(Earth’s inner core is solid and made of Iron & Nickel)

GRANITIC – rock that hardens, flows to the surface, light, takes a long time to cool.

(Continental crust generally)

BASALTIC- Dense (heavy), dark rock (Ocean floor generally)

(Lighter plate always breaks on top)

SUBDUCTION- when one plate plunges below the other into the asthenosphere to be recycled.

ASTHENOSPHERE- partially molten rock that helps move the tectonic plates.

CATASTROPHISM- rejected theory of mountains occurring over night, and canyons suddenly

breaking and making continents.

DIVERGENCE IN TECTONIC PLATES:

(Molten rock fills in the gap with lava)

(‘Subduction Zone’ creates pressure and lava pushes upward to create volcanoes)

TRENCH- deepest part of earths crust…….

3 TECTONIC PLATE MOVEMENTS

PANGEAEA

Laurasia-(North) North America, Europe, Asia

Gondwana-(South) South America, Africa, India, Australia, Antarctica

‘Alfred Wegener’ a German climatologist proposed the theory of continental drift.

NORMAL FAULTS

1.) Dip-Slip Faults (Tension)

2.) Reverse Fault (Compression)

3.) ‘over’Thust Fault (Compression)

4.) Graben Fault

5.) Horst Fault

STRIKE-SLIP FAULT

OBLIQUE FAULT

FAULT- a line of fracture in the earths surface where movement of rock has taken place.

SEISMOGRAPH- a sensitive instrument that can record seismic waves.

FAULT SCARP- (Fault Escarpment) topographic escarpment of an uplifted block where

vertical displacement of bedrock offsets the land surface.

PALEOMAGNETISM- the origentation of magnetism locked into rocks as they solidify,

recording the direction to magnetic North at the time of cooling.

ISLAND ARCS- Where two ocean plates meet, the older denser plate will subduct and the

less dense oceanic plate will override it, sometimes creating volcanoes between continents &

oceanic trenches. (Aleutian Islands, Alaska)

CONTINENTAL COLLISION-when two continents or land masses fuse or join together,

creating a new larger landmass. (India – Asia)

TRANSFORM FAULTS-fracture zones, common alongside mid-ocean ridges. Cross-hatched

plate boundaries along which lateral movement takes places.

HOT SPOTS-stationary molten masses that do not move with the lithospheric plate.

(Hawaiian Islands)

(‘Loihi’- now developing under-sea, the next Hawaiian island)

GREAT RIFT VALLEY- (Eastern AFRICA)

CONTINENTAL SHIELDS-ancient crystalline rock areas, core areas worn down by

hundreds of million years of erosions, far from active plate boundaries, and historically

stable. (Canadian, Scandinavian, and Siberian Shields)

ACCRETION-adding numerous chunks of crust to the main continent by collision.

MICROPLATE TERRANES-adding segments of crust, two plates merging into one.

(Alaskan Plate & North American Plate, 200 million years ago)

PALEOGEOGRAPHY-the study of past geographic environments.

-‘PALEOMAP’ – simplified models of the regions & times they represent.

- Today we are in the;

‘Holocene Epoch’ (Last 10,000 years)

‘Quaternary Period’ (Last 1.6 million years)

‘Cenozoic Era’ (Last 64 million years)

VOLCANOES: mountains or hills formed by an expulsion of molten material.

CAN HAPPEN: 1.)Divergence Zone (Iceland, Mid-Atlantic Ridge)

2.)Convergence Zone (Cascades, Paricutin)

3.)Hot Spots (Hawaiian Islands)

CALDERA-a volcano that expels so much eruptive material that its summit collapses

into its emptied magma chamber, forming a large crater.(Crater Lake & Yellowstone NP)

CINDER CONE (Example: Paricutin)

-Tipped Cone

-Formed by pieces of solidified lava

-EXPLOSIVE

COMPOSIT (STRATO) VOLCANO (Example: Mount Fuji)

-Alternating Layers

-May develop secondary cones

-EXPLOSIVE

LAVA DOME (Example: Krakatoa)

-Lava sets up quickly producing explosions

-Somewhat EFFUSIVE

-Highly EXPLOSIVE

SHIELD VOLCANO (Example: Hawaiian Islands)

-Wide/Spreads before set-up

-EFFUSIVE

LAVA PLATEAU (Example: ‘Columbia-Snake Plateau’,WA,OR,ID)

-Lava flows from ‘fissures’ (cracks)

-Forms horizontal or flows down slope

-EFFUSIVE

VOLCANISM-the rise of magma & its cooling at the earth’s surface.

GEOMORPHOLOGY-a major subfield of physical geography, seeks explanations for shape,

origin, spatial distribution, and development of terrain features.

+ Mechanism that uplift portions of earths surface gain their energy from ‘Igneous Processes’ or

‘Tectonic Processes’.

GRADATION PROCESSES-the many surfacial processes that act to wear away high places &

fill in low places.

AGGRADATION- the filling in of low places that have been eroded from higher landforms.

RELIEF- the difference in elevation between the highest & lowest points in a specified area.

DEGRADATION-weathering & erosional removal.

MAGMA-molten rock ‘WITHIN’ the lithosphere.

- SILICA-RICH – cool while molten, thick/resistant to flowing.

- MAFIC-RICH – high melting point (hot), iron-rich minerals, less viscous, flow readily.

LAVA-molten rock that has reached the ‘surface’.

- BASALTIC LAVA – hot, more flow, less viscous, tends to vent gases readily.

FISSURE FLOWS-orginate from deep cracks in the crust. (lavas of the sea floor)

PYROCLASTIC MATERIALS-(tephra) molten material that solidifies in flight from an

eruption.

+ CAN CAUSE

1.) Volcanic ‘BOMBS’

2.) Cinders

3.) Volcanic Ash – can be the size of sand to fine dust.

LAVA FLOWS- layers of molten rock that flow over the land surface, cooling and solidifying.

Basalt lava is the most common.

- Pahoehoe – liquid lava that flows and cools with a ropy surface.

- aa – slow moving, piled-up, sharp edged, and jagged blocks.

FLOOD BASALTS-some continental areas covered with enormous accumulations of hundreds

of overlapping lava flows.

(form areas of ‘BASALT PLATEAUS’ topographically high areas of low relief.

PLUG DOME- volcanoes extruding taffy-like lava (rhyolite), that fills the cone, generally

without flowing beyond it.

INTRUSIONS- bodies of magma beneath igneous rock that cooled and solidified beneath the

surface.

PLUTONS- intrusive igneous bodies that eventually cool and solidify at great depth.

STOCK- (small) irregularly shaped intrusion. ( >100 km.,40 mi. )

BATHOLITH-(large) intrusions, complex mases of solidified magma, usually granite, core of

many mountain ranges. ( <100 km.,40 mi. ) (U.S. West & Great Smokey Mountains)

LACCOLITH- develops when magma flows horizontally between rock layers, bulging layers at

the surface up-ward, MUSHROOM-SHAPED. ( La Salle Mountains, Utah )

SILL-horizontal structure, parallel to and interbedded in pre-existing rock.

DIKE- lava ‘wall’, which originally filled a fracture.

NECK- remnant of solidified magma in the vent of an extinct volcano. (Devils Tower, WY)

DIP- the inclination of rock layers or other rock surfaces.

STRIKE- the compass direction of the outcrop rocks. (EAST – WEST STRIKE)

COMPRESSION-tends to shorten or thicken crust.

TENSION-tends to fracture or stretch crust.

COMMON ELEMENTS OF EARTH’s CRUST

OXYGEN = 46%

SILICON = 27%

ALUMINUM = 8%

IRON = 5%

TYPES OF ROCKS

1.) Igneous Rock – formed from the cooling of molten rock.

2.) Sedimentary Rock – rocks & other material that undergo weathering.

(CALCIUM CARBINATE & PRESSURE turn sediment into Sedimentary Rocks)

- Detrital – derived from the remains of pre-existing rocks that have been eroded. All

are ‘Clastic’ (made up of fragments)

- Chemical – result of precipitation & material dissolved in water.

3.) Metamorphis Rock – igneous or sedimentary rocks that change appearance or composition.

‘4.’)FELSENMEER- “sea rock” , a boulder field.

LAVA = EXTRUSIVE -------------> VOLCANIC ROCK

MAGMA = INTRUSIVE -------------> PLUTONIC ROCK

COLUMNAR JOINTING- cooled over a very long time, hexagonal fractures caused by lava

shrinking as it cools. (Devils Tower, WY)

HOW ICELAND WAS FORMED: a meteor of good size crashed into the Mid-Atlantic Rift

breaking the thin seal and exposing the asthenosphere, magma then poured out creating the

island Iceland. Volcanic activity still happens on a daily basis.

FOLDING: irreversible deformation which rock undergoes due to tectonic stress.

SYNCLINAL VALLEY & ANTICLINEAL VALLEY

(Oil is commonly found at the center of Anticline Valleys trapped under fine material)

TYPES OF MASS WASTING

Fall-includes rock fall and debris fall

FORMS TALUS SLOPE – (Big)

SCREE SLOPE – (Small)

Slump-shearing of material along an arced line

of slippage, the ‘slump block’ has a rotation

movement, and often remains intact.

(Trees would tip in a backward fashion)

Slide-often caused by water entering the rock/soil

structure, resulting in a loss of surface tension

and added weight.

(Trees would point straight outward)

Flow-the matter in a slope becomes saturated

and results in ‘slope failure’

DEBRIS FLOW – ‘solid’ material behaves like a liquid.

MUD FLOW – following a heavy downpour there is increased runoff.

Runoff can pick up so much small (clay & silt) particles that flow becomes mud.

Creep-due to freeze-thaw activity in the soil.

(causes trees to bend in a ‘J’ form)

SOLIFLUCTION-(soil-flushing) land shape being moved by freeze-thaw, low vegetation.

PERMAFROST-any rock or soil material that has remained below 32° F continuously for two

or more years. The two-year minimum stipulation is meant to exclude from the definition the

overlying ground surface layer which freezes every winter and thaws every summer (called the

"active layer" or "seasonal frost").

ICE WEDGING-When water infiltrates fractures in rock and freezes, the force of expansion is

great enough to break the rock into smaller pieces.

WEATHERING-combined action of all processes where rock is decomposed and disintegrated

at or near the earth’s surface. (the processes of rock break-up)

-MECHANICAL WEATHERING – (disintegration of rock)

-Freeze-Thaw/Heaving -Unloading -Salt Crystals

-CHEMICAL WEATHERING – (decomposition of rock)

-Hydration -Carbonation -Karst Topography -Oxidation

-BIOLOGICAL WEATHERING – (plants) roots ect., (lichens) chemical/physical, (animals)

grazing, burrowing, agriculture, forestry, ect.

MASS WASTING-combined effect of gravity and forces of weathering.

GEOMETRY OF ROCK BREAK-UP

-GRANULAR DISINTEGRATION – rock (usually course texture) falls apart grain by grain.

( when you pick up a rock & it crumbles in your hand)

-EXFOLIATION – surface peeling of rock layers, effect or mechanical or chemical weathering

or uploading.

-JOINT-BLOCK SEPERATION – breakage along fractures and bedding joints already there

from (cooling, magma, crustal movement, and sedimentary processes)

-SHATTERING – disintegration along new fractures of breakage in otherwise massive, strong

rock. Forms very angular pieces with sharp corners & edges.