Transcript General Geology

General Geology - GEOL 1113
Section 005
• Instructor: Dr. Glen S. Mattioli, Professor
• Office: Ozark Hall 27B
• Office Hours: MW 10:30-12:00 & TR 11:00-12:00
• Office Phone: 575-7295
• Class Web Page
– http://comp.uark.edu/~mattioli/geol_1113.html
• Email: [email protected]
2009 Exams, Syllabus, and Grading
Class Purpose: To introduce undergraduate
students to physical geology, Earth’s internal
structure and materials, and Geologic Time.
Emphasis will be on developing close connections
between Earth materials and processes within a
Plate Tectonic framework.
Three Partial Examinations and Comprehensive Final
Part I - Rocks and Minerals: Thurs. Sept. 24th
Part II - Geologic Time and Surface Processes: Thurs. Oct. 22nd
Part III - Deformation, Earthquakes, & Earth Structure: Tues. Nov. 24th
Part IV - The Big Picture: Tectonics & Orogenesis: Final Only
FINAL - Monday, December 14th, 10:00 AM – 12:00 PM
Some Expected Learning Outcomes
• An understanding of geologic time and dating methods.
• Development of skills to recognize major rock types, their
constituent minerals, and their origin.
• An appreciation of how the Scientific Method relates to the
development of the Theory of Plate Tectonics.
• An introduction to the origin and distribution of natural
resources.
• An understanding of three-dimensional analysis of Earth
structures (big and small), and the stresses that produce them
along with how major landforms relate to geological processes.
• An appreciation of origin of major geologic hazards and their
impacts.
Grades and Grading
Approximate Cutoffs for Letter Grades
>85% A
71-85%B
61-70%C
50-60%D
<50% F
Required Text
Physical Geology,
th
12
ed.
Charles C. Plummer
California State University at Sacramento
Diane H. Carlson
California State University at Sacramento
The Late David McGeary
Emeritus of California State University at Sacramento
NB that any edition of Plummer et al. from 10-12 will be OK
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Chapter 1
Introduction to
Physical Geology
Why Study Geology?
• Mitigating Geologic Hazards
– Earthquakes
– Volcanoes
• Supplying Things We Need
– Metals
– Minerals
– Petroleum
• Protecting the Environment
– Water cycle
– Global Change: Warming and Sea level rise
• Understanding Our Surroundings
– The Earth’s relationship to other planets
– Geological Time
Los Angeles Basin
Recent Southern California Earthquakes
Northridge (94)
San Fernando (71)
Whitter Narrorws (87)
Sierra Madre (91)
Long Beach (33)
From: http://www.scecdc.scec.org/labasin.html
Northridge Earthquake Facts
TIME: January 17, 1994
4:30:55 am PST
LOCATION: 34° 12.80' N, 118° 32.22'W;
20 miles west-northwest of Los Angeles
1 mile south-southwest of Northridge
MAGNITUDE: MW 6.7
TYPE OF FAULTING: blind thrust
FAULT INVOLVED: Northridge Thrust (also known as the Pico Thrust)
DEPTH: 18.4 km
Northridge CA earthquake
Jan. 17, 1994,
Northridge Earthquake
Northridge Aftershocks
Original AVS animation by Ian Sammis and Damien Sullivan.
Northridge Rupture Model
Wald, David J., Heaton, Thomas H., and Hudnut, K.W.
The Slip History of the 1994 Northridge, California, Earthquake Determined From Strong-Motion, Teleseismic,
GPS, and Leveling Data, Special Northridge Earthquake Issue of the Bull. of the Seismo. Soc. of America
Convergent Margin Magma Genesis
Eruption of Mt. Pinatubo, June 15, 1991
Soufriere Hills Volcano, Montserrat
Dome collapse pyroclastic flows
Photo credit: D. Williams
Plymouth, Montserrat - Destroyed by pyroclastic flows in 1996/7
Photo credit: G. Mattioli
Automobiles - Always Thirsty for Gas!
Source: http://www.wtrg.com/oil_graphs/oilprice1947.gif
Alaska Pipeline
Note: Oil Prices from WTRG Economics (www.wtrg.com) and Graduate numbers from University of Arkansas
200 4
200 2
200 0
199 8
199 6
199 4
199 2
199 0
198 8
198 6
198 4
198 2
198 0
197 8
197 6
197 4
197 2
1938 - 2005
70
$70
60
$60
50
$50
40
$40
30
$30
20
$20
10
$10
0
$0
World Oil Price Annual Average in 2004 US Dollars
80
197 0
196 8
196 6
196 4
196 2
196 0
195 8
195 6
195 4
195 2
195 0
194 8
194 6
194 4
194 2
194 0
193 8
Number of "First Degree" Geoscience Graduates per Year
University of Arkansas
Geoscience Graduates vs Oil Price
$80
Understanding our Environment
• Global change through time
• Stable Oxygen Isotope record – Earth’s climate has
varied considerably over geological time
• Sea Level Rise
• Related to retreat of the last continental glaciers\
The Ice Age – new warmer climate makes the Earth
more hospitable for humans
• Atmospheric temperature rise now also contributing
to additional rise in sea level – how will this impact
coastal cities?
Stable Oxygen Isotopes
d18O‰ = [(Rsample - Rstandard)/Rstandard] x 1000
Sea Level Changes
An Overview of Physical
Geology—Important Concepts
• Internal Processes: How the Earth’s
Internal Heat Engine Works
• The Earth’s Interior
• The Theory of Plate Tectonics
• Surface Processes: The Earth’s External
Heat Engine - the Sun
Some Heat Transfer Mechanisms
• Conduction - requires direct physical contact slow; generally associated with solids
• Convection - temperature gradient causes a
density gradient and results in flow - faster;
generally associated with fluids (liquids and gases)
• Advection - transfer of heat and mass - fluid flow
through cracks; can be fast
• Radiation - Direct heating via EM waves without
any requirement of mass along path - fastest
Convection Examples
Rayleigh-Benard Convection
Earth Structure
Convection in the Mantle
models
from: http://www.geo.lsa.umich.edu/~crlb/COURSES/270
convection in the mantle
observed heat flow
warm: near ridges
cold: over cratons
from: http://www-personal.umich.edu/~vdpluijm/gs205.html
From: "Dynamic models of Tectonic Plates and Convection" (1994) by S. Zhong and M. Gurnis
Earth’s Plates
crust
obvious from space that Earth has two fundamentally different
physiographic features: oceans (71%) and continents (29%)
from: http://www.personal.umich.edu/~vdpluijm/gs205.html
global topography
Convergent Margins and Magma Genesis
MORB Genesis
Submarine Pillow Basalt Formation
Ocean Crust Age-Depth Relations
Simplified Geologic Time Scale