Geol 106 exam 1

physical geology

study of earth materials and processes on the surface and interior

historical geology

study of the origin and development of earth and its biosphere

What rock and mineral types are present, how does water work to erode, and how fast is the waterfall moving upstream

physical geology would typically ask questions such as these for Niagara Falls

when did the waterfall begin, what caused the waterfall to form, and can we predict where it will be in 1000 years

historical geology would typically ask questions such as these for Niagara Falls

Neptunists

believed that the Earth’s primordial crystalline rocks were precipitated from an ancient sea

plutonists

believed that the Earth’s primordial rocks were solidified from ancient melted rock

Abraham Werner

what ancient scientist/philosopher was related to the Neptunists?

James Hutton

what ancient scientist/ philosopher was related to the plutonists?

relative dating

finding the age relative to another object or event ( younger or older or equal age) “order of events”

absolute dating

finding the age in years “calendar dating”

Nicholas Steno

noted logical methods for ordering the sequence of geologic even for undisturbed sedimentary layers

principle of superposition, principle of lateral continuity, principle of original horizontality

What principles did Steno come up with?

principle of cross-cutting relationships, principle of inclusions

What principles did Lyell come up with?

william smith

who came up with the principle of faunal succession

uniformitarianism

the assumption that the fundamental laws of nature have not changed over the life of the universe (there has been a consistency or unconformity in the operation of natural laws)

catastrophism

the assumption that the primary cause of Earth’s geologic record is a series of one or more catastrophic events that were global in scope. Gradual processes are acknowledged, but considered of secondary importance.

gradualism

the assumption that the primary cause of Earth’s geologic record is due to gradual processes that are observed today. Catastrophic processes are acknowledged, but considered of secondary importance.

diluvialism

a form of catastrophism that attributes most of the Earth’s sedimentary layers to one catastrophic global flood.

actualism

modern uniformitarianism; an attempt to disengage from gradualism

James Ussher

who was widely known for estimating the age of the Earth using biblical chronologies in the Old Testament

salt clock

Edmund Halley proposed the idea in 1715 of a ________ using ocean salinity

T. Mellarde Reade

Who first made calculations in 1876 for the “salt clock” after Edmund Halley proposed the idea

John Jolly

Who improved calculations of the “salt clock” by using Na

100 million years; 90 million

John Jolly’s estimates of the salt clock were about __________; later revised to__ __________

Isaac Newton; 50,000 years

suggested estimate of age based on time to cool from molten mass; estimated more than ___________

Lord Kelvin; 20, 40 million

Estimated age of the earth based on cooling to be __ __to__ ______ (refined multiple times over the course of his life)

alpha decay

fission tracks are damage trails caused by ________

uranium

fission track counting measures ________ content

original uranium

in fission track counting, the sum equals __________ content

we use absolute dating and index fossils to see when an estimate age would be

how do we date sedimentary rocks and the fossils inside them?

1. How much parent isotope was there to start with?
2. Were “daughter” isotopes present at the start?
3. But what if some daughter atoms DO get included?
4. What if the system is not closed?
5. How do we date sedimentary rocks and the fossils inside them?

What are the 5 problems/ questions about radiometric dating?

index fossil

fossil species with widespread geographic distribution and narrow time of existence; presence indicative of a particular time in geologic history

johannes kepler

“The chief aim of all investigations of the external world should be to discover the rational order and harmony which has been imposed on it by God”

John ray

“father of modern biology”

Copernicus

sought a better argument that was more in line with a “supremely good and orderly Creator”

Galileo

“ I have hope that in his infinite wisdom God can direct some small ray of his grace to the purity of my mind to give me some illumination about the hidden meanings of his words.”

Charles Darwin, Alfred Wallace

co-founders of evolution by natural selection

conventional

in the ____________ Earth model, Earth history is characterized by both slow and rapid processes, operating under the constant laws of physics and chemistry

catastrophic

in the conventional model, ______ events are distributed through time and geography

4\.5 billion years

In the conventional model, radiometric dating yields ages up to ____________

raised, lowered; falling/rising sea level

in the conventional model, plate tectonics gradually ____ __and__ ___ __land for example__ ___________

fossil record

in the conventional model ________ represents changing life over vast time

Pangea

most recent supercontinent

170 million

Pangea was during the mid-jurassic time which was ________ years ago

flood model

young earth model

flood

in the ________ model, the majority off earths layers are characterized by massive catastrophic global flood

radiometric ages

what is unreliable in the flood model

fast, days

in the flood model, plate tectonics was _______ __, forming mountains and trenches in__ ________

continental crust, oceanic crust, mantle, outer core, inner core

mechanical order of layers of the earth

crust, mantle, inner core, outer core

chemical model order of layers of the earth

solid, rigid

continental crust and oceanic crust are both low in density and are _____ __and__ _______

intermediate, semi-fluid

the mantle has ____ __density and is__ ________

high; Fe, Ni

the outer core has _____ __density and liquid__ ___ __and__ _____

high; solid

the inner core has _______ __density and__ _______ Fe and Ni

0-40

width of crust in km

40-2890

width of mantle in km

2890-5150

width of outer core in km

5150-6370

width of inner core in km

felsic

minerals with a lower density, lighter in color

mafic

minerals with a higher density, tend to be darker in color

continental crust; higher

________ __contains more felsic minerals (_______ silica content)

oceanic crust; lower

__________ __contains more mafic minerals (_________ silica content)

its more dense and thinner

why does the oceanic crust sit lower (two reasons)

crust, lithosphere, asthenosphere

layers of the upper mantle starting with the crust

p waves

the fastest of the two body waves, first to arrive

6-8

p-waves are usually __ __-__ ____ km/s

s-waves

waves that typically travel half as fast as p-waves

surface waves

travel at or near the air-earth interface, the slowest and last to arrive

compressional

the p-wave motion is __________

crest

the s-wave motion is a _______

destructive

surface waves are the most ________

seismic

__________ waves are bent when they enter a material with different properties

Earth

Seismic waves may also be reflected at boundaries in the ______

moho boundary

a seismic discontinuity defining transition from crust to mantle

5-65 km

in the moho boundary, crustal thickness ranges from __________ on the continents below mountain chains

basalt, gabbro

oceanic crust is of mafic rocks such as _________ (2 examples) with a thin cover of sediment

water volume, isostatic response, tectonic action

shorelines are determined by what 3 things

temperature, glaciation

water volume varies with __________ (2 things)

mid-ocean ridges, upwelling of mafic magma, formation of a new oceanic crust

a divergence in the oceanic crust creates what 3 things

volcanism

upwelling of mafic magma is also known as

rift valleys, upwelling of mafic magma, formation of new oceanic crust

divergence in continental crust creates what 3 things

Peru-Chile trench

real life example of ocean-continental convergence

japan trench

real life example of ocean-ocean convergence

himalayas

real life example of continental-continental convergence

transform fault

a strike slip fault is also a

san andres fault

a real life example of a transform/strike slip fault

old faithful

a real life example of a hot spot

continental drift

alfred wegener discovered

physical geology

weathering, soils, mass wasting, streams, glaciers, winds

historical geology

addresses earths origin and evolution, distribution of lands and seas through time, growth/reduction of mountains, etc…

hypothesis

part of the scientific method that fits all the data and is likely to account for observations

theory

a hypothesis that survives repeated challenges and is supported by accumulating favorable evidence

unconformity

a gap in the rock record produced by erosion either can occur between two flat-lying rock sequences or between two that lie at different angles

mineral

naturally occurring, crystalline structure, solid, inorganic substance and specific chemical composition

sedimentary rocks

composed of sediment that has been consolidated by compaction and cementation, or crystallization

igneous rocks

solidify from a molten rock that is cooling down ; texture reflects rate of cooling

metamorphic rocks

rock that has been changed in texture and mineral composition from its parent rock by heat, pressure, and chemically active gases or solutions

clastic

texture of sedimentary rock that contains grains and broken fragments of minerals, rocks, and fossils

carbonates

15% of all sedimentary rocks; are formed either by precipitation from seawater or by the accumulation of the shelly skeletal parts of sea creatures on the sea floor

evaporites

precipitate from bodies of water that are subjected to intense evaporation