- Processes active today are responsible for geologic features
- To paraphrase: "the present ____________________________"
Catastrophism versus Uniformitarianism
- Mountain-building
- Deposition of thick sediment accumulations
- Erosion of Badlands
- Erosion of Channeled Scablands
- Snowball Earth?
- Asteroid impact