Geology 142Deciphering Earth History

Dr. Bruce F. Ruegerbfrueger@colby.edu

Phone: 859.5806Office: Mudd 214 Lab: Mudd 219

Text: The Earth Through Time (8th edition) Author: Harold L. Levin

Lab Manual: Deciphering Earth History (4th ed.)Author: Gastaldo, Savrda, and Lewis

Office Hours:Monday, Wednesday: 9:30 - 10:30Tuesday, Thursday: 9:30 - 11:00

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.

Course Format(What You Need to Know To Do Well)

Lecture Part of the CourseConsists of:

Three meetings each week.Three written experiences (exams).Exams will be worth 600 pointsWritten 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 labLab starts this week.

Field Trip to Acadia National ParkDate to be determined

Things You Might Find Useful to Bring:

1. Some colored pencils or pensThese will be useful for diagrams.

2. 5x7 index cardsThese will be used for questions orimpromptu 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 Englishmeasurements to Metric using the following:

1 inch = 2.54 centimeters3.3 feet = 1 meter0.62 miles = 1 kilometer1.1 quarts = 1 liter1 pound = 0.45 kilogramsC (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 3-4,000,000 yBPDemise of the Dinosaurs 65,000,000 yBPFirst Land Plants 483,000,000 yBPFirst Fish 505,000,000 yBPFirst Shelled Invertebrates 570,000,000 yBPFirst Appearance of Life 3,770,000,000 yBPOldest Known Earth Rocks 3,960,000,000 yBPAge of the Earth 4,600,000,000 yBP

Appearance of first Hominids 4 mmDemise of the Dinosaurs 65 mmFirst Land Plants 483 mmFirst Fish 505 mmFirst Shelled Invertebrates 570 mmFirst Appearance of Life 3,770 mmOldest Known Earth Rocks 3,960 mmAge of the Earth 4,600 mm

GEOLOGIC TIME in PERSPECTIVE

Founders of Historical Geology

Can be traced back to classical Greece

Nicolaus Steno (Neils Stensen) 1638-1687

Originally a Danish physicianAn expert in anatomy

(Public Dissections)Developed the fundamental

principles of historicalgeology

Physician to the de Medicifamily in Florence

Nicolaus Steno (Neils Stensen) 1638-1687

In 1669, Steno wrote De solido intra solidum naturaliter

contento dissertationis prodromusProdromus to a dissertation on Solids

Naturally Enclosed in Solidsonly 78 pages long

Founders of Historical Geology

Founders of Historical GeologySuperposition - 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 needto consider othersedimentarystructures, like ripple marks,mudcracks,graded bedding, geopetal structuresor cross-bedding to help determineup direction.

Can also use vesicles inlava flows.

Founders of Historical GeologyPrinciple 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 GeologyPrinciple of Lateral Continuity - The scientific law stating thatas originally deposited, strata extend in all directions until theyterminate by thinning at the margins of the basin, endabruptly against some former barrier to deposition, or gradelaterally into a different kind of sediment.

Founders of Historical GeologyJohn Strachey 1671-1743

Used superposition and original lateral continuityDetermined the stratigraphic succession of coals in EnglandRecognized what would later be termed unconformities

Performed local-scale observations.

Founders of Historical GeologyGiovanni Arduino 1714-1795

Had a broader global view of sedimentary layersDeveloped the first classification of rocks and relative ages

Primary Mountains crystalline rocksoldest rocks on Earthlater became igneous/metamorph.

Secondary Mountains layeredfossiliferous rockslater sedimentary rocks

Tertiary unconsolidated sedimentslava flows

Founders of Historical GeologyJohann Lehmann 1719-1767Georg Füchsel 1722-1776

Came up with classification similar to that of ArduinoDeveloped 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 GeologyPeter Simon Pallas 1741-1811

Improved geologic history of the mountains of EuropeDeveloped the general geologic history of the UralsObserved changes in rock assemblages going from margins to

the core of mountains.

Reise durch verschiedene Provinzen des Russischen Reiches 1771-1776Journey Through Several Provinces of the Russian Empire