Transcript Slide 1

Geology 142
Deciphering Earth History
Dr. Bruce F. Rueger
[email protected]
Phone: 859.5806
Office: Mudd 214
Lab: Mudd 219
Office Hours:
Monday, Wednesday: 9:30 - 10:30
Tuesday, Thursday: 9:30 - 11:00
Text: The Earth Through Time (8th edition)
Author: Harold L. Levin
Lab Manual: Deciphering Earth History (4th ed.)
Author: Gastaldo, Savrda, and Lewis
Course Format
(What You Need to Know To Do Well)
1. Come to class (all the time).
2. Buy the textbook and the lab manual.
3. READ the textbook and the lab manual.
(Preferably before you come to class)
4. Do the assignments in lecture and lab.
5. Go to lab.
(the lab guy is really tough about this)
6. Study for the exams.
Lecture Part of the Course
Consists of:
Three meetings each week.
Three written experiences (exams).
Exams will be worth 600 points
Written exercises and projects are
worth 150 points.
There will be some unannounced exercises.
Lecture portion of the course is worth 750 points.
Lecture is worth 75% of your course grade.
I strongly recommend that you buy the book.
The Geology 142 Web Site
http://www.colby.edu/personal/b/bfrueger/
Laboratory Part of the Course
Consists of:
One laboratory session each week.
Lab exercises are worth 150 points.
Lab final is worth 100 points.
Lab portion of the course is worth 250 points.
Lab is worth 25% of your course grade.
You DO need the laboratory manual.
It would be beneficial to read the lab before lab
Lab starts this week.
Field Trip to Acadia National Park
Date to be determined
Things You Might Find Useful to Bring:
1. Some colored pencils or pens
These will be useful for diagrams.
2. 5x7 index cards
These will be used for questions or
impromptu written exercises.
3. An interest in learning about the Earth.
IMPORTANT STUFF YOU SHOULD KNOW
(at least to start with today)
You should be able to do simple conversion from English
measurements to Metric using the following:
1 inch = 2.54 centimeters
3.3 feet = 1 meter
0.62 miles = 1 kilometer
1.1 quarts = 1 liter
1 pound = 0.45 kilograms
C (Celsius) = (5/9)(F-32)
F (Fahrenheit) = C (9/5)+32
GEOLOGY
Study of planet Earth
Includes:
materials (131/141)
physical & chemical processes (131/141)
history of Earth and life on it (142)
Based on physics, chemistry, biology,
astronomy and mathematics
TIME
Age of the Earth?
Time is a critical ingredient to most geologic processes.
Geologic time has an immense vastness.
We have 4.6 BILLION years to work with.
(info comes from the moon and meteorites)
To us a decade is a long time!
Lots of events happen in this interval of time.
How big is a billion?
Consider 1,000,000,000 seconds.
1,000,000,000 seconds equals 31.71 YEARS!
GEOLOGIC TIME in PERSPECTIVE
Appearance of first Hominids
Demise of the Dinosaurs
First Land Plants
First Fish
First Shelled Invertebrates
First Appearance of Life
Oldest Known Earth Rocks
Age of the Earth
3-4,000,000 yBP
65,000,000 yBP
483,000,000 yBP
505,000,000 yBP
570,000,000 yBP
3,770,000,000 yBP
3,960,000,000 yBP
4,600,000,000 yBP
GEOLOGIC TIME in PERSPECTIVE
Appearance of first Hominids
Demise of the Dinosaurs
First Land Plants
First Fish
First Shelled Invertebrates
First Appearance of Life
Oldest Known Earth Rocks
Age of the Earth
4 mm
65 mm
483 mm
505 mm
570 mm
3,770 mm
3,960 mm
4,600 mm
Founders of Historical Geology
Can be traced back to classical Greece
Nicolaus Steno (Neils Stensen)
1638-1687
Originally a Danish physician
An expert in anatomy
(Public Dissections)
Developed the fundamental
principles of historical
geology
Physician to the de Medici
family in Florence
Founders of Historical Geology
Nicolaus Steno (Neils Stensen)
In 1669, Steno wrote
De solido intra solidum naturaliter
contento dissertationis prodromus
Prodromus to a dissertation on Solids
Naturally Enclosed in Solids
only 78 pages long
1638-1687
Founders of Historical Geology
Superposition - The scientific law stating that in any
unaltered sequence of rock strata, each stratum is younger
than the one beneath it and older than the one above it, so
that the youngest stratum will be at the top of the sequence
and the oldest at the bottom.
Founders of Historical Geology
Superposition, con’t.
With tilted beds, we need
to consider other
sedimentary
structures, like
ripple marks,
mudcracks,
graded bedding,
geopetal structures
or cross-bedding
to help determine
up direction.
Can also use vesicles in
lava flows.
Founders of Historical Geology
Principle of Original Horizontality - The scientific law stating
that sediments settling out of a fluid (air and water) are
deposited horizontally or nearly horizontally in layers that lie
parallel or nearly parallel to the Earth’s surface.
Founders of Historical Geology
Principle of Lateral Continuity - The scientific law stating that
as originally deposited, strata extend in all directions until they
terminate by thinning at the margins of the basin, end
abruptly against some former barrier to deposition, or grade
laterally into a different kind of sediment.
Founders of Historical Geology
John Strachey
1671-1743
Used superposition and original lateral continuity
Determined the stratigraphic succession of coals in England
Recognized what would later be termed unconformities
Performed local-scale observations.
Founders of Historical Geology
Giovanni Arduino
1714-1795
Had a broader global view of sedimentary layers
Developed the first classification of rocks and relative ages
Primary Mountains crystalline rocks
oldest rocks on Earth
later became igneous/metamorph.
Secondary Mountains
Tertiary
layered
fossiliferous rocks
later sedimentary
rocks
unconsolidated sediments
lava flows
Founders of Historical Geology
Johann Lehmann 1719-1767
Georg Füchsel
1722-1776
Came up with classification similar to that of Arduino
Developed stratigraphic successions of rocks in Thuringia,
and the Hartz and Ertz Mountains.
Began to understand the events that lead
to mountain building
Lehmann
Founders of Historical Geology
Peter Simon Pallas
1741-1811
Improved geologic history of the mountains of Europe
Developed the general geologic history of the Urals
Observed changes in rock assemblages going from margins to
the core of mountains.
Reise durch
verschiedene Provinzen
des Russischen Reiches
1771-1776
Journey Through
Several Provinces
of the Russian Empire