Historical Geology - Earth as a system Flashcards
Describe the Scientific Method?
- works by testing hypotheses
- hypothesis can be accepted or rejected; they are never proven
- hypotheses - theory - law
How do we test Hypotheses?
- By experiment
- By numerical simulation
- By examining results of natural processesto deduce nature’s experimental conditions
Describe the meteoric impact at the K-T boundary.
High IRIDIUM content
- shocked quartz
- glass spherules
- impact crater on Yucatan Penensula
What are Steno’s three principles for sedimentary rocks? Describe each.
- Principle of Superposition - younger over older
- Principle of Original Horizontality - Layers initially deposited horizontally and any deformation much have occurred after deposition.
- Principle of Lateral Continuity - Strata are originally unbroken flat expanses, but a river or other change in the landscape can break this lateral continuity.
Who used the term Catastrophism?
Georges Cuvier
What is Catastrophism?
Earths history explained by a series of supernaturally derived catastrophes. (specifically floods)
What was James Hutton’s theory?
Uniformitarianism - Present geological processes have been operating throughout Earth’s history, and can be used to explain past geologic processes. the present is the key to the past. eg. ripple marks on sandstone formed the same way ripple marks form in the sand today. Did not believe in catastrophism. Uniformitarianism = Actualism - the present is A key to the past.
What else does uniformitarianism apply to?
biological processes
What is a stromatolite?
mound-shaped, finely layered rock formed by growing communities of bacteria.
What modern paradigms and systems do we need to keep in mind moving forward?
- Plate tectonics
- the water cycle
- evolution
- geologic time
Describe the water cycle.
- condensation
- evaporation (from plants, oceans, lakes, streams)
- precipitation
- surface runoff
