geos120 exam 1

geoscience

earth science, especially geology

earth science

broader field encompassing geology, biology, chemistry, physics, astronomy, meteorology, etc.

geology

scientific study of earth (past, present, and future)

geological triad

geology=study of…

* earth materials
* processes and resulting
* sedimentary structures/landforms

limestone (CaCO3)

what is the official state rock of Tennessee?

agate

what used to be the official state rock of Tennessee and was removed b/c it was not a rock?

tums (limestone)

what geologic material is used to alleviate acid stomach?

kaopectate

what geologic material is used to alleviate diarrhea?

surface processes

floods, landslides, soil erosion, and beach erosion are examples of..

internal processes

volcanoes and earthquakes are examples of..

landforms and structures

valleys and mountains are examples of..

experimental sciences

independent of time of occurrence

historical sciences

time plays a critical role in process

mississippi floodplain

which one is marked out?

western highland rim

which one is marked out?

eastern highland rim

which one is marked out?

cumberland plateau

which one is marked out?

cumberland mountains

which one is marked out?

ridge and valley

which one is marked out?

west tn lowlands

which one is marked out?

west tn uplands

which one is marked out?

central basin

which one is marked out?

sequatchie valley

which one is marked out?

blue ridge mountains

which one is marked out?

james hutton

“father of geology,” noted that the Hadrian’s Wall was thousands of years old even though there was virtually no soil development. Thus, soil development must be a slow and long-term process.

relative time

how old events or materials are in relation to other events or materials w/o numerical dates

absolute time

precise numerical dates assigned to events and materials

principle of natural causes

processes now operating or consistent w/ natural laws responsible for natural phenomena

principle of parsimony

explanations of geologic history should be as simple and direct as evidence indicates

principle of multiple working hypotheses

sound scientific investigations develop several parallel hypotheses to test simultaneously; avoid “shoe-horning” and identify most scientific sound hypotheses

principle of uniformitarianism

geologic record interpreted on geologic processes active today being same as operating in past unless the evidence indicates otherwise

principle of original horizontality

Steno’s 3 laws: strata originally deposited horizontal

principle of superposition

Steno’s 3 laws: in normal undistributed sequence of sedimentary rock, older layer is deposited on bottom, youngest on top

principle of lateral continuity

Steno’s 3 laws: strata can be traced laterally away in all directions unless they have (1) been eroded away (2) reach edge of depositional basin and “pinch out,” or (3) change character as a facies change

facies

aspects (what does it look like?); lateral change in rock or sediment type

principle of cross-cutting relationships

geologic features that cuts across another is younger than one it cuts

principle of inclusions (components)

inclusions always older than rocks they are included in

principle of metamorphism

metamorphic rocks always older than adjacent unmetamorphosed rocks

principle of biotic succession

fossils in sedimentary rocks occur in particular stratigraphic (vertical) order: predictable once original sequence is known

principle of fossil correlation

(nicholas steno) similar fossil assemblages are similar age and strata containing them are similar ages\`

principle of unconformities

planar surfaces separating successive strata and represent significant gaps in rocks sequences (“missing time”)

form due to:

* erosion of originally deposited material
* non-deposition

disconformity

what conformity type is shown?

angular uncomformity

what conformity type is shown?

nonconformity

what conformity type is shown?

radiometric

science of dating and determining numeric time of events in earth history (13 methods)

absolute time

methods to determine numerical intervals of geologic time in units of years

isotope

same element with different # of atomic weights

half life

time it takes for 1/2 of remaining unstable radioactive parent isotope to decay to stable daughter

age of rock

what formula is (# half-lives passed) \[number of years/one half-life\]?

5730

one half-life is how many years?

direct sampling

when earth delivers to us

volcanic eruptions

“earth vomits” magma erupts

diatremes and kimberlite pipes

“earth belches” deep gas and magma (source of all diamonds)

ophiolites

slices of ocean crust pushed on land

petrology

experimental studies

6000 km

how far is it to the center of earth?

deepest mine

3\.6 km @ S. Afr. Au Mine

deepest drilled hole

12\.3 km @ Kola, Siberia

seismology

what is the most useful remote sensing?

seismic waves

earthquake produced by sudden rupture of rock or slip along a fault

primary body wave

* compression waves
* fastest traveling
* push me/pull me

secondary body wave

* shear waves
* slowest traveling
* moves only through solids
* up and down

seismology

what can tell us about earth’s interior

* liquid vs solid state - p vs s waves
* density of material - speed of wave travel
* rock type - based upon density in speed of wave
* boundary changes - changes in velocity and direction of wave
* thickness - time of travel

reflection

wave bounces off boundary beneath material of contrasting density

Refraction

wave bends at boundary

outer core

through what layer do P waves slow down?

inner core

through what layer do P waves speed up?

continental drift

“pattern” (wegener - 1915)

sea floor spreading

“mechanism” (hess - 1960s)

iron

what geological phenomena did magnetometers discover?

symmetrical

is the pattern of magnetic stripping random or symmetrical about MOR?

beneath eastern mediterranean sea

where is the oldest ocean crust? (340 mil)

mid ocean ridges

where is the youngest ocean crust?

john tuzo wilson

canadian geologist, proposed tectonic plates, interact in three ways along boundaries

divergent boundary

new ocean crust created at spreading centers and displaces old crust laterally

convergent boundary

subduction zone; 3 primary types

* andean (ocean-continent)
* island arc type (ocean-ocean)
* collision (continent-continent)

wilson cycle

opening and closing of oceans; life cycle of oceans

“ring of fire and shaking”

active tectonic boundary

whole mantle convection

mantle made of one big cell

two mantle convection cells

higher and lower part had own convection cell

complex model

shallow and deep convection cells with irregular pathways

slab pull model

denser, colder plate sinks at subduction zone, pulls rest of plate behind it

ridge push model

(mantle convection) hotter mantle material roses beneath divergent boundaries, cooler material sinks at subduction zones

combined model

moving plates, EQs, and volcanic eruptions are due to earth’s loss of internal heat

geomorphology

study of surface processes and landforms

surface water

fluvial (rivers), lacustrine (lakes), and paludal (swamps)

infiltration capacity

what determines amount of surface water?

drainage basins

land area contributing H2O to river or stream

* consist of interconnected network of streams in area

divide

imaginary line separating drainage basins

dendritic

tree-like branching tributaries

* most common drainage pattern

radial

streams diverge from center point

* typical streams on volcanoes

rectangular

streams bend at right angles

* bedrock fractures perpendicular to each other

trellis

parallel running main stream and short perpendicular tributaries

* follow folds and faults in bedrock
* ex. appalachian valley and ridge

ephemeral

stream type: only flow when raining

intermittent

stream type: flow only at certain time of year (rainy season, snow melts)

perennial

stream type: flow continuously throughout the year

headwaters

upstream origination point; v-shaped

mouth

end point of river/stream into ocean or lake; wide meanders w/ floodplain

floodplain

area on either side of stream or river where alluvium accumulates during floods