Geology Exam 2

Increases surface area of rock for more effective chemical reactions. Physical processes that do not change the rock's composition

freezing water enlarges cracks

releasing pressure during uplift causes rock to expand and break into sheets. Often forms dome structures.

Crystallization of salt in pores creates hollows that expand over time.

Differential weathering creating a pattern of hollows, typically in calcite cemented sandstone

Results from chemical reactions at the mineral surface causing alterations or dissolution. Minerals in the rock are altered or dissolved.

Measure of the tendency of a mineral to remain in a given form rather than react spontaneously to become a different chemical form

Forms from a reaction between carbon dioxide and water

The breakup of minerals from rain

A type of chemical reaction that involves a transfer of electrons between two species. Any type of reaction where the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.

Breakdown of a substance by water. A water molecule may be added to the resulting mineral.

Rocky pinnacle with he appearance of stacked rounded boulders

two components: the shear or driving force (fs) pushing the block down the slope, and the normal or resisting force (fn) pushing into the slope, which produces friction

Clasts

Bioclasts

Salts and chert

Weathering of rock, shell fragments, precipitation of minerals, woody plant remains

1. Siliciclastic Rocks
2. Biochemical Rocks
3. Chemical Rocks

The process by which rocks are broken down at Earth's surface

Rock properties - Solubility, structure
Climate - Moisture and temperature
Soil cover- Presence or absence
Length of exposure - Time

plant roots occupy cracks and pry rock apart

Adhesion
Cohesion
Universal solvaent

The resistance to movement of deformation proportional to normal force.

If the slope angle becomes steeper or if the earth material is weakened, shear force exceeds normal force, compromising shear strength, and downslope movement occurs

a chemical species that donates protons or hydrogen ions and/or accepts electrons

- Water can add cohesion to unconsolidated sand, increasing shear strength and angle of repose
- Too much water can lead to liquefaction
- Planes of weakness in layered rock

H20 + CO2 ↔ H2CO3 then H2CO3 ↔ H+ + HCO3-

CaCO3 + H^+ +HCO3- ↔ Ca^2+ + 2HCO3^-

2 FeS2 + 7 O2 + 2 H20 ↔ 2 Fe^2+ + H2SO4 + 2 H^+

Fe2SiO4 + 4 H2CO3 ↔ 2 Fe^2+ + 4HCO3^- + H4SiO4

2 Fe^2+ + 4 HCO3^- + ½ O2 + 2 H20 ↔ Fe2O3 4 H2CO3

CaAl2Si2O8 + H2CO3 + ½ O2 ↔ Al2Si2O5(OH)4 + Ca^2+ + CO3^2-

Mass wasting is the downhill movement of rock and soil material due to gravity

The steepest angle at which rock and soil material is stable and will not move downslope

- creep
- earthflow
- slump

- Landslide
- Mud flow

Weathering of rock, shell fragments, precipitation of minerals, woody plant remains

Grain size, sorting, rounding

Coarse → medium → fine → very fine

Well sorted, moderately sorted, poorly sorted

Angular, sub-angular, sub-rounded, rounded

Dissolved ions, suspension, saltation, traction

Particles remain in water column until water is still

Particles bouncing or skipping

Particles sliding

a function of downward gravitational force and upward frictional force and influenced by particle size and shape

Abrasion during transport will reduce and round/smooth particles downstream from place of origin

A geographic location characterized by a particular combination of geological and environmental conditions

Regions of the Earth where long-term subsidence allows for thick accumulation of sediments

Diagenesis, recrystallization, lithification

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

Develops more stable minerals

Unconsolidated sediments are transformed into solid sedimentary rock by compaction and cementation

calcite, silica, iron oxide

River channel deposit, sea floor deposit, coral-sponge reef deposit

mostly silicate minerals, Quartz, Feldspars, Micas, Clay

Composed of calcite

Composed of dolomite

Spherical sand grains composed of calcium carbonate (CaCO3) formed on the shallow seafloor (or saline lakes) in agitated water (waves)

Determining the source of a sedimentary rock by analysis of the mineral composition, fossils (if present), and texture.

Buried compacted organic material

Features in sedimentary rocks formed by processes active in environment of deposition

Sand moved by water or wind

Thin layers diagonal to rock bedding, created by migrating sand waves, bars, and dunes.

Beforms change as flow velocity increases

Rapidly deposited mixture of coarse and fine particles, generally layered from coarse to fine upward.

Undeformed strata are deposited oldest on bottom and become progressively younger toward the top

Sediment is originally deposited in horizontal layers due to gravity

Layers are originally laterally continuous across a landscape. Disconnected layers may have at one point been connected.

A fragment of rock incorporated or included in another rock is older than the host rock.

igneous intrusions, faults, and fractures are younger than the rocks they cut

Fossil organisms appear in an order; once a fossil species disappears, it never reappears higher in the sequence.

The fundamental unit of stratigraphy. A mappable unit of rock of distinctive lithology and fossil content.

An unconformity that separates crystalline rocks, either igneous or metamorphic, from sedimentary rocks.

Folded or gilded rocks truncated by an erosional surface. Layers above will be at a different angle to layers below.

Unconformity between layers of horizontal strata.

Are based on observed stratigraphic sequences in different places around the world with rocks containing distinctive fossils representing particular intervals of the geological time when they lived.

The number of protons in the atom

The number of protons and neutrons in the atom.

Atoms of an element with different numbers of neutrons

Spontaneously decay to form other isotopes of the same or different elements.

Nucleus emits 2 protons and 2 neutrons

Emission of negatively charged beta particle as one neutron transforms into a proton

Electron capture by a proton creates one neutron

Emission of positively charged beta particle as one proton transforms in a neutron

A decay series refers to the entire chain of capture/decay steps from the initial isotope to a stable isotope.

The rate of decay for any radiogenic element is described by its decay constant.

length of time required for half of the radioactive atoms in a sample to decay

Radiometric dating is best applied to minerals that form from igneous magmas. Sedimentary rock composed of minerals from weathered igneous rock cannot be dated directly by radiometric techniques. Dating Strata: calibrated, not tautology

Living things maintain their physical form and respond to changes in their environments.

A group of organisms that are closely related to each other and usually able to breed a with each other to produce viable offspring.

Community of life and the physical environment.

Populations of different species in a given area.

same species in a given area.

Ecosystem, community, population/species, organism, organ, tissue, cell.

Tundra, Taiga, temperate rainforest, temperate deciduous forests, temperate grasslands, deserts, woodlands and shrub lands, tropical rainforests, tropical deciduous forests.

The variety of species and life in the world or a particular ecosystem.

The process of genetic change in populations over generations.

a process by which characteristics that make an organism more suited to its environment become more common in a species

An organism's basic unit of inheritance between a parent and its offspring

Alternate forms of a gene

Molecules that compose genes containing the coding for traits.

A random change to DNA that can produce an altered trait in an organism.

radiation, chemicals, copying mistakes in reproduction

Diversification by continuous genetic adaptation of species to emerging or changing environments such that new species emerge

1. Evolution = progress, 2. Individuals evolve, 3. Organisms are trying to adapt, 4. Only the fittest survive, 5. Evolution takes a long time, so human actions have no impact on other species

Species richness and species evenness

When unrelated species in isolated parts of the world resemble one another because of evolutionary adaptations to similar enviornments

Only 10% of the energy at a trophies level is available to pass on to the next level

A keystone species has a disproportionately large effect on its natural environment relative to its abundance. Hold the ecosystem in balance.

The value assigned to human benefits derived from naturally functioning ecosystems

Goods humans consume that are directly provided by ecosystems.

Natural processes of ecosystems that provide favorable conditions for humans

Fundamental natural conditions upon which many other ecosystem services depend.

Benefits to humans from the environment that may not be essential to survival but enhance quality of life.

Habitat destruction, Invasive species, Pollution, Population, Climate change, Overharvesting

Layer of weathered, unconsolidated material on top of bedrock capable of supporting plant growth.

Indicative of soil formation processes.
Black to dark brown: high in organic matter.
Red: oxidized Fe+3, Blue: reduced Fe +2
Light gray to white: calcium carbonate or intense leaching

breaking up soil for planting by turning it with a plow

High environmental al impact. Our demand for goods necessitates mining.

leads to erosion and landslides in regions with steep slopes,
Nutrients are primarily held in the O horizon in tropical rainforests, which are quickly removed from erosion when trees are removed

The affordable access to enough nutritious food to maintain dietary needs.

the development of agriculture with the cultivation of crops and domestication of animals.

2500 Calories

2700 calories

Machine power, Cultivating new land,
Irrigation,
Synthetic fertilizers and pesticides,
New varieties of cropsenetic manipulation (GMOs),
Possibly 1 billion lives saved

Advances may have peaked,
Environmental toll:
soil loss and degradation,
water and air pollution,
water availability,
toxic chemicals,
loss of agrobiodiversity,
Food insecurity persists

Allows more work to be done by fewer individuals

Uses fossil fuels,
Produces pollution,
Allows for some of the additional practices that may cause harm

Deforestation,
Wetland draining,
Species loss,
Environmental service disruption

Subsurface rock containing usable water.

Allow for increased intensity of farming but nutrients are taken out of the soil faster than natural processes can replace

A chemical intended to kill insects and other organisms that damage crops.

Higher Crop Yields,
Higher Crop Quality,
Ability of a small population of agricultural producers to provide food for the much larger non agricultural population,
Lower labor costs resulting in more affordable food

Contamination of crop products with harmful chemical residues,
Contamination of soils and groundwater,
Development of crop pest populations that are resistant to agrichemical treatment,
Health risks to those who apply agrichemicals

Faster to develop than selective breeding,
Can insert genetic material from other species that would be impossible by breeding

Health effects: no compelling evidence that food is harmful to humans,
Environment: affecting gene pool of "wild" populations,
Patented and owned by multinational corporations,
Seed saving is illegal
Farmers must buy seeds from corporations,
Have led to decrease in small family farms,
High cost of seed input = smaller profit margin

Significant waste, overfishing, bycatch, sea floor destruction, mangrove deforestation

health consequences, environmental impacts, Concentrated animal feeding operations, cattle produce methane gas, cattle eat 40% of the grain produced world wide

Support local, reduce food waste, eat less meat