represents an

early stage of star formation; it consisted of a central "bulge" surrounded by a rotating flattened disk,

which itself sustains complex internal motions of dust and gas.

Inner planets

Mercury, Venus, Earth, and Mars—are relatively small, dense bodies with small

volatile substances

volatile substances

liquids, gases at room temperature

outer planets

Jupiter, Saturn, Uranus, and Neptune

“gas giants,” are of

low density; they consist mostly of volatile substances and are relatively large bodies

core

metallic;

≈16% of its volume

mantle

(

83%) consisting of

(<1%) consists of a great variety of rock types, and it

conceals the mantle almost everywhere.

O and Si most abundant- silicate minerals

feldspar most important minerals

differentiation

process of separation, or

segregation based upon differing densities

Sources of heat,

such as radioactive decay, caused early melting of material with the lower melting point, which was the

metal. Dense liquid metal filtered downward to form the core, while less dense rocky material floated

upward to make the earth's mantle, and perhaps the beginning of a crust

water could have been: (i) extracted from within the earth's interior (internal source)
(ii) deposited by impact of comets (external source).

Evidence points chiefly to volcanic activity, which is process (i).

naturally occurring, crystalline solid with a well-defined composition, inorganic

-distinctive in that the angles between particular crystal faces of a particular mineral always make the same angles with each other, even if the sizes of the faces vary from case to case.
fundamental ordering in the atomic structure of a mineral.
-Another clue is offered by X-ray diffraction, in which a thin beam of X-rays is directed at a crystal, resulting in a pattern of dots created on a film detector when the X-rays bounce off of internal planes of atoms. Whether such a reflection happens depends on the wavelength of the X-ray, the angle at which it hits the plane, and the

spacing between parallel planes. Using these dot patterns, the arrangement of the atoms in a mineral can be derived.

A crystal is built up by repeating the same atomic pattern over and over, in all directions.

“lend and borrow”

electrons to stabilize their electron configurations

more prevalent in minerals

atoms share electrons for the same purpose.

Ionic bonding is more prevalent in minerals, covalent in gases and organic molecules

Fe2+, Mg2+ - ferromagnesium

high melting point

principle mineral of upper mantle

ferromagnesian

silica tetrahedra being formed into long chains - each tetra connected to two others via O (offsets neg charge)

planes with few atomic bonds and cross no bonds and cross no bonds bw silica tetra (strong) - defines cleavage planes, natural places of weakness

meet at right angles

double chain config, pairs of chains running side by side linked by shared O

ferromagnesian

garbage cans of mineral world

structures are double wide the planes sooo 60deg-120deg

hydrous minerlas - when amphiboles break down, water can be produced

chains linked side by side ad infinitum

the cations that balance the ionic charge sandwiched bw sheets - weak but strong cleavage

MICAS

clay hazard - take water between layers swell up and shrink

carbonates (CO3-) - limestone

oxides(oxygen plus metal) - source of metals

halides (cl- and f-)- salts

sulfides (s2- plus metal) - ore min

sulfates (SO42-) - plaster wallboard sulfur loses not gains electrons

formed when moletn rock or magma solidifies

to create ig rocks solid must melt

SOLIDUS - dividing line between regions solid or partially molten

raise temp

lower pressure

change position of the solidus by adding water, which makes melting easier

defined by size shape and arrangement of mineral grains

no crystals - extremely fast cooling

small crystals - fast cooling

large - slow since more time to grow

rich in Mg and Fe - pyroxene, calcium plagio, olivine

coarse intrusive = gabbro

fine grained extrusive =basalt

more silica rich

sodium and K feld and quartz

fine grained ex - rhyolite

coarse grained ex - granite

will often be the first mineral to form, and as it grows it uses up a disproportionate amount of Fe and

Mg. Large olivine crystals may then sink to the bottom to the magma chamber because of their higher

density, leaving the melt composition permanently changed until the next mineral starts to crystallize

magmas more felsic as approaches surface

mafic magmas with low viscosity, little trapped water

lava flows extend for miles

mafic magma errupts under water - basalt pillow

felsic magma - higher viscosity - better at trapping water

underneath hot liquid but when reaches surface explosively decompresses into steam

Mt. St HELENS1q!1111

rhyolitic caldera

super explosive

large mass of rock falls into the magma

chamber, creating a depression on the Earth surface but with a piston-like action forcing out far greater

amounts of molten material than a volcano

dike

fracture that was once a conduit for granitic or basaltic

magma, now filled with solid igneous rock,

sill

magma squeezes out laterally, for

example between adjacent strata, it crystallizes as sill

batholiths

Erosion has exposed gigantic masses of granite or granodiorite, kilometers across

Llano Uplift west of Austin.

the larger the batholithic mass of magma, the

slower the rate of cooling.

Mechanical weathering is simply a reduction of

size—larger particles becoming smaller particles.

ex:

Water penetrates faults

and joints where it freezes, expanding into ice and prying rocks apart

prevails in polar regions where the rate of chemical weathering is negligible

fault

fracture along which there has been significant movement between rock masses on the opposite sides

joint

opened-up fracture that has experienced no significant movement

accomplished as water penetrates the rock, attacking mineral structures.

exfoliation

process of expansion associated with release of pressure, as overlying rock is removed by erosion, causes

curved sheets to pop off of massive, homogeneous granite

terrigenous clastic

derived from land - from weathering and erosion of source rock transported and deposited

classified according to particle sixe

CONGLOMERATE

SANDSTONE

SILTSTONE

SHALE

direct precipitation of dissolved ions

CARBONATE

CALCITE

LIMESTONE

DOLOMITE

evaporite chem sediments - chemical sediments were precipitated as the concentration of dissolved ions in seawater became highly concentrated through intense evaporation and loss of water vapor

GYPSUM, HALITE, ROCK SALT

Metamorphic rocks

to transform - solid state process

1. elevated temperature

2.elevated pressure

3. shear stress

4.water

dynamic meta - intense shearing

contact meta - high temp

regional meta - 1-4

metamorphic foliation

Alignment of needle-like or sheet-like crystals in

metamorphic rocks is a very common feature

element specifies both the number of

nuclear protons and associated neutrons

is the property of certain

isotopes by which they are unstable as such, and spontaneously transform into other isotopes.

(i) is an energy-releasing phenomenon, and
(ii) in most types of radioactive decay, a particle with mass is lost from the nucleus. Thus, in the general case a parent and its daughter are different isotopes of different elements, and hence they can be distinguished from one another.

(iii) a statistical process (one may not predict exactly when any particular parent nucleus will decay), and
(iv) there is no environmental situation commonly encountered in the earth (e. g., local pressure, temperature, type of chemical bond connecting the radioactive atom with other atoms in a crystal) that can alter the rate of decay

the length of time required for 1/2 of a beginning number of parent atoms to decay

uncomformity

buried surface of erosion, representing the passage of time during which part of

the geologic record was being destroyed through recycling (erosion). It is common to find sedimentary

strata lying above an unconformity,

It is common to find sedimentary

strata lying above an unconformity, beneath which lie vastly more ancient (i.e., Precambrian), once

deep-seated igneous and metamorphic rocks

Precambrian shields

i.) areas of vast size (perhaps occupying half or more of a continent)

(ii) very stable, having long been subjected to deep erosion which has transformed them into
(iii) terrains of low elevation above sea level, and low topographic relief (local differences of elevation between high and low spots), that are
(iv) composed chiefly of Precambrian igneous and metamorphic basement rocks, and
(v) commonly containing large ore deposits

of economically important minerals (basis of the mining industry).
(vi) Every continent contains at least one Precambrian shield, the North American representative being the Canadian Shield that comprises the eastern two-thirds of Canada

("pre-nucleated"), lacking a defined nucleus or

other intra-cellular structures surrounded by membranes

All other organisms, whether single-celled or

multi-celled

("truly nuclear") whose cells do contain such internal structures. Examples of internal cell structures are the nucleus, mitochondria that engage in energy transfer, and (in photosynthetic organisms) plastids that contain chlorophyll. Eukaryotes appeared in the fossil record very much later than prokaryotes.

a distinctive fossil consisting of fine laminations, signifies the former presence of algae.

prominent fossil type in Precambrian rocks.

permineralization

More common body fossils are hard parts like bone, teeth, or shell in which the natural pores are filled with minerals by percolating water.

replacement,

hard material is replaced atom-by-atom by minerals in fluids

compression

If a carbon-rich film remains when you preserve soft material is by flattening it between layers of sediment.

impression

imprint of its form

version of replacement the organism entirely dissolves away while the surrounding matrix remains intact

void in the rock in the shape of the organism (or more likely its shell).

Later fluids can fill the void with another mineral

A special type of cast, in which the shell of a gastropod is lost but the sediment filling in the shell is preserved

Natural biases

include anatomy, depositional environment, and geological history.

stem from geography (how accessible is a fossil locality, and how many paleontologists are nearby); and observer/collector competence, motivation, and research interest.

("advanced animals") are the soft-bodied Ediacaran fauna, which are found in strata from the late Precambrian.

Lacking any hard parts, they were probably mostly passive feeders.

prokaryotes - archea and bacteria

eukaryotes - animalia, plantae, fungi, and protoctista

science of interpreting the spatial and temporal relationships among layers of sedimentary rock, or strata

states that, in a typical sedimentary sequence, the oldest rocks are on the bottom and the youngest on top; in other words, the younger layers must have been deposited on top of older ones.

reflects that rock layers are usually laid down in flat layers that are close to horizontal due to the influence of gravity.

which points out that stratigraphic layers are continuous until truncated, whether by pinch-out, abutment against older rocks (i.e. the edge of a basin), erosion, or faulting.

which states that rocks that are cut by another geologic feature are older than the feature that cuts them.

law establishes the relative timing between strata and other geological events like intrusion by magmas forming igneous rocks, disruption by faulting, tilting and folding, and erosion.

applies if there are clasts (fragments) of one rock type included in another, in which case it can be concluded that the fragmented rock is the older one.

based on the observation that there has been a systematic progression of life through time. Organisms appear in the rock record and then disappear, never to arise again

determining how to match strata up when separated by distance or poor exposure.

most useful fossils for correlation
 

these are characterized by being abundant and widespread, and thus relatively easy to find, but only appearing over a confined interval of geologic time.

sets of different species that only overlap during a confined time interval) can also be used for the same purpose

loosely defined as a distinct rock unit that is large enough to appear on a map. Formations are subdivided into

, to provide detail or generality as necessary to usefully characterize the rocks in a region.

(such as the Cambrian or Triassic

collection of organisms with a single common ancestor

"mouth second," and refers to the order in which the holes that eventually become the mouth and anus form in the embryo

dorsal nerve cord to carry signals across the body and a notochord to protect it and give it some rigidity and serving as a site for muscle attachment.

In primitive chordates the notochord is present throughout life, but in vertebrates it occurs only in the embryo.

Other chordate characters include pharyngeal slits and a circulatory system. In fish the pharyngeal slits eventually lead to the development of gills, but in later vertebrates like mammals they are, as with the notochord, only present in the embryo.

bony skeleton

nervous system- brain, sensory structures

ordovician

bony external armor - grovel through mud for food

sucking parasites lampreys and hagfish

first jawed fish

silurian

grew great in size

dead end

sharks, rays

devonian

rarely preserved

devonian

enamel sclaes

internal body skeleton

99,9% ray finned - pectoral fins supported by thin bony rays that ecxtend for the most or all of the lenth of the fin

lobe finned - thicker sturdier bones that protrude only slightly into the fin - less effective swimmer - lunghsih?

self-contained watery environment in which the embryo could grow while protected by a tough but also porous shell that allowed gas exchange for respiration

gas exchange requirement of the egg limits the size that it can be

referring to two holes in the skull behind the orbit (eye hole) acquired as a trait early in their history. The most notorious of these, the

, are divided into lizard-hipped and bird-hipped varieties. Other Mesozoic reptiles of note are the flying pterosaurs and swimming mosasaurs, plesiosaurs and ichthyosaurs, all descendants of creatures that lived exclusively on land.

most primitive bird known,

, has a combination of features from dinosaurs (teeth, finger claws, bony tail) and birds (wishbone, wings, feathers), making it a transitional form.

appeared, being distinguished by having only a single primitive skull hole where the diapsids had two.

 Synapsids featured serrated differentiated teeth, and are thought to have been endothermic (warm-blooded).

monotremes

, which lay eggs,

the marsupials, which give birth while their young are in a very immature state and subsequently carry them in pouches, and

placentals, which bear live and well-developed young

A comparison of placentals and marsupials illustrated

in which organisms with different ancestries can come to have very similar forms when they fill similar ecological niches. Placentals outcompeted marsupials in most of the world and came to be the dominant mammals, but in Australia the marsupials won out, and for tens of millions of years there were no placentals in Australia due to its isolation.

is the direction of maximum slope (where a ball would roll down if placed on the plane

perpendicular to the dip, and is the direction of zero slope; i.e. horizontal

one in which gravity is the principal influence in transporting sediments to lower elevations

rivers

which sediment transport is along a horizontal plane, such as sea level

plot of river elevation versus distance from the coast.

smaller streams that progressively combine into larger ones, until they join a master river

Once this river nears the coast, in many cases it splits into a

with multiple channels leading to the sea.

consists of ions that are soluble in water (i.e. salts such Na, K, Ca, Cl).

the size of particle that can be suspended depends on river

turbulence

Sand and larger sediments pushed along the bottom of a channel

along banks

when the river overflows its banks the great reduction in velocity causes the suspended load to be quickly dropped

When rivers flow through alluvial plains (consisting mostly of unlithified sediment) they often develop curves

As the bend migrates, coarser sand and gravel are left behind on the inner part of the loop

built when a river reaches the sea, water energy decreases and it starts depositing its load

form of a delta is largely determined by the rate at which sediment is delivered (the Mississippi river delivers about a metric ton a day) versus how fast it is taken away by along-shore processes.

If sediment input is faster

building itself and extending the shoreline outward

sequence of growth, abandonment, subsidence, and renewed deposition

dominated by wave action

wind blows over water, friction sends water molecules downward, after which they ride again traqcing circular paths

When waves hit a beach, typically at some angle, they propel sediment uphill in the direction of the wave, after which gravity drags the water and sediment back toward the shoreline

This action causes the sediment to be pushed along a beach

weak

low density

non porous

excellent trap - oil

when subject to great pressure from overlying sediments due to burial it will eventually flow and rise in various structures including domes and diapirs - mushroom cloud

As the ice melted and sea level rose again, the incised channels were flooded and became bays, and the sand was driven back toward the shore by wave action, creating

, such as South Padre Island.

depnds on

(i)

, which is a measure of the resistance of the material to being compressed,

(ii)

, which is a measure of the resistance of the material to being deformed by shear stress, and

(iii)

of the material.

which time is the interval between an earthquake and arrival of a seismic wave at a seismometer station at a given distance. At greater distances, arrivals are later and later, and from the slope of the line thus generated, we may calculate the seismic wave spee

spot at the surface directly above the focus

plotted on maps

surface

is an instrument that record seismic wave motion

principle of a steady mass that is suspended in mechanical motion

primary

compressional

push-pull

travel fastest

an individual atom vibrates back and forth in direction PARALLEL to direction of wave travel

travel through solids, liquids, gases

body waves - travel through deep body of earth

secondary

shear

shake

shimmy

slower

individual atoms travel back and forth in a direction that is PERPENDICULAR to direction of wave travel

travels only through solids

body waves

only travel through outer part of earth (L)

long wavelengths

individual atoms manifest complex motion

expanding concentric circles

instntaneous positions of corresponding parts of the waves

ex; all wave troughs or crest

temporary - atoms vibrate and reutrn to where they started

change of size, shape, or both

earth manifested as fault offset

flotational equilibrium amongst large segments of the earth’s crust

high mountains are underlain by least dense crust, low plains by more dense crust, and the densest crust underlies the ocean floor. All segments of denser or less dense crust are "floating" upon even more dense material at depth

plate initially of uniform thickness expands upward to various extents, and in doing so, acquiring different densities.

high topography is underlain by thick crust, and low topography is underlain by thin crust of the same density

accomplished through crust of varying thickness, the base of the crust being a mirror image of its topographic surface.

comprised of low-density granitic material stands higher than oceanic crust

oceanic crust comprised of high-density basalt

organized motion of electrically charge particals

POLARITY - both attraction and repulsion

unpaired electrons whose directions of spin are aligned, and in this sense there is an organized motion of electrical charge

organized motion is an electric current, a flow of electrons through a conductor. The field associated with an electromagnet disappears when the current is shut off.

Curie temperature

580°C for magnetite

Temperature increases with depth in the earth such that all rocks deeper than the base of the crust are hotter than the Curie temperature for any magnetic mineral

a volume of space where magnetic force is present) is conveniently described by

magnetic lines of force.

ascending and descending

to date many basalt flows

quite accurately

excellent fit

ancient rocks show eiddence that local climate differed from today

distribution of fossils

distribution of ancient mountain belts and zones of regional metamorphism

apparent polar wandering waves

plates that are in motion (horizontal)

thermally driven

convection motion in mantle - where mantle is cool it contracts becoming denser and then it sinks

high T high P in balance

mantle is softened, lil melted

S waves almost don't make it through this zone

when melted becomes basaltic magma upon ascent to the earths surface

ACTS AS A DUCTILE LUBRICATING LAYER OVER WHICH THE STRONG, RIGID, BRITTLE PLATES ARE IN MOTION

"rock sphere"

strength and rigidity

comprised of either continental or oceanic crust and uppermost mantle acting coherently as a unit

interaction among plates

1. pulling apart from one another

2. colliding

3. slipping sideways past one another

mid-ocean ridge system, where oceanic crust is created

on continents correspond to RIFT VALLEYS

equal with either the ocean trench system where OCEANIC CRUST IS BEING CONSUMED

on continents - COMPRESSIONAL MOUNTAIN RANGES (HIMALAYAS)

fracture zones (most are submarine)

but as cuts through continent - San andreas fault system

fell short of its potential to develop into a new ocean basin

like east african rift valleys

a place where the earth's magnetic field strength is higher than the regional average

The magnetic field generated by magnetic minerals (for example, magnetite) in this basalt is added to the magnetic field currently being generated in the earth's core. then reults innnnnnnnn

 Adjacent to this ocean-floor stripe is another magnetic stripe that crystallized in a reverse magnetic field, in which the South and North magnetic poles occupied positions that are the opposite of what we see today.

Magnetism in magnetic minerals in this stripe is oriented in the opposite direction;

it partially cancels the magnetism coming from the earth's core

where the field is weaker than the regional average

experiences strike - slip motion

at their two ends they transform into some other type of plate tectonic boundary

accumulation of wastage blance

end of glacier

versions of the same element with different numbers of protons, and do not undergo radioactive decay

heavier ^{18O is more likely to transform from vapor to liquid or solid}

lighter ^{16O atom moves somewhat more quickly at a given energy, and thus is more likely to transform from a solid or liquid into a vapor}