Carbon isotope study on fossils

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2. CONTENTS
 INTRODUCTION
 DATING METHODS
 HOW IS RADIO ACTIVE DATING
PERFORMED?
 FORMULA FOR DATING FOSSIL
SAMPLES BY C-14 DATING
 LIMITATION
 CONCLUSION
 REFERENCE
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3. INTRODUCTION
Fossils are the remains or evidences of
life from a previous geological time. The study of
fossils is called paleontology. there are mainly 7
branches in paleontology, they are Paleobotony,
Palynology, Stromatology, Paleozoology,
Invertebrate paleontology, Vertebrate
paleontology, Micro paleontology. The study of
fossils plays a wide role in origin, evolution and
extinction of fossils (LIFE), Age determination of
rocks by absolute (Radio active) and relative
methods (Fossils), Oil & Coal exploration,
Engineering projects and also in Crime detection
etc.,
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4. DATING METHODS
There are 2 types of dating methods
1.Absolute method or Radio active method
2.Relative method by correlation with fossils
1.Absolute method:
Absolute dating uses radioactive decay rates to establish a date for the
site and its artifacts. Radioactive materials decay at known rates. By
calculation, the age of what is tested can be determined. The radioactive
method’s half-life is too short to determine geological era dates.
2. Relative Dating
Relative dating is to establish a chronology of the site and arrives
at a date relative to the objects found around it. Comparing pottery styles to
known dated samples, or items found in the same sedimentary layer, would be
examples of relative dating.
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5. HOW IS RADIO ACTIVE DATING
PERFORMED?
Many rocks and parts of organisms like
bones, skeletons, shells contains minerals like
radio active isotopes, such as U-235 and C-14.
these are unstable and decaying over time at
a predictable rate. As they decay they give off
particles from their nucleus and became a
different isotope.
Parent isotope is original unstable
isotope. Daughter / product isotope are
stable products of decay
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6. Contd…
Half life:
It is the amount of time it takes for half
of the parent isotopes to decay. It occurs on
logarithmic scale.
ex: half life of C-14 is 5730 years it means in
1st 5730 years organism(bones, skeleton,
shells) looses its half of its c-14 isotope. In
another 5730 years it will loose another half of
remaining c-14 isotope.
PARENT PRODUCT
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HALF LIFE PERIOD

7. Contd..
 The fossils are collected along with rocks that
occurs from the same strata.
 These are analyzed by using mass
spectrometer.
 This gives information about the type and
amount of isotope found in rocks / fossils .
 Scientists find the ratio of parent isotope to
daughter isotope by comparing this ratio to
the half life logarithmic scale of the parent
isotope.
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9. LIST OF RADIOACTIVE ISOTOPES WITH
THEIR HALF LIFE
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Isotope
half-life
10−24
seconds
Hydrogen-7 23
Lithium-4 75.7
Hydrogen-5 80
Hydrogen-4 100
Hydrogen-6 290
Lithium-5 300
Boron-7 350
Helium-5 760
half-life
10−21
seconds
Helium-10 1.52
Lithium-10 2
Carbon-8 2
Helium-7 3.04
Beryllium-6 5
Helium-9 7
Boron-9 800

10. Isotope
half-life
10−12
seconds
Boron-16 190
Beryllium-13 500
Isotope
half-life
10−9
seconds
Lithium-12 10
Boron-18 26
Carbon-21 30
Beryllium-15 200
Beryllium-16 200
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…
Contd…

11. Contd…
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isotope
half-life
10−3
seconds
Boron-17 5.08
Boron-15 9.87
Boron-14 12.5
Boron-13 17.33
Boron-12 20.2
Carbon-19 46.2
Carbon-18 92
Carbon-9 126.5
Carbon-17 193
Boron-8 770
10

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isotope
half-life
1018
years 1024
seconds
Vanadium-50 0.14 ± 0.04 4.4 ± 1.3
Tungsten-180 1.8 ± .2 57 ± 6.3
Europium-151 5 160
Molybdenum-100 8.5 270
Cadmium-116 31 ± 4 980 ± 130
1021
years 1027
seconds
Selenium-82 0.097 3.1
Tellurium-130 0.79 25
Germanium-76 1.8 0.057
Xenon-136 2.11 ± 0.25 0.067 ± 0.0079
1024
seconds and beyond

13. FORMULA FOR DATING FOSSIL
SAMPLES BY C-14 DATING
 t = [ ln (Nf/No) / (-0.693) ] x t1/2
 t = [ ln (Nf/No) / (-0.693) ] x t1/2
 where ln is the natural logarithm, Nf/No is the percent of
carbon-14 in the sample compared to the amount in living
tissue, and t1/2 is the half-life of carbon-14 (5,700 years).
 So, if you had a fossil that had 10 percent carbon-14
compared to a living sample, then that fossil would be:
 t = [ ln (0.10) / (-0.693) ] x 5,700 years
 t = [ (-2.303) / (-0.693) ] x 5,700 years
 t = [ 3.323 ] x 5,700 years
 t = 18,940 years old
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14. THE DINOSAURIA EVOLUTIONARY
FOSSIL SERIES
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Pisanosarus appearence from 228-
216.5 my. The oldest known
Ornithischian
Thecolontosaurus appearece
from 216-200 ma. The most primitive
well known representative of the
sauropodomorph dinosarus.
Huayangosaurus.The
oldest and primitive known
Stegosaur.

15. Contd…
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Guanlong appearance 160ma.A genus
of Proceratosaurid tyrannosauroid
Dinosaur, one of the earliest known
examples of the Lineage
Falcarius appearance 126 my.
An early genus of Therizinosaur
Yinlong appearance 160 my. A genus
of basal Ceratopsian Dinosaur from the
Late Jurasic period of Central Asia.

16. Contd…
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Scelidosaurus appearance
208-194 my. One of the primitive
Thyreophorans.
Probactrosaurus appearance
130-125my. A possible ancestor of
the duck-billed Dinosaurs.

17. SCATTERED DINOSAURS BONES DATED BY
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18. FROZEN MAMMOTH THE FROZEN
CARCASS WAS DISCOVERED IN SIBERIA
DURING 1960.
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19. LIST OF HUMAN EVOLUTION
FOSSILS
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NAME AGE SPECI
ES
YEAR COUNTRY DISCOVERE
D BY
GEOLOGICA
L AGE
Sahelanthropu
s
tchaden
sis
7 Ma[2]
Sahela
nthrop
us
tchade
nsis
2011
CHAD Alain
Beauvilain,
Fanone
Gongdibe,
Mahamat
Adoum and
Ahounta
Djimdoumalb
aye
Late Miocene
(7-5.3 my)
Ardi
3.7Ma Ardip
ithec
us
rami
dus
1994 Ethiopia Yohannes
Haile
Selassie
Pliocene
(5.3-2.58
my)
NAME AGE SPECI
ES
YEAR COUNTRY DISCOVERE
D BY
GEOLOGICA
L AGE
Sahelanthropu
s
tchaden
sis
7 Ma
Sahela
nthrop
us
tchade
nsis
2011
CHAD Alain
Beauvilain,
Fanone
Gongdibe,
Mahamat
Adoum and
Ahounta
Djimdoumalb
aye
Late Miocene
(7-5.3 my)
Ardi
3.7Ma Ardip
ithec
us
rami
dus
1994 Ethiopia Yohannes
Haile
Selassie
Pliocene
(5.3-2.58
my)

20. Contd…
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NAME AGE SPECIES YEAR COUNT
RY
DICOVE
RED BY
GEOLO
GICAL
AGE
Steinhei
m skull
350k Homo
heidelbe
rgenis
1933 Germany - Pleistoc
ene
Lower
paleolit
hic(2.8-
3 my)
Peking
man
680-
780K
Homo
eructus
1921 China Davidson
Black
Pleistoc
ene
Lower
paleolit
hic(2.8-
3 my)

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Recently in Annigieri 100’s of human
skulls(without skeleton, only skulls?) found at
Annigieri Village during excavation ( Dharwad
District of N. Karnataka}
To find Reasons Historians sent samples for
dating C14 Method 150-200 years ago

22. LIMITATIONS
PURITY OF SAMPLES
ACCURACY OF THE
INSTRUMENTS
CALCULATIONS
RESTRICTED TO FEW FOSIIL CONDITIONS
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23. CONCLUSION
•Absolute dating is ultimate.
• Radio active method is applied for only certain
fossils.
• It suits only for insitu samples and not
universal
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24. REFERENCE
TEXT BOOK/ JOURNALS/ PERIODICALS/ INTERNET WEBSITES
FORMAT FOR REFERENCE
YEAR- AUTHOR(S) – TITLE – PUBLISHER- VOL. (ISSUE NO.) – Pp.
1.1963- RANKAMA K-PROGRESS IN ISOTOPE GEOLOGY-INTERSCIENCE
PUBLICATIONS A DIVISION OF JOHN WILEY & SONS. NEW YORK.
LONDON – Pp(22,188-192)
2. 1985-C.S.PICHAMUTHU-ARCHAEAN GEOLOGY –MOHAN PRIMLANI FOR
OXFORD & IBH PUBLISHING CO., Pp(95,96)
3.http//www.wikipedia.com/ list of human evolution fossils
4. http//www.google.com/anniegeri human skulls

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