Download Quiz Three (2:00 to 2:05 PM) - University of South Alabama

Quiz Three (2:00 to 2:05 PM)
UNIVERSITY OF SOUTH ALABAMA
GY 111: Physical Geology
Lecture 6: Plate Tectonics and Volcanism
Calbuco volcano (Chile)
(March, 2015)
https://www.reddit.com/r/photoshopbattles/comments/
33vhxp/psbattle_calbuco_volcano_erupting_on_22_april/s
Instructor: Dr. Douglas W. Haywick
Last Time
1. Crystal Chemistry (Crystallography)
2. Mineral Classification (“classes”)
3. The Silicates
Web notes 5 and 6
Crystal Structures:
CaF2
Source: http:\\staff.aist.go.jp
(Fluorite)
2+
-Ca
-F
Polymorphs:
Two minerals with the same chemical composition but
different crystal structures
e.g. Graphite (C)
Diamond (C)
Mineral Classification
Class
I
Name
Native Elements
Anion(s)
none
Examples
Dominant
Bond
Metals: Gold, Copper, Silver
Semi-metals: Arsenic (As)
Non-metals: diamond, graphite, sulfur
Metallic
Covalent
II
Sulfides
S-
Pyrite, Chalcopyrite, Galena
III
Oxides\hydroxides
O2- OH-
hematite, magnetite, limonite
IV
Halides
Cl-, Fl-
halite, fluorite
V
Carbonates
CO32-
calcite, aragonite, malachite
VI
Sulfates
SO42-
gypsum, anhydrite
VII
Phosphates
PO43-
apatite
VIII
Silicates
SiO44-
>3000 (i.e., most minerals)
Largely
Ionic
Silicate Classification
SiO4
4-
The basic silicate tetrahedra
Silicate Classification
The basic silicate tetrahedra (ball and stick)
Silicate Classification
Nesosilicates
(garnet, olivine)
(0 shared oxygen)
Sorosilicates
(1 shared oxygen)
Cyclosilicates
(2 shared oxygens)
Inosilicates
(pyroxenes)
(2 shared oxygens)
Inosilicates
(amphiboles)
(2 ½ shared oxygens)
Phyllosilicates
(micas)
(3 shared oxygens)
Silicate Classification
Tektosilicates
(quartz, feldspars)
(4 shared oxygens)
Today’s Agenda
1. Review of where volcanoes occur
2. Properties of magma/lava (viscosity)
3. Basic types of volcanoes
Web notes 6
Where Volcanoes Occur
Where Volcanoes Occur
Where Volcanoes Occur
1) Divergent P. B.
Where Volcanoes Occur
2) Convergent P. B.
1) Divergent P. B.
Where Volcanoes Occur
2) Convergent P. B.
3) Hot Spots.
1) Divergent P. B.
Divergent Plate
Boundaries
Hot
Divergent Plate
Boundaries
Rapid rise of
magma to surface
because of multiple
fractures and faults
(low resistance)
Magma (molten rock inside
the Earth) rises upwards
along fractures and fault as
plutons (inverted tear dropshaped blebs 100’s to
1000’s of m in diameter).
Why?....
Divergent Plate
Boundaries
Rapid rise of
magma to surface
because of multiple
fractures and faults
(low resistance)
Magma (molten rock inside
the Earth) rises upwards
along fractures and fault as
plutons (inverted tear dropshaped blebs 100’s to
1000’s of m in diameter).
Why?.... Buoyancy. Hot
magma is less dense than
cool country rock
Sometimes the magma can
make it all the way to the
Earth’s surface. Once there, it
is called lava and the point
where it is erupting from is
called a volcano.
Divergent Plate
Boundaries
http://www.ncgeology.com/Eno_interactive_webs/Geologic_Principles_Geologic_story.html
Convergent Plate
Boundaries
Convergent Plate
Boundaries
Subduction
35
km
Plutons rise at convergent plate
boundaries too….
… but they have to burn their way up.
This is not an easy trip to the surface.
Hot Spots
Hot Spots
Yellowstone
(continental hotspot)
Hawaii
(oceanic hotspot)
http://volcanoes.usgs.gov/yvo/images/2000-rbs-1.3ysrp_large.jpg
Properties of Magma/Lava
Properties of Magma/Lava
1.
Magma derived from just below the lithosphere (e.g., 100
km down) is hot (2000 °C) and very fluid (low viscosity)
Properties of Magma/Lava
1.
2.
Magma derived from just below the lithosphere (e.g., 100
km down) is hot (2000 °C) and very fluid (low viscosity)
Lava erupted at divergent plate boundaries and oceanic
hotspots has made it to the surface of the Earth quickly and
is still hot (up to 1800 °C) and fluid (low viscosity).
Properties of Magma/Lava
1.
2.
3.
Magma derived from just below the lithosphere (e.g., 100
km down) is hot (2000 °C) and very fluid (low viscosity)
Lava erupted at divergent plate boundaries and oceanic
hotspots has made it to the surface of the Earth quickly and
is still hot (up to 1800 °C) and fluid (low viscosity).
Lava erupted at convergent plate boundaries and
continental hotspots has made it to the surface of the Earth
very slowly. It is cooler (as low as 800 °C) and very
contaminated by country rock and water (high viscosity)
Properties of Magma/Lava
Volcanoes at Divergent
Plate Boundaries
Volcanoes at Convergent
Plate Boundaries
Types of Volcanoes
Types of Volcanoes
Types of Volcanoes
http://volcanoes.usgs.gov/Imgs/Jpg/Photoglossary/30424305-084_large.JPG
Cinder cone in Hawaii
Cinder cone
Cinder cone
http://www.discoverourearth.org/student/volcanoes/images/shield_volcanoes_big.jpg
Shield Volcanoes (Mauna Loa, Mauna Kea, HI)
Shield Volcano
Shield Volcano on Mars (Olympus Mons)
Lava Fountain
Lava stream
Lava Lake
Annoying eruptions
(but generally not
disasterous)
Fissure Eruption
Kilauea Hawaii
Mt. Taranaki
Composite Volcanoes
in New Zealand
Mt. Ruhapehu
Composite Volcanoes
in Japan (Mt. Fuji)
Mt. Ruapehu, New Zealand
Minor eruption
Phreatic eruption
Plinian eruption
From the international space station
Pyroclastic flows
Petal to the metal or else!
Air fall deposits (volcanic ash)
Today’s Homework
1. Download and read web notes 6
Next Time
2. Volcanic landforms and case studies
(AKA Death 101 – part 1) webnotes 7
GY 111: Physical Geology
Lecture 6: Plate Tectonics and Volcanism
Instructor: Dr. Doug Haywick
[email protected]
This is a free open access lecture, but not for commercial purposes.
For personal use only.