APES
UNIT 1 NOTES
GEOLOGICAL TIME SCALE
AND
EARTH’S STRUCTURE
GEOLOGY
The study of the nonliving parts of the Earth such as:
rocks, soil, land features
GEOLOGIST study Geology
JAMES HUTTON
“FATHER OF MODERN GEOLOGY”
Figured out sedimentary rock gets
compacted and compressed over time
PRINCIPLE OF UNIFORMITARIANISM=
changes in the Earth’s surface happened
slowly. Example: gradual shifting across
different continental land forms
https://www.youtube.com/watch?v=lMfPSdrrjZI
RELATIVE TIME MEASUREMENTS
Measurements that give you the age of rock and soil
layers by comparing them to layers above and below
RELATIVE DATING
PRINCIPLE OF
SUPERPOSITION
Dates an unknown sample
to a certain time period
when compared to samples
of a known time period
Top layers are youngest
Bottom layers are oldest
Strata are laid down in succession
(layers are piled on top of each
other over time)
ABSOLUTE DATING
Process of determining an approximate age
of rocks by using radiometric methods
https://www.youtube.com/watch?v=phZeE7Att_s
GEOLOGICAL TIME SCALE
*The history of the Earth is
measured in Geological Time
*It is organized according to major
events
*The largest unit of time is EON
EON
ERA
PERIOD
EPOCH
IMPORTANT STAGES IN EARTH’S HISTORY
*4.6 BILLION YEARS AGO (HADEAN EON)
*3.5 BILLION YEARS AGO (ARCHEON EON/PRECAMBRIAN ERA)
*2.5 BILLION YEARS AGO(PROTEROZOIC EON/PRECAMBRIAN ERA)
*1.5 BILLION YEARS AGO(PROTEROZOIC EON/PRECAMBRIAN ERA)
*550 MILLION YEARS AGO(PROTEROZOIC EON/
PALEOZOIC ERA/CAMBRIAN PERIOD)
*450 MILLION YEARS AGO (PHANEROZOIC EON/PALEOZOIC ERA/
=
=
=
=
ORIGIN OF EARTH- NO LIFE
FIRST PROKARYOTIC CELL- LIFE
ATMOSPHERIC OXYGEN EXISTS
FIRST EUKARYOTIC CELL
= PRIMITIVE ALGAE/MARINE INVERTEBRATES
= FIRST MARINE VERTEBRATES (FISH)
ORDOVICIAN PERIOD)
*400 MILLION YEARS AGO (PHANEROZOIC EON/
= FIRST LAND INVERTEBRATES & PLANTS
*200 MILLION YEARS AGO (MESOZOIC ERA/TRIASSIC PERIOD)
= FRIST BIRDS/ROCKY MOUNTAINS FORM
*150 MILLION YEARS AGO (MESOZOIC ERA/JURASSIC PERIOD)
= AGE OF DINOSAURS
*65 MILLION YEARS AGO(CENOZOIC ERA/TERTIARY PALEOGENE PERIOD)=EXTINCTION OF DINOSAURS
PALEOZOIC ERA/SILURIAN PERIOD)
PALEOCENE EPOCH)
• 2 MILLION YEARS AGO(CENOZOIC ERA/QUATERNARY PERIOD)
•
PLEISTOCENE EPOCH)
=FIRST MAN/MAMMALS/INSECTS/FLOWERS
Earth and our Solar System
3rd
• _________
planet from the Sun
life
*only planet that can support _______________
elliptical
*orbits the Sun in an ____________
pattern/shape
365
*takes ________
days to complete one orbit
24
*takes _____
hours to complete one rotation
4.6
*was formed _______
billion years ago
EARTH’S INTERACTIVE COMPONENTS
GEOSPHERE = makes up the Earth’s
interior (rock)
ATMOSPHERE = makes up the gases
surrounding Earth (air)
HYDROSPHERE= makes up the areas
of water
BIOSPHERE = makes up all the living
things within the other
parts
GEOSPHERE
EARTH IS AN INTEGRATED SYSTEM OF
4 INTERACTING COMPONENTS
HOW EARTH FORMED
-
CAME FROM COSMIC DUST IN THE SOLAR SYSTEM (BIG BANG THEORY)
ALL THE ELEMENTS FOUND ON EARTH ARE AS OLD AS EARTH
EARLY EARTH WAS A HOT, MOLTEN SPHERE
AS MOLTEN MATERIAL COOLED, THE ELEMENTS SEPARATED INTO LAYERS
BASED ON MASS (HEAVY IRON TOWARDS THE CENTER)
https://www.youtube.com/watc
h?v=BBwqendK8zc
EARTH LAYERS
BECAUSE EARTH’S ELEMENTS SETTLED INTO PLACE
BASED ON MASS…… EARTH IS DIVIDED INTO LAYERS
2 GROUPS OF LAYERS:
COMPOSITIONAL LAYERS
&
PHYSICAL LAYERS
KNOWLEDGE OF EARTH’S LAYERS
*SEISMIC WAVES ANALYSIS
*LAVA ANALYSIS
*METERITE COMPOSITION
COMPOSITIONAL LAYERS OF EARTH
CRUST = thinnest, outermost layer, solid , brittle,
coolest layer, mostly oxygen
MANTLE = medium density, has magma that
circulates, mostly iron,
magnesium, aluminum
CORE = innermost layer, greatest density, hottest,
mostly iron and nickel
PHYSICAL LAYERS OF EARTH
1. LITHOSPHERE = outer layer, includes crust
and uppermost mantle,
divided into tectonic plates
2. ASTHENOSPHERE = middle part of mantle,
flexible, rock flows slowly
3. MESOPHERE = lower part of mantle
4. OUTER CORE = outer part of core, dense liquid
nickel and iron
5. INNER CORE = inner most part of core, dense
solid nickel and iron due to
pressure, over 4000 ° C
Comparison of the Compositional and
Physical Layers
Physical Layers