CH 5-8 Flashcards
The breaking down of rock
Weathering
Breaks rock into smaller pieces
Physical Weathering
Breakdown rock chemically
Chemical Weathering
Oxidation, Dissolution, and Hydrolysis
Types of Chemical Weathering
Iron minerals rust. Olivine, biotite, pyroxene, & amphibole
Oxidation
Minerals dissolve. Halite
& Calcite
Dissolution
Water reacts with a mineral to form a new mineral. Muscovite & feldspar.
Hydrolysis
Frost Wedging, Exfoliation, Root Wedging, and Salt Wedging
Types of Physical Weathering
Water in crack freezes and expands, thus widening crack
Frost Wedging
Pile of angular rock at base of cliff
Talus slope
Rock peels off in layers. Result of removal of pressure
Exfoliation
Plant roots grow in cracks, widening cracks
Root Wedging
Sate crystals grow in cracks, widens cracks or holes
Salt Wedging
Form from pre-existing rocks
Sedimantary Rocks
Appearance of minerals and formation of rock
Texture
Bedding, Cross Bedding, Graded Bedding, Ripple Marks, & Mud Cracks
Sedimentary Structures
Layers in the sedimentary rocks
Bedding
Tells us paleowind direction
Wind Wind
—-> <——-
\\\\ ////////
Cross Bedding
Layers Based on Size. Tells us that water moved fast but slowed down.
……………..
ooooooooo
OOOOOOO
Graded Bedding
Gentle waves and/or gentle waves
Ripple Marks
Arid. Wet and then very dry.
Footprint
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V V V V V L___J
Mud cracks
-When a new fault forms
-Movement on pre-existing fault
-When magma moves
Earthquakes happen
-Anywhere
-Most occur at plate boundaries
Where earthquakes happen
Move through the earth
Body Waves
3 Seismographs for same earthquake. Look for 3 intersecting.
How to find epicenter.
P-wave & S-wave
The 2 types of body waves
-Travels fastest
First
Compression wave
Move material same direction as wave travels
P-wave (Primary Wave)
-Second to arrive
-More shaking and damage
-Shear wave
-Solids only
S-wave (Secondary Wave)
Moves material perpendicular to direction of wave travel
Shear Wave
-Move only on the surface
-Slow
-Last to arrive
-Shaking ~LOTS~Most intense
-Most damage
-L-wave
Surface Waves
Measure of destruction of earthquake
Intensity
I-XII (1-12)
Can change with distance to epicenter
Mercalli Intensity Scale
Measure of size of earthquake
Magnitude
Based on s & p waves
Inaccurate for large earthquakes
Scale of 1-10
Richter Scale
More accurate for larger earthquakes
Based on energy released
Based on displacement (amount of movement of fault)
Based on size of rupture (size of piece that moved)
Rock type
Scale of 1-10
Movement Magnitude
Surface waves are most destructive
Shaking
Soft sediment (Sand, gravel, mud) increases amplitude on seismic waves
Amplification of seismic waves
Ground flows like a liquid. Buildings sink or tip over
Liquefaction
Falling rock
Landslides
Caused by broken gas lines
Fire
Water in lakes, pools, rivers, etc sloshes back and forth
Water
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Seiche
Huge wave. Huge wavelength
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Tsunami
Recurrence Interval, seismic Gap
Earthquake Prediction
Average amount of time between events
Recurrence Interval
Large amount of time since last Earthquake
Area without an Earthquake OR longest time since earthquake
Seismic Gap
Change rock/minerals. No melting, no weathering, change caused by the agents of metamorphism
Metamorphism
How much metamorphism has ocurred
Metamorphic grade
High pressure &/or temperature
High metamorphic grade
Intermediate amounts of pressure &/or temperature
Intermediate metamorphic grade
Low pressure &/or temperature
Low metamorphic grade
The stuff coming out of a volcano
Volcanic Products
Resistance to flow
Viscosity
Forms a “mound”, flows slowly for shorter distances
EX: honey
High Viscosity Liquids
Spreads over large area, flows fast for longer distances
EX: water
Low Viscosity Liquids
Composition: Mafic
Rock Type: Basalt
Viscosity: Low
Basaltic Lava Flows
Pahoehoe
A’a
Columnar Joints
Pillow Basalts
Features of Basaltic Lavas
Ropy, taffy like lava flow. Looks like pile of rope or yarn
Pahoehoe
A blocky, angular, rubbly lava flow
A’a
Cracks form in lava flows due to shrinkage during cooling
Columnar Joints
Roundish (pillow shape and size) rocks of basalt. Formed underwater. Oceanic hot spot, mid ocean ridge.
Pillow Basalts
Composition: Felsic
Rock Type: Rhyolite
Viscosity: High
Rhyolitic Lava Flows
Piece
Clast
Rock
Lith
Rocks form from broken pieces of other rock
Clastic
Physical Weathering
Erosion
Transportation
Deposition
Lithification
5 steps in the formation of clastic
Removal of pieces
Erosion
Movement
-water -wind -ice -gravity
Transportation
Where pieces end up
Depostion
Process by which sediment becomes rock
2 parts: compaction and cementation
Lithification
Rocks precipitated out of water
Chemical
Life involved - shells, fossils, etc.
Biochemical
Life involved - carbon - plants
Organic
Shale
Sandstone
Conglomerate
Clastic
Limestone
Rock Salt
Chemical
Limestone
Biochemical
Coal
Organic
Too small to see/feel
Clay sized
All piece’s same size (clay) smooth
Well Sorted
Pieces in rock are not angular
Well Rounded
Different sizes. Rocks are angular
Poorly Sorted
Proximity to magma. Depth. Heat.
Crystalline Structure.
Temperature
Convergent plate boundaries –> <–
Depth. Crystalline Structure
Pressure
Near/at magma. Hot water. Depth.
Chemical composition. Crystalline structure
Hydrothermal Fluids
Parallel alignment of minerals. Regional Metamorphism.
Foliation
Minerals too small to see. Break into flat layers.
Slaty Cleavage
Wavy layers. Shiny.
Schistosity
Stripes
Gneissic Banding
Everything Else. No stripes. No layers. Contact Metamorphism.
Non-Foliated
Texture: Slaty Cleavage
Protolith: Shale
Composition: Quarts, clay minerals
Details: Smooth, flat layers
Foliation
Slate
Rock before metamorphism
Protolith
Which minerals
Composition
Texture: Schistosity
Protolith: Granite & More
Composition: Quartz, Feldspars, Muscovite, Biotite, Amphibole
Details: Shiny due to muscovite and biotite
Foliation
Schist
Texture: Gneissic Banding
Protolith: Granite & more
Composition: Quartz, Feldspars, Muscovite, Biotite, Amphibole
Details: Stripes
Foliation
Gneiss
Texture: Non-foliated
Protolith: Limestone
Composition: Calcite
Details: Fizzes in acid
Marble
Texture; Non-foliated
Protolith: Sandstone
Composition: Quartz
Details: Scratches Glass
Quartziite
Regional metamorphism and contact metamorphism
Metamorphic Environments
Larger area. Convergence. –> <–. Foliation.
Regional Metamorphism
Smaller area. Heat. Surrounding Magma. Non-foliated.
Contact Metamorphism.
Change of rocks/minerals
Metamorphism
If the rock melts it is _______
Igneous