Geology Exam 2

Front 1

disolved gasses

Back 1

gas content effects mobility
-violence of eruption is related to how easily gases escape from magma

1-6% by weight
-mainly H2O and CO2

Front 2

basaltic lava flows

Back 2

pahoehoe- twisted, ropey (hawaii)

aa- rough, jagged, blocky

Front 3

ash and dust

Back 3

fine, glassy fragments of pyroclastic material

Front 4

lapilli

Back 4

walnut size pyroclastic material

Front 5

pumice

Back 5

porous rock from "frothy" lava, pyroclastic material

Front 6

cinders

Back 6

pea-sized pyroclastic material

Front 7

blocks and bombs

Back 7

larger than lapilli, pyroclastic material

Front 8

crater

Back 8

summit depression less than 1 km in diameter

Front 9

caldera

Back 9

summit depression greater than 1 km in diameter
-produced by collapsing after eruption

Front 10

vent

Back 10

surface opening connected to the magma chamber

Front 11

fumarole

Back 11

emit only gases and smoke

Front 12

shield volcano

Back 12

-broad, slightly dome shaped
-generally covers large areas
-produced by mild eruptions
(mauna loa on hawaii)

Front 13

cinder cone

Back 13

-built from ejected lava fragments
-steep slope angle
-small size
-frequently occurs in groups

Front 14

composite cone (stratovolcano)

Back 14

-located adjacent to Pacific Ocean
-large, classic shaped
-composed of interbedded lava flows and pyroclastic debris
-most violent type of activity

(vesuvius, st. helens)

Front 15

nuee ardente

Back 15

deadly pyroclastic flow
-hot gasses and ash
-glowing avalanche
-200 km per hour

Front 16

lahar

Back 16

volcanic mudflow
-mixture of debris and water
-moves down stream valleys and slopes, destructive results

Front 17

pyroclastic flow

Back 17

-felsic and intermediate magmas
-ash, pumice, other debris
-ejected at high velocity

(yellowstone plateau)

Front 18

fissure eruptions and lava plateaus

Back 18

fluid basaltic lava extruded from crustal fractures called fissures
(columbia river plateau)

Front 19

lava domes

Back 19

-bulbous mass of congealed lava
-associated with explosive eruptions of gas-rich magma

Front 20

volcanic pipes

Back 20

short conduits that connect magma chambers to the surface

Front 21

volcanic necks

Back 21

resistant vents left standing after erosion has removed the volcanic cone

(ship rock, new mexico)

Front 22

dikes and batholiths

Back 22

cut through preexisting rocks

Front 23

latholiths and sills

Back 23

parallel beding

Front 24

pluton

Back 24

cooled, solidified magman at depth of Earth
-tabular(sheetlike) shape vs. massive
-concordant vs. discordant

Front 25

dike

Back 25

tabular, discordant pluton

Front 26

sill

Back 26

tabular, concordant pluton
(palisades sill in NY)
-intrusive igneous feature

Front 27

laccolith

Back 27

similar to sills
-lens or mushroom shape
-arches overlying strata upward
-intrusive igneous feature

Front 28

batholith

Back 28

-largest intrusive body
-surface exposure > 100 + km2
-core of mountains
-intrusive igneous feature
-lots in the west coast

Front 29

subduction zones

Back 29

-occur in conjunction with deep oceanic trenches
-partially melting of plate and upper mantle
-can form island or volcano
-Ring of Fire

Front 30

inter plate volcanism

Back 30

-occurs within a tectonic plate
-associated with mantle plumes
-localized volcanic regions in the overriding plate are hotspots

Front 31

weathering

Back 31

physical breakdown and chemical alteration of rock at Earths surface

Front 32

decomposition

Back 32

chemical breakdown of weathering

Front 33

disintegration

Back 33

physical breakdown of weathering

Front 34

mass wasting

Back 34

the transfer of rock and soil downslope under the influence of gravity

Front 35

erosion

Back 35

the physical removal of material by mobile agents such as water, wind, ice, or gravity

Front 36

mechanical weathering

Back 36

breaking of rocks into smaller pieces
-frost wedging
-unloading
-thermal expansion
-biological activity

Front 37

chemical weathering

Back 37

breaking down of rocks components and internal structure of minerals
-most important agent is water
(responsible for transport of ions and molecules)

Front 38

dissolution

Back 38

chemical weathering aided by small amounts of acid in the water

Front 39

oxidation

Back 39

chemical weathering when any reaction where electrons are lost from one element

Front 40

hydrolysis

Back 40

chemical weathering where the reaction of any substance with water and hydrogen ions attack and replace other ions

Front 41

soil

Back 41

combination of mineral and organic matter, water and air

Front 42

regolith

Back 42

rock and mineral fragments produced by weathering that supports plant growth

Front 43

factors controlling soil formation

Back 43

-parent material
-time
-climate (precipitation and temp)
-plants and animals
-topography

Front 44

E horizon

Back 44

little organic matter
-eluviation and leaching

Front 45

B horizon

Back 45

zone of accumlation

Front 46

C horizon

Back 46

partially altered parent material

Front 47

O horizon

Back 47

organic matter

Front 48

A horizon

Back 48

organic and mineral matter
-high biological activity

Front 49

soil taxonomy

Back 49

-emphasis is placed on physical and chemical properties
-six hierarchal categories exist
-latin and greek names
-12 basic soil orders are recognized

Front 50

soil erosion

Back 50

part of natural recycling

Front 51

sedimentary rocks

Back 51

products of mechanical and chemical weathering
5% of Earth by volume
-often contain fossils

Front 52

digenesis

Back 52

chemical, physical and biological changes that take place after sediments are deposited

occurs in earths crust

Front 53

recrystalization

Back 53

development of more stable minerals from less stable ones

Front 54

lithification

Back 54

sediments are transformed into solid rock by compaction and cementation

Front 55

natural cements

Back 55

calcite, silica, iron oxide

Front 56

detrial rocks

Back 56

transported sediment as solid particles, particle size used to distinguish among various types of rocks
-clay minerals
-quartz
-feldspars
-micas

Front 57

chemical rocks

Back 57

sediment that was once in solution

Front 58

shale

Back 58

mid-sized particles in thin layers that are commonly referred to as laminea
-most common sedimentary rock

Front 59

sandstone

Back 59

-composed of sand-sized particles
-forms in variety of environments
-quartz is predominant mineral

Front 60

conglomerate and breccia

Back 60

-both are composed of particles greater than 2mm in diameter
-large round gravels for conglomerate
-breccia is mainly large angular parts

Front 61

limestone

Back 61

most abundant chemical sedimentary rock
-coral reefs, coquina, chalk
-travertine and oolitic limestones

Front 62

dolostone

Back 62

chemical sedimentary rock, formed secondarily from limestone

Front 63

chert

Back 63

microcrystalline quartz, flint, jasper, agate

Front 64

evaporties

Back 64

evaporation triggers deposition of chemical precipitate, rock salt and gypsum

Front 65

coal

Back 65

chemical sedimentary rock, organic material
1.plant material
2. peat
3. lignite
4. bituminous

Front 66

clastic

Back 66

discrete fragments and particles
-detrial are ALL clastic

Front 67

nonclastic

Back 67

-pattern of interlocking crystals
-may resemble an igneous rock

Front 68

continental environment

Back 68

-dominated by stream erosion and deposition
-glacia
-wind

Front 69

marine environment

Back 69

shallow, about 200 meters
-deep (seaward of continental shelves)

Front 70

transitional environment

Back 70

shoreline, tidal flats, lagoons, deltas

Front 71

sedimentary facies

Back 71

-different sediments often accumulate adjacent to one another at the same time
-distinctive characteristics
-merging of adjacent facies is gradual

Front 72

types of sedimentary structures

Back 72

-strata, beds (most)
-bedding planes that separate strata
-cross-bedding
-graded beds
-ripple marks
-mud cracks
-fossils

Front 73

renewable resources

Back 73

can be replenished over relatively short time spans
-plants, animals for food, trees for lumber

Front 74

nonrenewable resources

Back 74

significant deposits take millions of years to form
-fuels, coal, oil, gas
-metals, iron, copper, uranium, gold

Front 75

types of gas traps

Back 75

-anticlinal
-fault
-stratigraphic

Front 76

urban air pollution

Back 76

air pollutants are airborne particles and gases that occur in concentrations that endanger the health of organisms and disrupt the orderly functioning environment

Front 77

primary pollutants

Back 77

emitted directly from identifiable sources

Front 78

secondary pollutants

Back 78

formed when chemical reactions take place among primary pollutants

Front 79

greenhouse effect

Back 79

atmosphere is transparent to incoming short wavelength solar radiation. The ongoing long-wave radiation emitted by Earth is absorbed in the lower atmosphere, keeping air near the ground warmer

Front 80

tar sands

Back 80

mixtures of clay and sand combined with water and bitumen (viscous tar)
-several substantial deposits around the world
-obtaining oil from tar has drawbacks

Front 81

oil shale

Back 81

contains enormous amounts of untapped oil
-not worth mining because of markets and technology

Front 82

alternatives to energy sources

Back 82

-nuclear
-solar
-wind

Front 83

magmatic segregation

Back 83

separation of heavy minerals that crystalize early or rare elements melt

Front 84

diamonds

Back 84

originate at great depths
-crystals are disseminated in ultramafic rock called kimberlite

Front 85

hydrothermal solutions

Back 85

-best known and important ore deposits
-majority from hot, metal rich fluids
--move along fractures, cools and
-precipitates the metallic ions to produce vein deposits

Front 86

produced by contact metamorphism

Back 86

-sphalerite (zinc)
-galena (lead)
-chalcopyrite (copper)

Front 87

produced by regional metamorphism

Back 87

-talc
-graphite

Front 88

secondary enrichment

Back 88

concertrating metals into economically valuable concentrations

Front 89

bauxite

Back 89

-principal ore of aluminum
-forms in rainy tropical climates from chemical weathering and the removal of undesirable elements by leaching

Front 90

placers

Back 90

-deposits formed when heavy metals are mechanically concentrated by currents
-involved heavy and durable minerals
(gold, platinum, diamonds)