2024 Lecture W 8, GEOL 246, Ch 9-10, Metamorphic & Earth Resources PDF

Chapters 9-10 Metamorphic Rocks & Earth Resources  GEOL 246: PHYSICAL GEOLOGY Lecture Schedule & Quizzes (Subject to change) The theory part of this course consists of lecturenotes which will be posted on the course home page in Bright...

Chapters 9-10 Metamorphic Rocks & Earth Resources  GEOL 246: PHYSICAL GEOLOGY Lecture Schedule & Quizzes (Subject to change) The theory part of this course consists of lecturenotes which will be posted on the course home page in Brightspace. You will be assessed in Quizzes and the Final Exam. Week Textbook # Chapters Topics 1 1-2 Introduction to Geology & the Universe 2 13-14 Historical Geology & Geologic Time (Quiz 1: ch. 1, 2): 5% 3 3 Plate Tectonics (Quiz 2: ch. 13, 14): 5% 4 4 Minerals (Quiz 3: ch. 3): 5% 5 5-6 Igneous Rocks and Volcanoes 6 7 Weathering & Erosion (Quiz 4: ch. 4, 5 & 6): 5% (Lab test 1): 5% 7 8 Sedimentary Rocks 8 9-10 Metamorphic Rocks & Geol. Resources (Quiz 5: ch. 7): 5% (Quiz 6: ch. 8): 5% 9 11-12 Structural Geology & Earthquakes (Quiz 7: ch. 9, 10): 5% Maps & Cross Sections (Quiz 8: ch. 11,12): 5% (Lab test 2): 5% 10 D2L Terrestrial Depositional Environments (Part 1- Fluvial & Eolian) 11 No class READING WEEK 12 8, D2L Terrestrial Part 2, Deltas, Transitional Deps. Envs., & Marine Envs. (Quiz 9: Terr. Dep. Envs. Part 1.): 5% 13 19 Surface Water (Quiz 10, Transitional & Marine Envs.): 5% 14 19-20 Groundwater 15 15 Canada Geol. & Earth History (Lab test 3): 5% 16 Final Exam: Cumulative, mainly covering ch. 19, 20, and 15, 10%  GEOL 246: PHYSICAL GEOLOGY Lab Schedule & Tests During these labs you will have the opportunity to handle rock samples and minerals as well as creating geological maps and cross-sections. You will be assessed in each lab session. Week 3 Lab tests (15%) and Lab Activities (25%)= 40% total mark for Lab activities 1-2 Mineral Identification- Introduction (3%) 3 Rock Identification (Igneous & Metamorphic) (1%) 4 Rock Identification (Sedimentary Rocks) (2%) 5 Reservoir Properties of Sedimentary Rocks (2%) 6 Lab Test 1 (5%) 7 Isopach Maps (3%) 8 Acheson Corals Leduc Fm (3%) 9 Pay Maps (3%) 10 Lab Test 2 (5%) 11 READING WEEK 12 Structure Contour Maps (2%) 13 Stratigraphic Cross-Sections (3%) 14 Structural Cross-Section (3%) 15 Lab Test 3 (5%) Chapter 9: Metamorphic Rocks Chapter 10:Earth Resources 14 mins. https://www.youtube.com/watch?v=HUydPhIaQQU  Metamorphic Rock Are formed when pre-existing rocks of different types (sedimentary, igneous, or metamorphic) are recrystallized without melting into a new texture & new minerals’ assemblage. Are result of solid-state recrystallization of “parent rock” due to raised temperature and/or pressure conditions. Proteozoic Windermere Group slate beside the Trans-Canada highway near to Golden, BC  What processes can raise the pressure and temperature of the crust? Gneissic rocks of the “Vishnu Schist” near the bottom of the Grand Canyon, Arizona  Metamorphic Grades Rocks evolve through a sequence of Metamorphic Grades: 1 MegaPascal = 10 bars  Tectonic Processes and the creation of heat, pressure, and active fluids Tectonic processes create regions of high heat flow and high pressure Why do cooler conditions extend well below surface along subduction zones?  Contact Metamorphism Heat The temperature increases ~30o C per kilometer of depth This rate of change is known as the geothermal gradient But as is evident from the previous diagram, this varies significantly in different tectonic settings At temperatures between 150-200oC, i.e. Temperatures are particularly high depth of ~8 km, clay minerals become in the vicinity of magma bodies. unstable and recrystallize into chlorite or mica  Fluid transport facilitates Recrystallization In addition to heat and pressure, chemically active fluids transport heat and promote recrystallization Hydrothermally altered rocks Heat in contact metamorphism recrystallizes country rock  Pressure Lithostatic stress Limestone Marble What geological mechanism can produce directed stress? Directed stress  Pressure causes most foliation forms Newly formed metamorphic Original texture (e.g., minerals (e.g., mica), forced to sedimentary layering) grow perpendicular to the main pressure direction Pressure Pressure Steven Earle foliation direction  Foliated Texture Slate Fractures along parallel planes due to invisible aligned micas Shale is the parent rock Phyllite Foliated texture formed due to Parallel or wavy fabric, surface directed stress associated with sheen due to micas regional metamorphism Schist Parallel to sub-parallel alignment of visible mica crystals Gneiss Minerals (in this case feldspar and amphibole) segregated into bands Metamorphism at a continent-continent convergent boundary Foliation formed due to directed stress in regional metamorphism  Metamorphic Grade Metamorphic index minerals provide. an indication of the metamorphic grade IMPORTANT! Various Metamorphic Products  A block of phyllite in Yoho National Park, BC Steven Earle The original bedding is still visible as compositional layering (dark and light layers), and is at an angle to the plane of phyllitic foliation (and rock cleavage). What was the main pressure direction on this rock during metamorphism? Types of Foliated Rocks  Important Nonfoliated Rocks! Nonfoliated rocks may develop during regional or contact metamorphism Marble Quartzite Metaconglomerate Hornfels Anthracite  Non-foliated metamorphic rocks Anthracite Hornfels Marble Quartzite Metaconglomerate Are all of these rocks necessarily the result of contact metamorphism? Types of Nonfoliated Rocks Original sand grains Original clasts likely may be visible visible  Limestone => marble due to contact metamorphism Impure limestone in contact with silicate-rich pluton forms wollastonite and carbon dioxide gas.  Metamorphic Facies The relationship between mineral assemblage and metamorphic grade is expressed by Metamorphic Facies Describe the pressure and temperature conditions that prevail where Volcanic Arc metamorphism occurs. Explain. Metamorphism is closely linked to Plate Tectonics Identify where you would expect to find each of the following types of rock: blueschist, hornfels, greenschist, gneiss and migmatite. Explain why you picked these sites.  Chapter 10: Earth Resources  The Crust The crust contains metals, building stone, minerals, and sources of energy Giant mining Look around you and machines at a coal mine in identify at least five Wyoming things produced with geologic resources.  Geologic Resources The nonliving materials mined to maintain our system of industry and quality of life  Oil Oil is composed of carbon that is primarily derived from buried plankton. Source Beds, Reservoir Beds, and Oil Traps Why is shale a good cap rock while sandstone is a good reservoir rock? The World’s Oil About 77% of the world’s oil has already been discovered. Most petroleum is found in a few large fields, and most fields are small. As exploration progresses, the average size of discoveries decreases. What does the term “peak oil” actually mean?  Consumption Vs. Discovery Discoveries of oil (blue) have been dropping since the 1960s. The red part of the graph indicates predicted future discoveries. The orange line indicates annual consumption of oil. The trend of these data (running in opposite directions) indicates that eventually we will run out of affordable oil. This video clip highlights the facts that affect our industry by and large. 14 mins. https://www.youtube.com/watch?v=xMQUGSrnbP8 … 30% already produced and used.  Coal Coal is a fossil fuel that is found in stratified sedimentary deposits The largest coal reserves are in the United States, Russia and China. There is a lot of coal in the world, but its use causes smog, acid rain and air toxicity and, most significantly, it is the major contributor of the carbon dioxide that causes climate change.  Canada’s Coal Most of Canada’s coal resources are in the west, although the first coal mines were in the Maritimes  Types of Coal Peat (dense layers of warm, humid Lignite (brown coal) wetlands vegetation converted (plant remains still visible) by microorganisms) Bituminous (soft coal) (biogenic sedimentary rock) Anthracite (hard coal) (noncrystalline metamorphic rock) What has to happen to coal-bearing rock to convert bituminous coal into anthracite?  Nuclear Power Nuclear power plants provide about 17% of the world’s electricity ~15% of total energy production in Canada (~ 8% in the US, ~80% in France) >400 nuclear power plants around the world (22 in the Canada)  Debate Construction of nuclear power plants in North America were at a virtual stand- still for about three decades. Why is this the case?  Renewable Energy Renewable energy (mostly hydro) accounts for 24% of Canada’s energy supplies Solar Power Wind Power Bioenergy Geothermal Energy Hydroelectric Power Ocean Energy  Renewable Energy Consumption Describe and explain some of the differences between Canadian and US energy consumption figures?  Solar hot-water panels at the Drakes Landing housing Steven Earle complex in Okotoks ,Alberta. The panels provide hot water but also much of the space-heating needs of the residents. Thermal energy is stored in an underground storage system. Visit http://www.dlsc.ca/ to find out more about this project.  The three Fundamental Types of Energy Solar Energy – Electromagnetic radiation, origin: nuclear fusion inside the Sun’s core Geothermal Energy – Heat: origin: the nuclear energy stored in the Earth (e.g., in uranium) Tidal Energy – Kinetic energy: origin: the gravitational effects of the rotation of the Earth and Moon around the Sun How is hydro energy a type of solar energy? What is the ultimate source of the nuclear energy stored within the Earth? Revelstoke Dam, BC  Non-renewable Energy Resources Oil, Coal, Natural Gas, and Uranium account for 76% of energy consumption in Canada (The rest is Hydro: 21%, Other renewables: 3%) Most of our Energy comes from Nonrenewable Resources Where are oil and gas found in Canada? What about uranium?  Usage Fossil Fuels, principally petroleum and natural gas, provide energy that powers society, but Hydro is also very important in Canada What are some of the environmental implications of fossil fuel use?  Nonmetallic Mineral Resources Mineral Resources Include Nonmetallic and Metallic Types  Metallic Mineral Resources Mineral deposits: the profitable assemblages of ore minerals + gangue (non-ore minerals) ~40 different metals are produced by mining and smelting A typical ore mineral is chalcopyrite: CuFeS2. Copper is recovered in a smelter by separating it from the iron and sulphur  The four processes forming ore minerals 1 2 3 4  1) Magmatic segregation Processes This diagram shows a number of processes that take place within a magma chamber, and many other processes that take place within the rocks surrounding the magma. Consider how the presence of the magma is critical to these other processes. 2) Hydrothermal activities The diagram to the left shows a black smoker close to a sea-floor spreading centre. Hot water, circulating through cracks in relatively new sea-floor basalt is flowing from a sea floor vent into cold ocean water. The resulting tiny sulphide mineral crystals look like black smoke. Why might the sudden change in conditions (at the sea-floor vent) lead to the dramatic precipitation of these minerals? 3) Residual Mineral Deposits: weathered or leached What is the importance of the water table to this process?  4) Sedimentary Mineral Deposits: placer ores, evaporites, banded iron ores Most iron formation formed on the deep ocean floor during the period in Earth’s history when the atmosphere and oceans were evolving from oxygen-poor to oxygen-rich. Why do iron minerals form from dissolved iron when the water becomes more oxidized? Deposits of relatively heavy and insoluble minerals, such as gold or diamonds, are concentrated in streams or on beaches at locations where currents slow. Identify the tectonic conditions that may be responsible for the overall environment depicted in this figure.  COPYRIGHT Reproduced and used in accordance with the fair dealing provisions in section 29 of the Canadian Copyright Act for the purposes of education, research or private study. Further distribution may infringe copyright. Copyright © 2014 John Wiley & Sons Canada, Ltd. All rights reserved. Reproduction or translation of this work beyond that permitted by Access Copyright (The Canadian Copyright Licensing Agency) is unlawful. Requests for further information should be addressed to the Permissions Department, John Wiley & Sons Canada, Ltd. The purchaser may make back-up copies for his or her own use only and not for distribution or resale. The author and the publisher assume no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information contained herein.