-Oxygeb abd Silicon account for about 75%
- Metallic elements iron, aluminum and the base elements account for the rest

-inorganic chemical compounds that are comined from the earths crust

-hardness

-cleavae (the way a mineral breaks in a certain direction)

-composition

-color

-luster (sheen)

3 types of rocks

(where they are from)

1.Igneous (from molten rock)

-magma- within the earth

-lava- molten rock on the surface

2. Sedimentary (from debris eroded from other rocks and other materials)

3. Metamorphic (rocks changed by heat and/ or pressure

--consists mainly of silicate minerals containing silicon, oxygen and metallic elements. (metallic elements determine mineral density)

-Less dense Felsic (rhyolite and andesite) minerals dominate the igneous rocks of the upper crust while more dense Mafic and Ultramafic minerals dominate those of the lower crust

-Molten tock may not reach the surface but still cool and form rocks

-If the magma reachest the surface it becomes lava and cools as a rock

-Granite (felsic minerals)

-Diorite (felsic minerals)

-Gabbro (mafic minerals)

-Peridotite (ultramafic minerals)

Extrusive rock types

-Rhyolite (falsic)

-Andesite (felsic)

-Basalt (mafic)

-cool slower so has larger crystals (minerals)

-the slower the cooling the larger the crystals

-sediments are laid down in layers and then compacted

-other minerals can hold the grains together (cementation)

-rocks derived from particles of other tocks = Clastic

-other are nonclastic such as chemical deposits or organic debris

-sandstone

-siltstone

-conglomerate

-mudstone

-claystone

-shale

-limestone

-dolomite

-chert

-evaporities

Common sedimentary rock types (organic)

-coal

-petroleum

-natural gas

Metamorphic rocks

-When rocks are exposed to extreme heat and/or pressure their characteristics change

-often become much harder

-Limestone becomes marble (example)

Structure of the earth

-Inner Core

-Outer Core

-Lower Mantle

-Upper Mantle

-Crust

Solid because of high pressure

-contains iron and nickel

-around 3500km in radius (earth is 6400)

Outer Core

-Liquid because it is at a lower pressure

-Lower and upper combine to be 2900 km thick

-Composed of Mafic minerals

-solid, hard

-Composed of Mafic minerals

-Soft just beneath the crust

-contact between brust and upper mantle= Mohorvicic discontinuity (Moho)

-Moho marks a change in density and is closer to the surface below ocean floors than land (8km compared to 40km)

-Ocean Crusts is entirely mafic, with basalt as lava flows, and gabbro in intrusions

-Continental Crusts occurs in two forms:

=a lower layer of dense

mafic rocks

=an upper less dense zine

of felsic rocks (like granite)

-outer earth zone, or shell, of rigid, brittle rock.

-Includes not only the crust but also the cooler, upper part of the mantle that is composed of brittle rock

-moves over the asthenosphere (soft under lithosphere)

-fragmented into lithospheric plates (or tectonic plates)

-7 major plates

-proposed that convection cells within the earth's interior drag the crust along

-plate tectonic movement

-1915 Alfred Wegener proposed that landmasses were once united (pangaea)

-over the past, land masses have formed and moved (continental drift)

-

-divergence (seafloor spreading)

-Convergence (collision)

Lateral (transform)

Plate divergence

-New crust is created and forced outwards from a rift

-upselling magma created new crust and younger rocks

-Graben (pulling apart, rifting)

-Horst (folding, compression)

-shallow continetal shelves are found beneath the ocean next to continental shields 

-Deep oceanic trenches are found adjacent to alpine belts

-ocean-land= subduction zone

-continental crust is lighter than oceanic crust

(oceanic crust is subducted)

-Subduction is fairly slow (2-3 cm per year)

-produced large earthquakes, volcanism, mountain ranges

-Nazca plate is the fastest at 7.4 cm per year

Oceanic-Oceanic plate convergence

-produces deep ocean trenches and many volcanoes

-eg. collision of north america and pacific plates (aleutian islands)

-produces thick land mass, earthquakes, but very little volcanism

-Eurasian (S) and Australian-Indian (N) Plate

-overturned fold

-recumbent fold

-overthrusting

(-overthrusting fault

-Thrust sheets)

-eg. san Andreas Fault

-Two plates are sliding past one another at different rates

-is accompanied bu frequent earthquakes

Sill

Dyke

Sill- magma that spreads out horizontally and doesn't erupt

Dyke- verticle release of magma that does not erupt

-molten rock extruded onto the surface

-magma- inside of the earth

-lava- outside the earth

-a volcano forms at the end of a vent

-often forms a crater

-may be described as explosive and non explosive

-volcanic eruptions also lead to lava flows, rock fragments, ash and gases

-active

-dormant

-extinct

-ocean ridges

-subduction zones

-other regions (eg. islands of Hawaii are on a "hot spot")

-acidic 

-slow moving mogma, often dark in color

-Basaltic 

-flowing stream of lava, often looks hot

-low in silica, high in iron and magnesium

-this produces fluid lava

-typical of mid ocean sea floor spreading

-less magnesium and iron, but more silica 

-this produces viscous lava (slow moving)

-typical of subduction zones

 -contains more gas and produces more violent eruptions

-destructive flow of debris

-projectiles

-small fragments

Composite volcano

(stratovolcano)

-Occur on subduction zones

-made up of layers of lava and pyroclastics/ tephra

-lava is acidic and viscous with gas and therefore explosive

-these volcanoes have steep sides and high elevations

-produces lahars (hardened mudflow of volcanic debris)

-mudflow comprised of volcanic debris

-melting of snow and ice combines with mud and ash

-flows downslope quickly

-once it hardens it is referred to as a lahar

Caldera

-after an eruption, lava and magma may no longer support the sides of the volcano

-the wall collapse

-the collapsed crater is known as a caldera

-occurs when acidic lava under pressure forms a steep-sided dome

-may form inside a crater

Cinder Cones

-made up entirely from pyroclastic debris

-remain small, forming during a brief period of explosive activity-> weather rapidly

Shield volcanoes

-form from basaltic lava

-lava is hot and fluid

-volcano build from successive sruptions of lava

-less violent

-large horizontal dimension (shield shaped)

-eg. Hawaii

-forms over hotspots

-a stationary point in the mantle that is very hot

-it is not a plate boundary

-a shielf volcano forms over the hot spot

-but the lithospheric plate moves so new volcanoes form

-water may enter the magma chamber resulting in a very violent eruption

-produces explosions called phreatic eruptions

-Geysers 

-Origin of the quake is the focus

-the point on the surface directly above the focus is the epicenter

-80% occur on the circum-pavific belt (pacific and Nazca Plates)

-also trans-eurasian belt

-fewer still at mid-ocean ridges

-Intraplate Earthquakes (very few and poorly understood)

-Measured using a seismograph

-smaller earthquakes after (after shock)

both from the same epicenter 

-rarely some form of prediction

-Richter scale introduced in the 1930's

-originally developed for only certain frequencies and distances

-opened ended from 0-8+

-logarithmic: 10x more for each number up

-

>8= 1 annually

7-7.9= 18 annually

6-6.9= 120 anually

5-5.9= 800 annually

Tsunamis

-Great sea wave or seismic sea wave

-these are generated by an earthquake epicenter being located on the ocean floor

-this displaces a large mass of water

-large openwater wave with large horizontal and little verticle

-becomes taller when they reach shallow coastal margins

-reach speeds of 1000 km/hr and 65 m tall

-exposed cliff-like face of the fault plane

-tend to be less than 1 meter but can approach height of 100 meters

-dislocated strata, open fractures, new scarps, and lines of crushes rock

-secondary features that are ofthen created are landslides, mudflow, and general earth movements

Anti

-the tops of the raised landmass 

Syncline

-The valleys created, but are filled with sediment

-weathering (rocks are broken down)

-Mass movement (gravity moves debris)

-Erosion (weathered debris is removed)

1. Gradational agents

2. Weathering

1.-running water

-glaciers

-wind

-coastal waves

-chemical solution

2.physical/ mechanical

-chemical

-biological

-rocks destroyed by imposed stresses

-no chemical changes

-rocks are broken apart

Thermal expansion

-growth of salt crystals in spaces in rocks

-in arid regions, as water evaporates

-minerals are chemically altered

-some are resistant (quartz)

-others are not (limestone once chemically weathered, can dissolve)

3 types

hydrolysis, oxidation & carbonation

maximum angle that loose material forming a slope can maintain without slipping

-it is a balance between gravity and friction

-the friction is between the particles

-if water is added, the friction is reduced and then the slope may fail

-solid rock could be 90 degrees

-loose material and soil 13-24 degree

-slow motion of soil layer

-due to alternate freeze/thaw or wet/dry cycles

-also due to needle ice

Solifluction

-a form of creep

-soil and rock are saturated and slow downslope

-common in subpolar regions

-drainage is inhibited

flow movement

-earth flow- saturated slope materials flow downlslope

-more rapid than solifuction

-flow is lobe-shaped

-landslide occur on steep slopes

-very fast movement (eg. triggered by earthquakes)

fall movements

-free-fall of pieces of rock

-accumulate at the base of the slope

-talus cone

-large fragments lie at an angle of around 35 degrees

-high lattituse or high altitude environment on the perimeter of a glaciated region

-20-25% of the land surface is periglacial

-50% of Canada and 80% of alaska is periglacial

-permanently frozen ground (soil and rock)

-between 15cm to 5 meters below the surface

-permafrost table is the upper surface of the permafrost

-freezes and thaws annually

-form when rock and soil remain below 0 C for at least 2 years 

below the permafrost table, the frozen ground may be as thick as 1200 meters

-continuous (thick and unbroken)

-discontinuous (think with gaps of unfrozen ground)(gaps of unfrozen ground= taliks)

-alpine (occur at high elevations at lower latitudes)

-this leads to slopes being covered in large pieces of rock 

-also reffered to as felsenmeer or block fields

-probably a slow gradual process

-vertical movements

-moves rocks to the surface

-large pieces moved up more than small ones

-horizontal movements

-also large pieces moved move than small ones

-fine in the middle, coarser on the edges 

-form because of uneven ground produced by heaving

-small particles accumulate in the center, large particles roll the sides

-stone stripes form on slopes of 7 degrees or more

-hill with a core of ice, derived from a bulge in the permafrost table

-water in the active layer freezes and adds to the bulge

-therefore can get bigger over time

-if ice melts, the hill collapses leaving a crater