Geo FInal

cosmology

the study of the origin and evolution of the universe
the theory that describes the formation of the universe is called

cosmology

the study of the origin and evolution of the universe

the theory that describes the formation of the universe is called

The Big Bang Theory

according to this theory, the universe evolved ______ years ago from a very high density and high temperature state that keeps ____ since that time

13.6 billion, expanding

The Solar System (and Earth) formed about ____ years ago

4\.5 billion

we know the age of the earth based on the age of the oldest ___ on earth

rock

The process of formation of Earth's layers is called

differentiation

The denser layer (composed of primarily Fe and Ni) is the middle and its called ___

core

The core has a ___ inner and a ___ outer

solid, liquid

the earth's crust can be of two types ___ and ___

oceanic and continental

continental crust is ___ dense than oceanic

more

continental crust is ___ thick than oceanic

more

the presence of liquid metallic elements in the outer core of rotating Earth creates the Earth's _____ ______

magnetic Field

the magnetic field is not static, the magnetic poles switch periodically in the process called magnetic ____

reversal

the outermost rigid payer composed of the crust and upper rigid mantle

lithosphere

ocean, surface and groundwater

hyrosphere

air, composed of mainly oxygen and nitrogen

atmosphere

_____ is believed to be a father of the theory called plate tectonics

wegener

according to Wegener's theory, the _____ _____ are not static, they move around colliding with each other

lithospheric plates

evidence of continental includes

matched fit of continents; climate belts; fossil distributions; rock unit distributions

evidence of seafloor

striped pattern of magnetic field; seafloor ridges and transform faults

the lithosphere consists of

the crust and upper mantle

the earths middle layer is called the

mantle

mantle is composed of several layers; the outermost one is the rigid _____

lithosphere

the _____ is the part of the mantle, not the core. It supports the lithosphere, rather than being part of it, colliding with it, or subducting under it

asthenosphere

Mesosphere

plastic (partially molten) while the rest of the mantle is solid

there are about ____ plates, they move at the velocity of ____ cm/ye

20; 1-15

plate tectonics are driven by _____ ______ in asthenosphere

convection currents

at _____ plate boundaries, plates pull apart and _____ ____ occurs

divergent; seafloor spreading

_____ plate boundaries result in mountain building

convergent

______ boundaries plates slide past one another

transform

there were a few supercontinents in the Earth's history. The latest one was called ____ and it started to break

pangea

Pangea started to break apart around ____ million years ago

200

Lava vs. Magma

Magma is composed of molten rock and is stored in the Earth's crust. Lava is magma that reaches the surface of our planet through a volcano vent.

CaCO3 in limestone and marble; gives off CO2 (fizzes) in acid

calcite

NaCl rock salt; evaporation of dense brine

halite

CaSO4; H2O; Scratch fingernail; used in drywall

gypsum

FeS2 Fools gold, cubic crystals, main source of sulfur in acid rain

Pyrite

SiO2; framework silicate, conchoidal fracture

quartz

most common mineral in earth's crust; framework silicate, also contains potassium, calcium

feldspar

sheet silicate; perfect cleavage in one direction

mica

isolated silicate; density varies with iron and magnesium content

olivine

sheet silicate usually forming tiny crystals; key constituent of mudstone

clay

has no ordered crystal lattice

glass

minerals are ____ _____ of rocks

building blocks

there are more than _____ known mineral

4\.000

to be called a mineral, the substance should have ____ characteristics

5

characteristics of minerals

solid; inorganic; naturally occurring; defined internal structure; defined chemical formula

the majority of minerals are _____

silicates

another large class is _____

carbonates

minerals are identified based on their ____

physical properties

____ is not a good characteristic for some minerals, for example quartz

color

the color of the powder that mineral leaves behind is called ____

streak

_____ is the way that light interacts with the surface of a mineral

luster

luster can be ____ or ____

metallic or nonmetallic

____ is measured by the resistance to abrasion

hardness

the hardness of glass is ___

5\.5

____ _____ is the weight of the mineral over weight of equal water volume

specific gravity

____ ____ and crystal form is the way crystals grow

crystal habit

the way the mineral breaks is its

fracture or cleavage

rocks are ____ of minerals

assemblages

rocks are ____ (forming whole), naturally occurring solid, consisting of an ____ of minerals or less commonly ____

coherent; aggregate, glass

rocks can be ____ (composed of glass; obsidian) or ____ _____ (either crystalline made up of crystals or _____ composed of individual grains)

glassy; non-glassy; clastic

there are ___ major types of rocks

3

_____ rocks are form from clasts (or grains of pre-existing rocks and are held together by ____ or formed by mineral _____ from the solution

sedimentary; cement; precipitations

_____ rocks are formed by solidification from molten state. They are composed of ____ interlocked together

igneous; crystals

Examples of igneous rocks

granite, pumice, obsidian, basalt

____ rocks are formed in a very high heat and pressure, resulting in a ____ of pre-existing rocks

metamorphic; transformation

examples of metamorphic rocks

marble and slate

Examples of sedimentary rocks

Limestone and sandstone

a ___ ____ is a very thin slice of rock allowing to study details of the rocks texture

thin section

___ ____ is an idealized cycle of processes undergone by rocks in earth's crust

rock cycle

molten rock on earths surface

lava

molten rock beneath earths surface

magma

melting of solid rocks occurs as a response to changing ___ and ___

temperature and pressure

____ melting occurs at mid-ocean ridges and rifts

decompression

decompression melting

melting that occurs as rock ascends due to a drop in confining pressure

____ melting occurs above subducting plates

flux

flux melting

the transformation of hot solid to liquid that occurs when a volatile material injects into the solid

melt composition is controlled by partial melting ____ melts first and ____ (blocks of rocks fall into magma and melt)

felsic; assimilation

____ are chunks of wall rock incorporated into magma

zenalite

____ minerals (rich in Fe and Mg) are first to crystallize and ____ to melt

mafic; last

____ minerals (rich in Si, Al,K) crystalize last and melt ___

felsic; first

igneous rocks are categorized based on their _____ and ____

texture; chemical compassion

composition is dependent on the ____ ____ texture is dependent on the ___ ____

source material; cooling rate

____ rock cools rapidly and crystals do not have time to grow large

extrusive

____ rocks cool slowly and have large crystals

intrusive

felsic magma in an extrusive setting

rhyolite

felsic magma in an intrusive setting

granite

____ texture ; both small and large crystals

porphyritic

volcanoes are the ___ through which rising magma makes its way to the surface

conduits

Lava-flow viscosity is directly tied to lava ____

composition

Felsic has _____ viscosity

high

mafic has a _______ viscosity

low

volcanoes produce a variety of deposits including

pyroclastic

magma rises because it is ____ and because of pressure from overlying rocks

bouyant

movement rates are directly controlled by magma's _____

viscosity

the rate of cooling depends on the ____ and _____ of an intrusion

size ; composition

if magma solidifies within the rock horizontal ____ ; Vertical ____; Blob shaped ____; and Mushroom shaped ____ form

sills; dikes; plutons; lapilli

vertical fractures that are hexagonal in cress sections

columellar jointing