General Geology - GEOL 1113 Section 005

Transcription

1 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: Class Web Page mattioli@uark.edu

2 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. 24 th Part II - Geologic Time and Surface Processes: Thurs. Oct. 22 nd Part III - Deformation, Earthquakes, & Earth Structure: Tues. Nov. 24 th Part IV - The Big Picture: Tectonics & Orogenesis: Final Only FINAL - Monday, December 14 th, 10:00 AM 12:00 PM

3 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.

4 Grades and Grading Approximate Cutoffs for Letter Grades >85% A 71-85% B 61-70% C 50-60% D <50% F

5 Required Text Physical Geology, 12 th 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 will be OK Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

6 Chapter 1 Introduction to Physical Geology

7 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

8 Los Angeles Basin

9 Recent Southern California Earthquakes Northridge (94) San Fernando (71) Sierra Madre (91) Whitter Narrorws (87) Long Beach (33) From:

10 Northridge Earthquake Facts TIME: January 17, :30:55 am PST LOCATION: ' N, '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

11 Northridge CA earthquake Jan. 17, 1994,

12 Northridge Earthquake

13 Northridge Aftershocks

14 Original AVS animation by Ian Sammis and Damien Sullivan.

15 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

16 Convergent Margin Magma Genesis

17 Eruption of Mt. Pinatubo, June 15, 1991

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19 Soufriere Hills Volcano, Montserrat Dome collapse pyroclastic flows Photo credit: D. Williams

20 Plymouth, Montserrat - Destroyed by pyroclastic flows in 1996/7 Photo credit: G. Mattioli

21 Automobiles - Always Thirsty for Gas!

22 Source:

23 Alaska Pipeline

24 80 University of Arkansas Geoscience Graduates vs Oil Price $ Number of "First Degree" Geoscience Graduates per Year $70 $60 $50 $40 $30 $20 $10 World Oil Price Annual Average in 2004 US Dollars $0 Note: Oil Prices from WTRG Economics ( and Graduate numbers from University of Arkansas

25 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?

26 Stable Oxygen Isotopes 18 O = [(R sample - R standard )/R standard ] x 1000

27 Sea Level Changes

28 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

29 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

30 Convection Examples

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32 Rayleigh-Benard Convection

33 Earth Structure

34 Convection in the Mantle

35 from: models convection in the mantle observed heat flow warm: near ridges cold: over cratons from:

36 From: "Dynamic models of Tectonic Plates and Convection" (1994) by S. Zhong and M. Gurnis

37 Earth s Plates

38 crust obvious from space that Earth has two fundamentally different physiographic features: oceans (71%) and continents (29%) from: global topography

39 Convergent Margins and Magma Genesis

40 MORB Genesis

41 Submarine Pillow Basalt Formation

42 Ocean Crust Age-Depth Relations

43 Simplified Geologic Time Scale