1. GEOLOGICAL TIME SCALE AND EARTH’S STRUCTURE
APES UNIT 1 NOTES
GEOLOGICAL TIME SCALE
AND
EARTH’S STRUCTURE

2. GEOLOGY The study of the nonliving parts of the Earth such as:
rocks, soil, land features
GEOLOGIST study Geology

3. 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

4. RELATIVE TIME MEASUREMENTS
Measurements that give you the age of rock and soil layers by comparing them to layers above and below
RELATIVE DATING
Dates an unknown sample to a certain time period when compared to samples of known ages
PRINCIPLE OF SUPERPOSITION
layers are piled on top of each other over time…
Strata are laid down in succession
Top layers are youngest
Bottom layers are oldest

5. ABSOLUTE DATING
Process of determining an approximate age of rocks by using radiometric methods

6. 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

7. IMPORTANT STAGES IN EARTH’S HISTORY
*4.6 BILLION YEARS AGO (HADEAN EON) = ORIGIN OF EARTH- NO LIFE
*3.5 BILLION YEARS AGO (ARCHEON EON/PRECAMBRIAN ERA) = FIRST PROKARYOTIC CELL- LIFE
*2.5 BILLION YEARS AGO(PROTEROZOIC EON/PRECAMBRIAN ERA) = ATMOSPHERIC OXYGEN EXISTS
*1.5 BILLION YEARS AGO(PROTEROZOIC EON/PRECAMBRIAN ERA) = FIRST EUKARYOTIC CELL
*550 MILLION YEARS AGO(PROTEROZOIC EON/
PALEOZOIC ERA/CAMBRIAN PERIOD) = PRIMITIVE ALGAE/MARINE INVERTEBRATES
*450 MILLION YEARS AGO (PHANEROZOIC EON/PALEOZOIC ERA/ = FIRST MARINE VERTEBRATES (FISH)
ORDOVICIAN PERIOD)
*400 MILLION YEARS AGO (PHANEROZOIC EON/
PALEOZOIC ERA/SILURIAN PERIOD) = 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
PALEOCENE EPOCH)
2 MILLION YEARS AGO(CENOZOIC ERA/QUATERNARY PERIOD) =FIRST MAN/MAMMALS/INSECTS/FLOWERS
PLEISTOCENE EPOCH)

8. Earth and our Solar System
_________ planet from the Sun
3rd
*only planet that can support _______________
life
*orbits the Sun in an ____________ pattern/shape
elliptical
*takes ________ days to complete one orbit
365
*takes _____ hours to complete one rotation 24
*was formed _______ billion years ago
4.6

9. 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

10. 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)

11. 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

12. 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
LAYERS GET DENSER TOWARDS THE MIDDLE

13. 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 ° C
PHYSICAL