Chapter14

Chapter14 - Environmental Geology Chapter 14 Learn the...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Environmental Geology Chapter 14 Plate Tectonics and the Rock Cycle Rocks and Minerals Strategic Geological and Mineral Resources Environmental Effects of Resource Extraction: Types of Mining; Restoration Possibilities Conserving Geologic Resources Geologic Hazards Learn the processes associated with:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Earth is a layered sphere Crust - Cool, lightweight, brittle outermost film that floats on top of mantle; a.k.a. lithosphere Mantle - Hot, pliable semi-solid rock layer surrounding the core; less dense than core Core – 2-layer interior composed of dense, intensely hot radioactive metal (Fe)
Background image of page 2
Earth is a Layered Sphere Kilometers deep: 0 - 40 Crust 40 - 400 Upper Mantle 400 - 650 Transition Rgn 650 - 2700 Lower Mantle 2700 - 2890 “D” Layer 2890 - 5150 Outer Core 5150 - 6380 Inner Core Lower Mantle D” Layer Molten Outer Core Trans. Region of basaltic magma Solid Inner core Shallow Upper Mantle Crust = Lithosphere
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
NOVA Magnetic pole reversal occurs frequently (~every 200,000 yr) and takes only ~1,000 yr to complete The core generates a magnetic field enveloping Earth ± 97 - 99 % Main Field (from electric currents in the Outer Core) ± 1 - 2 % Crustal Field (from magnetized rock in the Crust) ± 1 - 2 % External Field (from ionized particles above Earth) NASA Earth’s Magnetic Field
Background image of page 4
Magnetic Anomalies What’s so important about magnetic pole reversals???? Fe molecules in the magma extruded along the ocean floor orient w/ the existing magnetic field…. .Switched poles = Fe molecules point opposite direction. Zones of opposite polarity were the first evidence of seafloor spreading and the basis for our understanding of plate tectonics
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Plate Tectonics Subduction Zone Spreading Center http://geology.wr.usgs.gov/docs/usgsnps/pltec/scplseqai.html
Background image of page 6
Plate Tectonics Other animations
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Plate Tectonics The crust is composed of plates that slide slowly across earth’s surface (~2-15 cm/yr) ± - ocean basins form where continents crack and pull apart; hot mineral-rich water is ejected into the cold surrounding sea and minerals such as Zn, Cu, Fe, Ag precipitate in "tower-like" formations Spreading Center Hydrothermal vent
Background image of page 8
Plate Tectonics The crust is composed of plates that slide slowly across earth’s surface (~2-15 cm/yr) ± - magma forced up through cracks in near plate borders forms mid-oceanic ridges and volcanoes Subduction Zone Mt St Helens
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Plate Tectonics Earthquakes are caused by grinding and jerking as plates slide past each other
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/22/2008 for the course BIOL 103 taught by Professor Brown during the Spring '08 term at VCU.

Page1 / 32

Chapter14 - Environmental Geology Chapter 14 Learn the...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online