Download Life its not easy

Alarcon 1
Rock cycle: term given to the long-term ‘recycling’ of mineral material
from one kind of rock to another. The rock cycle is an ongoing process,
beginning as rocks are pushed up by tectonic forces, and eroded by wind
and rain. The eroded rocks travel by wind or moving water until they are
deposited, settling into layers. Additional eroded rocks may bury these
layers until heat and pressure change the underlying layers to metamorphic
rock. More eroded rocks may squeeze and press the layers into sedimentary
rocks. Rocks can also be sunk down into the lower layers of the earth by
plate tectonic processes. Buried rocks may also melt and recrystallize into
igneous rocks. Metamorphic, sedimentary, and igneous rocks may then be
pushed up by tectonic forces, starting the rock cycle again.
The water cycle and the rock cycle are closely interlinked, as if they were
partners in a long marriage. Everything really is connected to everything
else. RC is a model that describes the formation, breakdown, and
reformation of a rock as a result of sedimentary, igneous, and metamorphic
processes.
The creation and movement of rock around the earth is the rock cycle. It is a
very slow process that happens over millions and millions of years.
Radioactive melting: material that emits radiation energy in the form of
alpha, beta, or gamma particles or rays – all of which can damage living
tissue.
Convection: energy transfer through the vertical circulation and movement
of fluids, such as air due to density differences.
Magma rising: melting of solid rocks to form magma is controlled by three
physical parameters: temperature, pressure and composition.
Crystallization: when magma cools, crystal form because the solution is
super-saturated with respect to some minerals if the magma cools quickly,
the crystals do not have much time to form, so they are very small. If the
magma cools slowly, the crystals have enough time to grow and become
large.
Consolidation:
Cooling:
Venting:
Uplifting / Faulting: is the process by which deeply buried rocks are returned
to the Earth’s surface by tectonic forces.
Folding: the bending of crustal rocks by compression and/or uplift.
Weathering: the physical and chemical disintegration of rock that is exposed
to the atmosphere.
Mechanical wxg: actions or things that breakdown earth materials
Alarcon 2
Frost wedging: fragmentation of rock due to expansion of water
that freezes into ice within rock openings.
Thermal expansion and contraction: repeated heating and
cooling of materials cause rigid substances to crack and
separate.
Exfoliation: wxg process in which curved layers peel off bedrock
in sheets. This process commonly occurs in granite and related
intrusive rocks after overlaying rock has been removed, allowing
the body to expand slightly. Also referred to as unloading.
Salt wedging: rock disintegration caused by the crystallization of
salts from evaporating water.
Insolation: Alternate heating and cooling, causes rock to expand
and contract, causes stress failure. Common in deserts.
Abrasion: moving sediments or rock sections can break off
pieces from a rock surface. The sediments can be moved by
wind or water and the large rock sections by gravity.
Freezing: water enters, cracks, freezes and expands by ~9%
Warming
Biological wxg: roots in cracks physically prise the rock apart; humic
acid produced by plants attacks rocks chemically.
Plant growth: as plants such as trees send out root systems, the
fine roots find their way to cracks in the rocks. As the roots
increase in size, they force the rock sections apart, increasing
the separation and weathering (plant wedging).
Chemical wxg: the chemical decomposition of rock by the alteration of
rock-forming minerals.
Dissolving (dissolution): water, often containing acid from
dissolved carbon dioxide, will dissolve materials from a rock
body leaving cavities in the rock. These cavities may generate
sinkholes or cave features.
Oxidation: this type of chemical wxg is what causes rust. Oxygen
that is dissolved in water reacts with the minerals that contain
iron. This will turn the rock and soil around it a brownish red
color. It will also get weaker and crumble once it has rusted.
Hydrolysis: this type of chemical wxg usually happens in silicate
materials, turning them into clay minerals with the introduction
of water. Water comes in and breaks changing the structure of
the mineral.
Carbonation: a process in which carbon dioxide in water reacts
with carbonate rocks to produce a very soluble product (calcium
bicarbonate) which can readily be removed by runoff or
percolation, and which can also be deposited in crystalline form
if the water is evaporated.
Alarcon 3
Hydration: is the absorption of water into the mineral structure.
Hydration expands volume and also results in rock deformation.
Mass wasting:
the short-distance downslope movement of weathered rock
under the direct influence of gravity; also called mass movement.
Rock falling: mass wasting process in which pieces of weathered rock
fragments fall to the bottom of a cliff or steep slope.
Landsliding: an abrupt and often catastrophic event in which a large
mass of rock and/or soil slides bodily downslope in only a few seconds
or minutes. An instantaneous collapse of a slope.
Slumping: a slope collapse slide with rotation along a curving sliding
plane.
Earthflowing: mass wasting process in which a portion of a watersaturated slope moves a short distance downhill.
Mudflowing: rapid, downslope movement of a dense mixture of
weathered rock and water through or within a valley.
Saturation
Precipitation
Creeping: the slowest and least perceptible form of mass wasting,
which consist of very gradual downhill movement of soil and regolith.
Solifluction: a special form of soil creep in tundra areas, associated
with summer thawing of the near-surface portion of permafrost,
causing in the wet, heavy surface material to sag slowly downslope.
Erosion:
a natural process which is usually made by rock and soil being
loosened from the earth’s surface at one location and moved to another.
Erosion changes the landscape by wearing down mountains, filling in valleys,
and making rivers appear and disappear often by water, wind, or ice.
Erosion can be speed up by such human activities as farming and mining.
Erosion begins with a process called weathering.
Erosion moves bits of rock or soil from one place to another.
Disintegration: is fragmentation of rock and there is no chemical change
during or after this process.
Decomposition: is resulting in the destruction of some or all of the unstable
minerals and thus chemical change occur and new minerals are formed.
Transportation: the process that carry sediment or other materials away
from their point of origin. The agents of transportation are wind, water, ice
and gravity.
Alarcon 4
Deposition:occurs
due to physical (loss of energy) or chemical changes and
results in material being laid down on the Earth’s surface. One sedimentary
bed is the result of one period of deposition.
Suspension:fine, clay-sized particles are carried in the water giving water a
murky appeareance.
Burial: occurs as sediment is covered over as more layers of sediment
accumulate on top.
Sedimentation: when stuff settle down. After erosion and start piling up
Lithification: process of converting loose sediment into a sedimentary rock.
Diagenesis: all the phisycal and chemical processes that operate during
lithification.
Compaction: (physical process) grains move closer together due to weight of
overburden, porosity is reduced.
Cementation: (chemical process) a crystalline cement is precipitated in the
pore space from circulating pore fluids.
Eruption:
Saltation: a specific type of particle transport by fluids such as wind or
water. It occurs when loose material is removed from a bed and carried by
the fluid, before being transported back to the surface.
Traction: coarse boulders sliding and rolling along the bottom, they are very
heavy to be lifted by the water.
Sand transportation:
Back Washing: water moving seaward after the momentum of the wave
swash is overcome by gravity and friction.
Beach drifting: the zigzag movement of sediment caused by waves washing
particles onto a beach at a slight angle; the net result is the movement of
sediment along the coast in a general downwind direction.
Bedding plane: flat surfaces separating one sedimentary layer from the next
Bedload: sand, gravel, and larger rock fragments moving in a stream by
saltation and traction.
Down cutting: action of stream to erode a deeper channel; occurs when
stream is flowing swiftly and/or flowing down a steep slope.
Metamorphism: is the process by which rocks in the Earth’s crust are
changed by the effects of heat and pressure.
Melting: back to magma. To go from a solid state to a liquid state.
Denudation: the total effect of all actions (wxg mass wasting and erosion)
that lower the surface of the continents.
Alarcon 5
Plate tectonics
Seafloor spreading: the pulling apart of lithospheric plates to permit
the rise of deep-seated magma to earth’s surface in midocean ridges.
Rising plume
Subducting oceanic plate
Converging plate: collision.
Upwelling: cold, deep ocean water that rises to the surface where wind
patterns deflect surface water away from the coast
Spreading ridge
Upwarping
Rock openings
Jointing
What is the Rock Cycle?
Like most Earth materials, rocks are created and destroyed in cycles. The rock cycle is a model
that describes the formation, breakdown, and reformation of a rock as a result of sedimentary,
igneous, and metamorphic
processes. All rocks are
made up of minerals. A
mineral is defined as a
naturally occurring,
crystalline solid of definite
chemical composition and
a characteristic crystal
structure. A rock is any
naturally formed,
nonliving, firm, and
coherent aggregate mass
of solid matter that
constitutes part of a planet.
Igneous rocks- form in
two very different environments. All igneous rocks start out as melted rock, (magma) and then
crystallize, or freeze. Bowen's Reaction Series is a proposed sequence of mineral crystallization
from basaltic magma, based on experimental evidence. Volcanic processes form extrusive
igneous rocks. Extrusive rocks cool quickly on or very near the surface of the earth. Fast cooling
makes crystals too small to see without some kind of magnifier. Basalt is dark rock, gray or
black on a freshly broken surface, and weathers brown or red, because it contains lots of darkcolored minerals.
Alarcon 6
Some basalt contains light-colored crystals. Dacite and andesite are
medium in color, and contains medium amounts of dark minerals.
Rhyolite is the lightest colored volcanic rock. Rhyolite contains very few
dark minerals, but sometimes, rhyolite cools so fast that it quenches and
forms volcanic glass instead of crystallizing. Volcanic glass looks dark
because of the way light passes through it.
Obsidian is volcanic glass. Rhyolite is the most
common source of volcanic ash and pumice in
Idaho. Intrusive
igneous rocks cool in plutons (Pluto was the
Roman god of the
Underworld.) deep below the surface of the Earth.
Slow cooling allows
the growth of large crystals. Crystals in intrusive
rocks are visible
without magnification. Granite has the same
minerals as rhyolite,
but in much larger crystals. Diorite is the intrusive version of andesite, granodiorite is the
intrusive version of dacite, and gabbro is the intrusive version of basalt.
Metamorphic Rock- Metamorphic rocks form when sedimentary, igneous, or other
metamorphic rocks are subjected to heat and pressure from burial or contact with intrusive or
extrusive igneous rocks. ("Meta" means change, and "morph" means form.) Heat and pressure
from burial cause molecules of flat minerals like mica to line up perpendicular to the direction of
greatest compression. Deep burial means higher pressure and hotter temperatures, and very high
temperature and pressures cause the formation of new minerals, and mineral grains. Low-grade
metamorphic rocks like slate and phyllite break in flat pieces, and have a sheen on the surface.
Schist is shiny, and many schists contain garnets, staurolites or other mineral crystals that have
grown within the rock. Gneiss is a foliated metamorphic rock. Layers of dark and light minerals
stripe the rock, and sometimes it is possible to see how the direction of pressure deep in the Earth
changed as the minerals formed. The change in direction forms eye-shaped pods of minerals,
called augens ("augen" is German for "eye.") Quartzite is another important metamorphic rock in
Idaho. Quartzite is metamorphosed sandstone. Some Idaho quartzite is so pure that it can be used
to make computer chips. The most common contact metamorphic rock in Idaho is marble. The
Portneuf Gap area provides good examples of Idaho marble. Marble forms when limestone is
intruded by a pluton which heats the limestone.
Sedimentary Rock- Sedimentary rocks are those rocks made up of
pieces of other rocks. We call the pieces of rock "clasts" (Clast means
"broken piece"). A clast is a piece of rock broken off of another rock.
Clasts of rock are eroded from larger rocks, transported (moved) by wind
or water and deposited in a basin.After some period of time, the clasts are
lithified (lithos is the Greek word for stone). The sedimentary rocks we
see today were once gravel, sand, silt, mud, or living things. We decide
what to name sedimentary rocks based on the size of the clasts that make
up the rock. For most sedimentary rocks, this is easy. Sandstone is made of sand, siltstone is
made of silt, mudstone is made of mud and so on. Even volcanic ash can become sedimentary
rock! The only hard ones to remember are conglomerate and breccia. Conglomerates are made
up of rounded, gravel-size particles (To a geologist, gravel is anything from 2mm to 4 meters in
diameter), and breccia is made up of angular, sharp-edged, gravel-sized clasts. Limestone and
chert are classified as sedimentary rocks, but most limestone and chert are grown by living
Alarcon 7
organisms rather than broken from other rocks. Some limestones have fossils, but most
limestones and cherts have recrystallized, and the remains of the creatures that made them are no
longer visible.
Terms:
Cementation- The process by which clastic sediment is lithified by precipitation of mineral
cement, such as calcite cement, among the grains of the sediment.
Compaction- Tighter packing of sedimentary grains causing weak lithification and a decrease in
porosity, usually from the weight of overlying sediment.
Deposition- The settling of materials out of a transporting medium.
Erosion- The processes that loosen sediment and move it from one place to another on Earth's
surface. Agents of erosion include water, ice, wind, and gravity.
Lithification- The processes by which sediment is converted into sedimentary rock. These
processes include cementation and compaction.
Magma- Molten rock, generally a silicate melt with suspended crystals and dissolved gases.
Melting- To go from a solid state to a liquid state.
Metamorphism- Alteration of the minerals and textures of a rock by changes in temperature and
pressure, and/or by a gain or loss of chemical components.
Pressure- The force per unit of area exerted upon something, such as on a surface.
Sediment- Material (such as gravel, sand, mud, and lime) that is transported and deposited by
wind, water, ice, or gravity; material that is precipitated from solution; deposits of organic origin
(such as coal and coral reefs).
Transportation- The processes that carry sediment or other materials away from their point of
origin. Transporting media include wind, water and mantle convection currents
Uplift-A structurally high area in the crust, produced by movements that raise the rocks, as in a
broad dome or arch.Weathering- The processes by which rocks are chemically altered or
physically broken into fragments as a result of exposure to atmospheric agents and the pressures
and temperatures at or near Earth's surface, with little or no transportation of the loosened or
altered materials.