Big Goals for Geologic Time/Stratigraphy
Initial Publication Date: June 19, 2006
Scale/Magnitude/Hierarchy of Geologic Time
- Earth is 4.5 billion years old- what does this mean
- Resolution of geologic time—how accurately do we know time in different parts of the past; Our view of time is telescoped with a finer units closer to the present
- How do we know/measure geologic time-methods
- Absolute/Radiometric Dating
- Relative Dating/stratigraphic principles
- Cyclostratigraphy
- Biostratigraphy
- Magnetostratigraphy
- Chemostratigraphy
- Thresholds/benchmarks in geologic history; big natural changes/ what makes the major divisions in the geologic time scale
Earth has a history and is always changing- How do we know?
- Reading the rock record
- Proxies
- Nature of rock record- composite nature of rock record (space for time)
How do geoscientists test theories and draw conclusions: what constitutes robustness?
- Geoscientific method brings together multiple lines of evidence.
- Critical evaluation of data.
Rates and processes in the Earth system
- Gradual change vs abrupt events
- External vs internal forcing
- How do measure/know?
- Cyclicity/cycles
- Transgression/regression
Evolution of life
- Relationship to human activity
- What is evolution? What is evidence? Perception
- Missing links/incomplete nature of rock record
- Biotic response to global change
