Time Scales Time Perspectives Chronostratigraphy Geologic Time Scale

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Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay • Radiometric Dating • Pilot Knob Lab Text: Manual, p. 3, 29, 131 -136; Boggs, Ch. 18

Time Perspectives Catastrophism http: //www. meteorcrater. com/

Time Perspectives Catastrophism http: //www. meteorcrater. com/

Time Perspectives Uniformitarianism

Time Perspectives Uniformitarianism

Time Perspectives How Much is a Billion? save $100 / day ? how may

Time Perspectives How Much is a Billion? save $100 / day ? how may years to save 1 billion $

Time Scales The Geologic Time Scale: an arrangement of the earth’s geologic record into

Time Scales The Geologic Time Scale: an arrangement of the earth’s geologic record into a standard sequence of units. • relative age order • boundaries based on fossils, lithology, polarity • absolute ages by radiometric dating

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay • Radiometric Dating • Pilot Knob Lab Text: Manual, p. 3, 29, 131 -136; Boggs, Ch. 18

Chronostratigraphy: establish time relationships among rock units Geologic Time Units • Geochronologic Units -

Chronostratigraphy: establish time relationships among rock units Geologic Time Units • Geochronologic Units - time interval • Chronostratigraphic Units - rock body representative of time interval

Chronostratigraphy Geochronologic Unit – time interval Eon Era *Period Epoch Age Chron

Chronostratigraphy Geochronologic Unit – time interval Eon Era *Period Epoch Age Chron

Chronostratigraphy Geochronologic Unit – time interval Eon – Phanerozoic Era – Mesozoic *Period –

Chronostratigraphy Geochronologic Unit – time interval Eon – Phanerozoic Era – Mesozoic *Period – Cretaceous Epoch – Late Cretaceous Age – Campanian Chron – Orbitoides tissoti

Chronostratigraphy Chronostratigraphic Unit – rock bodies representative of time interval Eonothem Erathem *System Series

Chronostratigraphy Chronostratigraphic Unit – rock bodies representative of time interval Eonothem Erathem *System Series Stage Chronozone

Chronostratigraphy Chronostratigraphic Unit – rock bodies representative of time interval Eonothem Erathem *System –

Chronostratigraphy Chronostratigraphic Unit – rock bodies representative of time interval Eonothem Erathem *System – Cretaceous System Series – Upper Cretaceous Series Stage Chronozone

Chronostratigraphy System Subdivisions Period Subdivisions Lower and Upper Early and Late

Chronostratigraphy System Subdivisions Period Subdivisions Lower and Upper Early and Late

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay • Radiometric Dating • Pilot Knob Lab Text: Manual, p. 3, 29, 131 -136; Boggs, Ch. 18

Geologic Time Scale

Geologic Time Scale

(Harland et al. , 1990)

(Harland et al. , 1990)

Maastrichtian Geologic Time Scale Even More Detail… Ages of Cretaceous Period Campanian Santonian Coniacian

Maastrichtian Geologic Time Scale Even More Detail… Ages of Cretaceous Period Campanian Santonian Coniacian Turonian Cenomanian Albian Aptian Barremain Hauterivian Valanginian Ryazanian

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley.

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley. edu/precambrian. html)

Geologic Time Scale 3. 8 4. 0 3. 5 -3. 7 3. 5 3.

Geologic Time Scale 3. 8 4. 0 3. 5 -3. 7 3. 5 3. 6 4. 4 World’s Oldest Rocks (Age in Billion Years)

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley.

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley. edu/precambrian. html) www. calm. wa. gov. au/national_parks/hamelin_pool_mnr. html

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley.

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley. edu/precambrian. html) http: //www-rohan. sdsu. edu/~rhmiller/depositionfeatures 1/

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley.

Geologic Time Scale millions of years ago Precambrian Events after (http: //www. ucmp. berkeley. edu/precambrian. html) http: //www. ucmp. berkeley. edu/vendian/pter. gif

Geologic Time Scale Amphibians Land Plants Animals with Hard Parts http: //www. inhandmuseum. com/images/Geologic_Timeline.

Geologic Time Scale Amphibians Land Plants Animals with Hard Parts http: //www. inhandmuseum. com/images/Geologic_Timeline. GIF http: //palaeo. gly. bris. ac. uk/Palaeofiles/Lagerstatten/Burgess/gallery. html

Primates Break-up of Pangea Dinosaurs Amphibians Land Plants Animals with Hard Parts http: //www.

Primates Break-up of Pangea Dinosaurs Amphibians Land Plants Animals with Hard Parts http: //www. inhandmuseum. com/images/Geologic_Timeline. GIF

Human Civilizations Ice Ages Grasses Primates Break-up of Pangea Dinosaurs Amphibians Land Plants Animals

Human Civilizations Ice Ages Grasses Primates Break-up of Pangea Dinosaurs Amphibians Land Plants Animals with Hard Parts http: //www. inhandmuseum. com/images/Geologic_Timeline. GIF

Relative Time Absolute Ages

Relative Time Absolute Ages

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay • Radiometric Dating • Pilot Knob Lab Text: Manual, p. 3, 29, 131 -136; Boggs, Ch. 18

Radioactive Decay radioactive radiogenic Parent Daughter • loss of particle from nucleus • statistical

Radioactive Decay radioactive radiogenic Parent Daughter • loss of particle from nucleus • statistical behavior of population • constant decay rate

Radioactive Decay Some Types of Radioactive Decay Beta Decay: N P and lose e-

Radioactive Decay Some Types of Radioactive Decay Beta Decay: N P and lose e- Alpha Decay: lose 2 P + 2 N AGI, 1999

Radioactive Decay 87 Rb 87 Sr

Radioactive Decay 87 Rb 87 Sr

Radioactive Decay Half Life: The time required for half of the amount of parent

Radioactive Decay Half Life: The time required for half of the amount of parent to decay to daughter “Close the Box” Time Atoms Parent Atoms Daughter “Close the Box” 6 0 1 Half Life 3 3

Radioactive Decay M&M Experiment Number of Parents 100 80 60 40 20 0 0

Radioactive Decay M&M Experiment Number of Parents 100 80 60 40 20 0 0 1 2 Number of Half Lives 3 4

Radioactive Decay

Radioactive Decay

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay • Radiometric Dating • Pilot Knob Lab Text: Manual, p. 3, 29, 131 -136; Boggs, Ch. 18

Radiometric Dating Parent-Daughter Pairs Parent Daughter Half-Life (y) Age Ranges Material 238 U 206

Radiometric Dating Parent-Daughter Pairs Parent Daughter Half-Life (y) Age Ranges Material 238 U 206 Pb 4. 5 billion < 65 million zircon 235 U 207 Pb 704 million > 60 million zircon 87 Rb 87 Sr 49 billion > 5 million micas, K-spar 40 K 40 Ar 1. 3 billion > 100, 000 micas 14 C 14 N 5, 730 < 40, 000 organics, calcite

Radiometric Dating Analytical Methods isolate parent and daughter measure amount of parent and daughter

Radiometric Dating Analytical Methods isolate parent and daughter measure amount of parent and daughter

Radiometric Dating What event are you dating? volcano 2_und_nodak_edu NPS

Radiometric Dating What event are you dating? volcano 2_und_nodak_edu NPS

Radiometric Dating Considerations • choose right mineral • assume a closed system zircon

Radiometric Dating Considerations • choose right mineral • assume a closed system zircon

Radiometric Dating 14 C-dating Concerns variable production rates of 14 C old C in

Radiometric Dating 14 C-dating Concerns variable production rates of 14 C old C in oceans selective uptake of 14 C

Radiometric Dating absolute date Calibrate the Time Scale relative age biozone absolute date relative

Radiometric Dating absolute date Calibrate the Time Scale relative age biozone absolute date relative age biozone http: //www. talkorigins. org/faqs/dating. html

Radiometric Dating Assign ages to relative time period boundaries USGS

Radiometric Dating Assign ages to relative time period boundaries USGS

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay

Time Scales • Time Perspectives • Chronostratigraphy • Geologic Time Scale • Radioactive Decay • Radiometric Dating • Pilot Knob Lab Text: Manual, p. 3, 29, 131 -136; Boggs, Ch. 18

Pilot Knob Lab • basalt • pyroclastics

Pilot Knob Lab • basalt • pyroclastics

Pilot Knob Lab

Pilot Knob Lab

Pilot Knob Lab Kavachi, Solomon Islands NOOA

Pilot Knob Lab Kavachi, Solomon Islands NOOA