The Earth I. Introduction

B. Viscosity =ability to flow (=stickiness = thick = gooey)

- like adding flour........

b. Andestic Magma ~60% silica (like pudding)

P. c. Granite Magma (or rhyolitic) ~70% sil.

P. 3. Dissolved Gas – mostly steam, propels lava out

b. Ease of Escape =viscosity

P. 2. Andesitic + rhyolitic magma

P. A. Lava = molten ~2000 ° F ( ….... °C)….on surface

- creates harmonic quakes as lava rises

1. Basaltic –fluid (soupy)…flows fast

= sharp chunks of lava fall down as lava moves

2. Andestic - medium speed + distance

B. Gases = dissolved in magma until eruption

15% CO2 …. source of atmosphere

1. Fumeroles =-vent w/ only gas (sulfur oxides smells “bad”)
ex: Mt. Lassen (No. Cal.)

C. Pyroclastics = "fire + particles"

P. -released gas explodes lava …shattered…..thrown up through air

1. Ash - lava shattered into tiny shards of glass (rhyolitic)

2. Pumice -gas trapped in cooling rhyolitic lava rhyolite

P. 3. Cinders - “ “ “ “ basalt lava basalt

III. Volcano(es) = pile of ejected material, 6 types

P. - Lava flows – like river…very long......10’s miles to sea……

P. largest volc…….100 mls. across, 6 mls. high

P.
B. Cinder Cones

P. - steep pile of cinders (and bombs)…basalt

small <1/2 mile across, <1000 ft. high

P. 1^st stage: lava fountains = only 1 eruption (~1 week long)

2^nd stage: lava flows out of base

P. ex: Paricutin, Cal. Desert (near Baker)….. Basalt

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C. Dome –viscous lava (rhyolite), wart-like Rhyolite

P. ex. Mammoth to Mono, CA... several......

P. D. “Composite” Volcanoes = mix of lava and ash

- found at subd. zone ……

P. - beautiful… miles high (over 1 mil. yrs.)

P. Philipines (Mt. Pinatubo),

Dangerous due to high silica and gas:

P. ex. Mt. St. Helens....1980.....
1. Ash Fall - cold ash.... heavy (collapses roofs), bad to breathe,

P. ex: Pompeii

P. - go far and fast = on to valleys

• 
  - biggest killer! ex. Colombia, 1985; 20,000 killed 25 miles from volc.
  
• 
  - U.S. Danger: Mt. Rainier...Tacoma....dams......
  

P. 3. Glowing Avalanche = pyroclastic flow (“nuee ardente” in text)

P. - avalanche of hot ash and gas (~2000°F)

- fast (100 mph) and dense

P. ex: Mt. Pelee ….1902….30,000 dead.....only 1 survivor.....
4. Parasitic Cones -new volc.mtn on side of volcano ex. Mt. Shasta

5. Andesite Lava
P. 6. Caldera =huge "crater" due to collapsed volcano

after huge ash eruption (=rare)

P. ex. Crater Lake = 6 miles wide, rain….deepest lake….

ex. Long Valley caldera (Mammoth, CA).... Geo 32 class in Fall 201
ex. Yellowstone …. 3 eruptions in last 2 MY

P. ex. Santorini (Greek island)...... 3000 yrs ago.....Minoan......collapse

E. "Fissure" Eruption -rarest, largest vol.

P. 1. Rift Valley -basaltic lava ex. Iceland

P. 2. Flood Basalts -huge areas, only in ancient ….. very rare

- exposed by erosion over m.y.s........erosion....... now on surface

A. Dike - magma cuts across rock layers (= vertical)

-when eroded = reveals a wall

P. B. Sill -magma between layers (= horizontal)

P. C. Batholith =huge body of granite (=”pluton”)

E. Volcanic Necks -magma in vent  hard rock

P. ex: Shiprock, NM

ex: Morro Rock (Bay).... 12 in a row........Geo. 36 in fall 201
Note: These are not complete notes. They do not include important references to textbook. They also do not include the diagrams, which are the center of classroom instruction.


Igneous Rocks (Ch. )

A. Textures = appearance = size of crystals (xtl.s)

P.

1. Coarse Grained (phaneritic in text) = visible xtl.s (speckled)

2. Fine Grained (aphanitic in text) = invisible xtl.s (one color)

P. *lava cools on the surface fast

ex. basalt
3. Mixed (porphyritic in text) = big crystals in fine background

P. - magma started to cool slowly underground ….

and then moved up to surface as lava (fast cooling)

ex: andesite

P. 4. Vesicular =bubbles in rk. (volc.) = gas trapped as lava cooled

P. 5. Glassy = natural glass (no xtl.s) -due to fast cooling of rhyolitic lava

-solid (obsidian) or bubbly (pumice)

6. Pyroclastic

P. a. Tuff -rock made from loose ash

b. Welded tuff –hot = melts together …....

B. Composition- chemistry (= silica %)

1. Balsaltic Rocks =("mafic") =dark....black
-low silica (50%) , heavy rock

a. Gabbro-coarse grain, intrusive, magma (underground)

P. b. Basalt -fine grain (volc.)
…vesicular, lava cools on surface

[c. Peridotite -`ultramafic`= super-low silica, mantle rk.=olivine]

med. compos. (~60% silica)

P. a. Diorite -course gr. , from magma, “salt & pepper”
b. Andesite -fine grain = volcanic, gray, “mixed”
P. -subd. zn. composite volc.
ex. Andes, Cascades

3. Granite = (“felsic”), light(gray or pink), high silica (~70%)

c. Obsidian -glassy volcanic rock, black

C. Magma Crystalization -during cooling (2000° ---> 1000° F)

1. Crystal Size

in notes b. Intrusive – underground, slow cooling...yrs. = big xtls

1. Bowen's Reaction Series – important concept,

= shows order that minerals xtlize

- low silica min (dark) xtlize 1^st (hotter temp.)

- higher “ “ (light) “ later (cooler temp)

Temp. Melt Xtlize Minerals in order Mineral trends

Hot Last first Olivine Ca-Plag. Soft=less complex,

2000° F Ferro mags less silica= darker Biotite Na-Plag.
Ortho. Feldsar

Muscovite

Cool Hard=more complex

1000° F First last Quartz more silica= lighter

2. Partial Melting

- higher silica min. (qtz, feld.) melt first (low silica min. melt later)

- resulting magma is different (more silica, lighter) than original rock

ex: choc. chip ice cream................................
3. Magmatic Differentation
a. If magma moves up before whole rk. melts

= lighter magma (higher silica) results

=1st min. to xtlize =heavy =can sink

= bottom rock is more basaltic (heavy) ex; gabbro
and top is more granitic

III. Economic Deposits of Igneous rocks

B. Magmatic Differentiation = xtl settling ….gabbro

P. - Chromium (…..….), Platinum (…….........), Nickel (….........)

ex. So. Africa – ore mines
P. C. Pegmatites -last pocket of granitic magma to xtlize

-huge xtls= qtz, mica, gems (emerald, topaz)

P. ex: tourmaline in San Diego Cnty

D. “Hydrothermal” Deposits – hot groundwater from magma

P. -Si & metals dissolve into water through rk solidify (cool)

- then they “precipitate” (…........) in cracks = white veins

P. Uses: Gold................................., Silver..........................,

Zinc.............., Lead............................, Tungsten...............
P. b. Disseminated - ~1% copper throughout rock

uses: Copper ...........

P. ex. Ariz. & Chile mines (“open pit” mines)

E. Cinders: make red roads (ex. Cal. desert)

F. Pumice: uses= exfoliating skin
G. Obsidian: uses = arrowheads....................
H. Fertile Soils: volc. make best soils


Note: These are not complete notes. They do not include important references to textbook. They also do not include the diagrams, which are the center of classroom instruction.

Weathering and Soil (Ch. )

I. Weathering =breakup and decomposition

A. Mechanical Weathering = physical breakup, visable
P. 1. Ice wedging - freezing H2O expands 9%

(like bottle in freezer)P.

P. “Talus” = pile of rk at base of cliff
P. 2. Sheeting (Unloading in text) =pressure release ………erosion.
-rk. splits into sheets ……. joints parallel to surface (like onion).

P. “Exfoliation” = granite sheets peel off ex: domes in Sierras

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invisible
B. Chemical Weathering -decomposition (rot) of min. + rk by water

1. Hydrolysis =feldspar decomposition

P. ions (in water) change……form clay (washed away as mud)
P. 2. Solution =CaCO3 (calcite) dissolves in

carbonic acid (rain + CO2) … forms caves, etc…good

P. acid rain ….from coal burning...............................bad

3. Oxidation = iron rusting

P. -red color on rk surface or soil = hematite

*all 3 need water!

C. Rate of Weathering (chemical)

1. Jointing -more joints = faster w….

P.

P.

P. - corners eroded more ……..under wet soil (in past)

- common in granite with joints ex: Joshua Tree Ntl. Park

P.

3. "climate" (aver. weather) = most important

2) freeze/thawing

Ferromags
Felds.
Quartz
4. Parent Rock –depends on how stable min. are

P.

Stable (left behind as sand)

ex: beach sand from granite
II. Soils – needed for crops, farm animals, wood....…

A. Formation – amount & “fertility”…soil (affect on humans…)

1. Parent Rock + minerals

P. Ex: granite & sand vs. volcanic basalt & andesite

=bad fertility = good fertility

2. Time – longer = deeper soil

3. Slope

P. a. steepness - flatter = more H20  more soil.

b. orientation =direction it faces

c. Rainy side = more chem. W… ex. west side in Calif.

4. Climate Effect on Soils …most important

P.

a. Dry (desert) climates = mechanical weathering (wind, floods)

P. 1. Aridosol soils =tan ex. SW USA
2. Caliche = calcite layer on hillside

formed by evaporated grndwtr (like “scale”...........)

b. Moist Climate

P. 1. Dark Forest Soil =dark soil ex. No. USA

c. Hot Moist Climate "leaching"= infertile soil..... m.y.s

P.

1. Laterite = red clay soil ex. Tropical Rain Forests

P. 2. Bauxite -aluminum ore…......

P. 2. Rainforest destruction  farms with infertile soil

= abandoned after years erosion  red soil into rivers

* bad= huge environmental problem

Note: These are not complete notes. They do not include important references to textbook. They also do not include the diagrams, which are the center of classroom instruction.

Sedimentary Rocks (Ch. 7)

I. Sedimentary Rocks

A. Detrital Sed Rocks = also “clastic”

- made by rock particles that are buried, then lithified deep down
* visible to us = were uplifted and eroded
1. Characteristics

P. a. Size of particle = classify rocks

Particle	Wtr.Speed	Where (ex)	Sediment	Sed. Rocks
Cobble	Very Fast	Canyon
Pebble	Fast	River….	Pebbles	Conglomerate
Sand	Medium	Beach	Sand	Sandstone
Silt	Slow	Lake, Bay	Mud	Shale
Clay	Calm	Deep sea	”	”

* slower = finer sed.

C. Rounding – due to how much rolled around

*most sand is from mtn.s, not crushed up by waves on beach

a. Shale (mudstone) – half of all sed. rx.

P. 1. fine grain rk. (silt + clay)

2. deposited in sea + lakes = calm….

P. 3. easily eroded (= slopes + valleys)

ex. So. Cal. Freeways…..........

P. 4. Fossils + thin layers = crumbly

b. Sandstone
1. visible grains (medium)..... sandpaper

P. 2. deposited in beach, dunes

P. 4. harder to erode (forms cliffs+hills)

- landslide, volcano neck, fault.

e. Turbidites

P. no O2 then.... source of iron ore

1. BioChemical sed. Rocks -organisms make shells

plankton die shells sink to seafloor

a. Limestone - most common = 10% of sed. rx.

P. 1.Chalk -pure microsc. shells… white

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P. c. Coal -land plants buried in low O2 swamp --> M.Y.s

-fuel for industrialization ex. China, Applachians

P. -causes air & water pollution ….worst for global warming.......
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2. Inorganic Chemical Sed. Rocks -minerals crystalize directly from water
A. Evaporites -forms when water evapor. from sea or lake .

P. 1. CaCO3 (limestone) - 1^st to xtlize use: cement

B. Travertine -CaCO3 xtlizes from grnd. wtr.

- on surface or in cracks from springs “Mexican Onyx”

- Tufa = CaCO3 towers formed in lake...... ex: Mono Lake

P. C. Agate = layers of quartz
- deposited in empty spaces by groundwater................

- geode = hollow with xtls.

D. Lithification = sed. rk......MYs

E. Sedimentary Environments - different conditions = diff. rx.

P. Deep Sea → diat., chalk, shale

Turb. Curr turbidites

Lake & Bay  shale

Beach & Dunes  sandstone

Rivers, mudflows  conglomerate

Coral reef, shells  limestone

Dry lake  evaporites

Swamp coal

F. Oil

2. buried in low O2 = no decomposition

5. drill miles deep and pump oil out….

6. refine….. uses: gasoline, fuel, asphalt, tar, plastics

ex. L.A. Basin …., Persian Gulf
G. Natural Gas (methane) – formed in same way

Deeper = 2 – 5 miles deep

I. Metamorphism - any rock can “change form”… deep underground

B. Metamorphic Changes in minerals

P. 1. Texture =appearance

a. Foliation = striped or sheets, common
P. -xtl.s grow 90 to compression

- fol. is NOT original sed. layers!

P.

b. Non-Foliated = no stripes or sheets. All one color

P. a. Slate -dark, slatey cleavage Uses: shingles, chalkboard,

P. b. Schist –scales (or sequins), parallel mica xls. big

c. Gneiss -stripes of wh + blk, "zebra rock"

2. Non-Foliated Rocks = from 1-mineral sed.rock

P. a. Marble -coarse-grained calcite
- from limestone (CaC03) = HCl acid ….fizz
- soft = carving ex: Italy sculptures

- colors from impurities Use: floors

b. Quartzite -coarse gr. quartz xtl.s -from sandstone

c. Asbestos -fibrous, carcinogenic, fireproof insulation…..

-use: jade and soapstone carvings ex: central Cal. coast

500. 
     Metamorphic Occurrences
     1. Contact Metamorphism = next to magma (heat)
     P. a. Hornfels -fine grain, unfoliated, black rock ex: burnt cookies

     2. Regional Metamorphism = most important cause

     
     P. * a. Converging cont. crust huge mtn. ranges (now=Himalayas)
     

P. - highest in center

P. - low grade: micas glitter

graphite pencil leads

P. c. Continental Shields – huge meta. rk. areas = many collisions

P. d. Rock Cycle –rocks “turn into” other types by geol. processes