GEOLOGICAL TIME SCALE Textbook pages 207-209, 212

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

JAMES HUTTON Changes in the Earth’s surface happened slowly. “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 PRINCIPLE OF SUPERPOSITION Strata are laid down in succession (layers are piled on top of each other over time) RELATIVE DATING 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

ABSOLUTE DATING Process of determining an approximate age of rocks by using radiometric methods https://www.youtube.com/watch?v=phZeE7Att_s

Two Kinds of Ages Relative - Know Order of Events But Not Dates Civil War Happened Before W.W.II Bedrock in Wisconsin Formed Before The Glaciers Came Absolute - Know Dates Civil War 1861-1865 World War II 1939-1945 Glaciers Left Wisconsin About 11,000 Years Ago

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) = 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) 1.8 MILLION YEARS AGO(CENOZOIC ERA/QUATERNARY PERIOD) =FIRST MAN/MAMMALS/INSECTS/FLOWERS PLEISTOCENE EPOCH)

Geologic Time Scale Music Video https://www.youtube.com/watch?v=7PQURsc2SYs