Historical Geology (Kowalewski)
WEEK 1 (Spring 2001)
1
WEEK 1 - Historical Geology
Lecture 1. Historical Geology, Concept of Time in Geology
Course Web Page http://www.cyber.vt.edu/geol1014/index.htm
Historical Geology
What is it?
Why should you care?
Catalog Description
1014: HISTORICAL GEOLOGY. History of the earth as inferred from studies of rocks, fossils,
and the earth's interior. Topics include: age of earth, rocks, and fossils; origin and history of
continents and ocean basins; mountain building; ice ages; motion of continents through time;
evolution of life.
Course objectives
To learn:
Methods used by geologists to study the history of the earth
The historical sequence of geologic events
How life has changed during geologic history
Why should you care?
Understanding geologic history is a necessary background for understanding the distribution of
natural resources, environmental conditions and scenic variety on our home planet.
Only with that knowledge can one make wise political and social judgments that will determine
future conditions for our descendants.
Relevance of This Course
Understanding why the earth and life are as they are
Background for serious political and social decisions in the future
Example: What permitted the U. S. A. to become the most powerful nation in the world?
North America was in the tropics 300 million years ago and rivers drained rising mountains.
(Coal)
Cyanobacteria lived in shallow seas 2.2 to 1.8 billion years ago when there was little or no free
oxygen
(Iron Ore)
The Gulf of Mexico was opening; Upwelling took place on the developing Gulf Coast
150 to 100 million years ago
(Oil)
Igneous intrusions occurred in Arizona and Utah
60 to 40 million years ago
(Copper)
Geologic Time
The time scale — something you must learn
How geologists diagram time sequences
Perspective on large numbers
Historical Geology (Kowalewski)
WEEK 1 (Spring 2001)
2
Units of Time
Time Units Used in Everyday Life
Seconds
Minutes
Hours
Days
Weeks
Months
Years
Centuries
Millennia
Time Units in History of