The study of the past is to understand the human behavioural activities and cultural progress in a sequential order based on tangible and intangible evidences in a given socio-economic-cultural context. The Archaeological data has to be placed in a chronological order to understand this sequential cultural process. For this, various dating methods are being used in the archaeological investigations.

1. ABSOLUTE DATING METHODS
IN ARCHAEOLOGY
Unraveling the Timeline of Human History
BY
Dr. Rajiv Kumar Jaiswal
Assistant Professor
Dept. of AIHC & Archaeology
Vasanta College for Women
KFI, Rajghat Fort
BHU, Varanasi

2. INTRODUCTION TO DATING METHODS
 The study of the past is to understand the human behavioural activities
and cultural progress in a sequential order based on tangible and
intangible evidences in a given socio-economic-cultural context.
 The Archaeological data has to be placed in a chronological order to
understand this sequential cultural process.
 For this, various dating methods are being used in the archaeological
investigations.

3. IMPORTANCE OF DATING METHODS IN
ARCHAEOLOGY
 Dating in archaeology is crucial for several reasons:
• Chronology Establishment: Dating allows archaeologists to establish the
chronological order of artifacts, sites, and cultural phenomena. This
chronological framework is essential for understanding the sequence of events
in human history and the development of cultures.
• Interpretation of Cultural Change: By dating artifacts and sites,
archaeologists can track changes in material culture over time. This helps in
interpreting shifts in technology, social organization, economy, and ideology,
providing insights into how societies evolve and interact.

4. CONT….
• Contextual Understanding: Dating helps archaeologists place
artifacts and sites within their historical and cultural context.
• Cross-Cultural Comparisons: Dating methods enable
archaeologists to compare the development of different cultures
and regions. By establishing timelines, researchers can identify
similarities, differences, and connections between various societies

5. DATING TECHNIQUES
 Dating techniques in archaeology are diverse, ranging from relative methods that
provide a sequence of events without precise dates to absolute methods that assign
specific chronological ages to artifacts and sites. Here's an introduction to some of
the key dating techniques:
1. Relative Dating Methods
2. Absolute Dating Methods

6. DATING TECHNIQUES
Relative Dating Techniques
I. Stratigraphy
II. Typology
III. Pollen Analysis
IV. Geo-chronology
V. Fluorine Test
VI. Nitrogen Test
VII. Seriation
VIII.Varve
Absolute Dating Techniques
I. Radio-carbon (C-14)
II. Thermo-luminescence (TL)
III. Potassium-Argon (K-Ar)
IV. Dendro-chronology (Tree-ring)
V. Obsidian Hydration
VI. Fission-track
VII. Electron spin resonance (ESR)
VIII.Uranuim series

9. Absolute Dating Techniques
I. Radio-carbon (C-14)
II. Thermo-luminescence (TL)
III.Potassium-Argon (K-Ar)
IV.Dendro-chronology (Tree-ring)
V. Obsidian Hydration
VI.Fission-track
VII.Electron Spin Resonance (ESR)
VIII.Uranium series
Absolute dating techniques fall under
major four processes, namely
radioactive processes, chemical
processes, geological processes and
biological processes.
1. Radiocarbon, potassium-argon,
uranium-lead, thorium-lead,
fission track, TL, OSL and ESR fall
under radioactive processes.
2. Amino acid and obsidian hydration
come under chemical processes.
3. Archaeo-magnetism come under
geological processes.
4. Dendrochronology come under
biological processes.

10. INTRODUCTION TO RADIOCARBON DATING
 The radiocarbon dating has changed the
face of the archaeological research.
 It has made a revolutionary impact in the
fields of archaeology and Quaternary
science.
 Willard F. Libby developed this method in
1948 as spin-off from atomic research
during second world war.
 Since then, it remains the most widely
used dating techniques in modern
archaeology.
 Half-life of C-14 is 5730±40.
10
Rajiv Kumar Jaiswal

11. FORMATION OF CARBON-14
 Carbon-14 is a rare, radioactive isotope of carbon that forms in the
upper atmosphere when cosmic rays collide with nitrogen atoms,
producing carbon-14 atoms. These carbon-14 atoms then combine
with oxygen to form carbon dioxide (CO2).
 Carbon-14 is incorporated into the cells of all living organisms
through processes like photosynthesis (in plants) or consumption of
plants and other animals (in animals). As long as an organism is
alive and continues to consume food and exchange gases with the
atmosphere, the ratio of carbon-14 to stable carbon isotopes (carbon-
12 and carbon-13) in its tissues remains relatively constant.
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12. Rajiv Kumar Jaiswal 12

13. RECOMMENDED MINIMUM AMOUNT OF
SAMPLE
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15. APPLICATIONS OF RADIOCARBON DATING IN
ARCHAEOLOGY
Rajiv Kumar Jaiswal 15
Radiocarbon dating has numerous applications in archaeology, offering
invaluable insights into the timing and sequence of events in human
history. Some of the key applications include:
• Dating Organic Artifacts
• Establishing Chronologies
• Determining Site Occupation Periods
• Dating Human Remains
• Studying Cultural Evolution
• Reconstructing Paleo-environments
• Refining Historical Chronologies

16. ACCELERATOR MASS SPECTROMETRY (AMS)
• Accelerator Mass Spectrometry (AMS) is a technique used for
measuring the concentration of rare isotopes that cannot be detected
with conventional spectrometers.
• AMS is a highly sensitive method of counting atoms. It has the
capacity to separate and measure rare isotopes from an abundant
neighbouring mass. In the sense, it separate and measure the C-14
from C-12.

17. CONTRIBUTION OF C-14 IN INDIAN
ARCHAEOLOGY
Rajiv Kumar Jaiswal 17
 Radiocarbon dating has been widely applied to Indian archaeological
sites across various periods and regions, contributing to our
understanding of India's rich cultural history.
 Several prominent Indian archaeological sites have been dated using
radiocarbon dating methods, including sites associated with the
Prehistoric sites like Chopani mando, Jhunsi, Koldihwa, Lahuradewa,
 Indus-Saraswati Civilization (such as Dholavira, Lothal, Rakhigarhi
and Kalibangan),
 Early historic sites (such as Rajghat, Sarnath, Sanchi and Aktha),
 Megalithic sites, Rock art sites, Iron age sites (such as Malhar, Raja-
Nal-ka Tila, Dadupur) and many others spanning different periods and
cultural contexts.

18. C-14 labs in India
Birbal Sahani Institute of Palaeobotany (BSIP) at Lucknow in
Uttar Pradesh
Physical Research Laboratory (PRL) at Ahmedabad, In Gujrat
Institute of Physics at Bhubanehswar in Orissa
National Geophysical Research Institute (NGRI) at Hyderabad
in Telangana
Inter University Accelerator Centre (IUAC) in New Delhi.
Rajiv Kumar Jaiswal 18

19. THERMO-LUMINESCENCE DATING
• Thermo-luminescence dating is a method used to determine the age of
archaeological materials, primarily pottery or burnt flint, by measuring the
amount of accumulated radiation-induced electrons trapped in the crystal lattice
of minerals, such as quartz or feldspar, during their exposure to natural
radiation in the environment.
• How TL dating works:
Radiation Exposure
Heating Event
Measurement of Light Emission
Age Calculation

21. CONT….
• TL dating is particularly useful for dating pottery, ceramic
objects, and burnt flint found at archaeological sites where
organic materials for radiocarbon dating are not available
or are not well-preserved. It provides valuable chronological
information about human occupations, technological
developments, and environmental changes in the past.
• When the light (optic) is used instead of heat (thermo) to
released the accumulated electrons, then it is called
Optically Stimulated Luminescence (OSL).

22. POTASSIUM-ARGON (K-AR) DATING
• Potassium-Argon (K-Ar) dating is a geochronological method used to
determine the age of rocks and minerals based on the decay of radioactive
potassium-40 (K-40) to argon-40 (Ar-40) within the mineral's crystal lattice.
This method is particularly useful for dating volcanic rocks and minerals, as
they often contain potassium-bearing minerals, such as micas, feldspars, and
volcanic glass, suitable for K-Ar dating.
• potassium-argon dating is a powerful geochronological tool that has
significantly contributed to our understanding of Earth's history, the timing
of geological events, and the processes of rock formation and alteration.

24. DENDRO-CHRONOLOGY
• Dendrochronology is a dating method that uses the analysis of tree rings to determine the age
of wooden objects, archaeological artifacts, and environmental changes over time. Here's how
dendrochronology works:
• Formation of Tree Rings: Each year, trees in temperate and boreal regions produce a new layer
of growth, or tree ring. The width, density, and other characteristics of these rings are
influenced by various factors, including climate, soil conditions, and tree physiology.
• Pattern of Tree Rings: By analyzing the pattern of rings in a tree's growth, dendr-
ochronologists can identify sequences of wide and narrow rings unique to each tree.
• Dating Wooden Objects: Dendrochronology can be used to date wooden objects, such as
archaeological artifacts, buildings, or artworks, by comparing their ring patterns to master
chronologies.
• Climate and Environmental Reconstruction: Dendrochronology provides valuable information
about past climate and environmental conditions. By analyzing tree ring widths, isotopic
composition, and other parameters, researchers can reconstruct past climate variability,
including temperature, precipitation, and drought events.

25. CONT….
• In summary, dendrochronology is a powerful dating method
that relies on the analysis of tree rings to establish precise
chronologies and reconstruct environmental histories. Its
ability to provide accurate dates and detailed environmental
information makes it an invaluable tool for understanding
past human societies and natural ecosystems.

27. OBSIDIAN HYDRATION
• Obsidian hydration dating is a dating technique used to estimate the
age of obsidian artifacts based on the thickness of the hydration rind
that forms on their surface over time. Obsidian is a natural volcanic
glass that was widely used by past societies for making tools, weapons,
and ornaments due to its sharp edges and ease of shaping.
• Hydration Process: When obsidian is exposed to air, water molecules
gradually diffuse into its surface through a process known as hydration.
• Thickness of Hydration Rind: The rate of hydration depends on factors
such as temperature, humidity, and the chemical composition of the
obsidian.

29. FISSION-TRACK DATING
• The natural splitting (fission) of uranium-238 (U-238) atoms present in obsidian and
other volcanic minerals leaves traces of called fission tracks. These fission tracks are
erased once the mineral is heated above a critical temperature.
• During volcanic eruption, all fission tracks present in the minerals are removed.
This sets the clock to zero. However, the fission tracks again started appearing once
the material cooled down.
• The density of uranium-238 fission tracks is proportional to the time elapsed since
the sample was last heated. The date is determined by calculating the presence of
the fission tracks.

30. ELECTRON SPIN RESONANCE (ESR)
• Electron spin resonance (ESR) dating is a geochronological method used to determine the age of
materials containing unpaired electrons, such as tooth enamel, quartz, and fossilized shells, by
measuring the accumulation of trapped electrons over time due to exposure to natural
radiation. Here's how ESR dating works:
• Trapping of Electrons: When minerals or materials containing unpaired electrons are exposed
to natural radiation in the environment, electrons become trapped in defects or imperfections
within the crystal lattice. These trapped electrons are typically free radicals or paramagnetic
species.
• Stable and Unstable Centers: Within the crystal lattice, trapped electrons may occupy both
stable and unstable centers. Stable centers retain trapped electrons for long periods, while
unstable centers release trapped electrons upon exposure to light or heat.
• Accumulation of Trapped Electrons: Over time, additional trapped electrons accumulate in the
material's crystal lattice due to ongoing exposure to natural radiation. The number of trapped
electrons increases with the duration of exposure and is proportional to the age of the material.

32. URANIUM SERIES DATING
• Uranium series dating is a radiometric dating method used to determine the age of calcium
carbonate materials, such as speleothems (e.g., stalagmites, stalactites), corals, and mollusk
shells, by measuring the radioactive decay of uranium isotopes and their daughter products
within the mineral matrix. This dating method is particularly useful for dating materials that
have formed in water-rich environments, such as caves, oceans, and lakes. Here's how
uranium series dating works:
• Uranium Decay Series: Uranium series dating relies on the radioactive decay of uranium
isotopes (^238U, ^235U, and ^234U) and their subsequent decay products. Uranium-238
(^238U) decays through a series of radioactive decay steps to eventually form stable lead-206
(^206Pb). Similarly, uranium-235 (^235U) and uranium-234 (^234U) also undergo radioactive
decay to form lead isotopes (^207Pb and ^230Th, respectively).
• In summary, uranium series dating provides valuable chronological information about calcium
carbonate materials and their formation history, contributing to our understanding of past
environmental and geological processes.