1.Formation of Earth Agu24(1)

Welcome to

GEOL 107: Physical Geology

Dr. Lijun Liu

Department of Geology

Security Advice

Syllabus

• Can be downloaded from compass 2g

• Dr. Liu office: 61 Computing Applications Building (CAB)

• Email: ljliu@illinois.edu

• Office hour: Thu 1-4 pm

Syllabus Highlights

You must earn > 60% on the lab portion of the course to pass

TextbookEarth: Portrait of a Planet, 5th edition

By Stephen Marshak

Weekly online quiz:

Syllabus quiz due Friday Aug 28 by 10pm

Online Quiz, Chapter 3 due Mon. Aug 31 by 11am

Also on reserve at Granger Engineering LibraryE-book available for purchase

5th edition 4th edition

Labs

• Labs meet in Davenport 219

• Labs will meet this week (Aug 27 & 28)

• Lab manual available in book store

• You must earn > 60% on the lab portion to pass the course

I->Clicker registration

• Register your i->clicker in compass 2g.

• We use i->clicker in every lecture, so bring it every time.

• This is the majority of our in-class assignments

CPR Writing Assignments

• Calibrated Peer Review writing: – https://cpr.molsci.ucla.edu/cpr/cpr/login.asp

• A total of 4 assignments (drop two lowest)

• We will set up your accounts

• More instructions later– 1st assignment due in week 3

Field trip - mandatory

• Time: Oct. 10, Saturday

• Location: Turkey Run national park, Indiana

• More updates to come

Some policies to keep in mind…

• Absence of class– Proof of absence required

• Late assignment policy– I usually don’t allow late assignments, unless you have a

legitimate reason, such as sickness

• Complaints about class or assignment– Written (including emails) material required.

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What is Geology?

Geology from the Greek: geo “Earth”

The study of Earth

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What is Geology?

• Geology is the science that pursues an understanding of planet Earth.

• Geology uses scientific methods to explain natural aspects of the Earth – For example, how mountains form, or why oil

resources are concentrated in some rocks and not in others.

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Why is Geology important?

• Natural Hazards• Resources• Environmental Issues

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Why is Geology important?Natural Hazards

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Why is Geology important?Resources

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Why is Geology important?Environmental issues

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Physical Geology

• Physical Geology examines the materials composing Earth and seeks to understand the many processes that operate both beneath and upon its surface. Earth’s composition Temporal evolution of Earth’s interior and its

surface• It took time to reach today’s understanding.

Which of the following best illustrates that Earth is a dynamic planet?

A.Its regularly orbits the Sun

B.It has a thick atmosphere

C.It has similar topography to the Moon

D.It has earthquakes and volcanoes

I-clicker question:

Formation of Earth

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Modern view on the origin and evolution of the universe.

Big Bang theory

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Nebula theory

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The nebula theory

1) 14 billion years ago: the Big Bang: a huge explosion. Debris from this explosion began to cool and condense into the first stars and galaxies.

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The nebula theory

2) In our galaxy our solar system evolved.

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The nebula theory

3) 5 billion years ago, the bodies of the solar system condensed from an enormous cloud (the solar nebula)

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The nebula theory

4) Contraction of the nebula started to form the protosun; it also sped up the rotation and flattened to a disk

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The nebula theory

5) The proto-planets formed from materials condensed and accreted inside the cloud disk

Solar planets

Evolution of Earth

• At first, the proto-Earth was likely uniform in composition

Evolution of Earth

• As it grew, it began to heat up– Energy from collisions– Radioactive decay

Evolution of Earth

• The proto-Earth became so hot that it melted and denser materials sank to the interior in a process called differentiation

Present-day Earth① A thick atmosphere – similar to many other planets② Bi-modal topography – unique for Earth③ Earthquakes & volcanoes – unique for Earth④ Layered internal structure – similar to many other planets