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Archaeological
Dating
Methods
archaeological
dating methods
1. relative dating (aka “older/younger”
dating)
2. chronometric dating
(aka “absolute” dating)
Relative and Chronometric Dating
Understanding Humans, 10th Ed., p. 189.
Understanding Humans, 10th Ed., p. 188.
REMEMBER: relative
methods
tell you whether something is
older / younger / the same age
methods
Understanding Humans, 10th Ed., p. 188.
REMEMBER: chronometric
methods
yield a date
often scaled in calendar years
+/- a number of years (there is a
margin of error in every technique)
Stratigraphy
the sequence of geological strata, or layers, formed
by materials deposited by water or wind
-Law of association
-Law of superposition
Otero, S. (2004) Social and Behavioural Science Lecture
Notes (2014). El Camino College, Torrance, California
Main gorge at Olduvai. Note geological beds.
Understanding Humans, 10th Ed., p. 197.
Hoebel, Anthropology: The Study of Man and Archaeology, 4th Ed., p. 153.
Olduvai Gorge, Kenya.
Bed I
Note how stratigraphy is used to date
stone tools
archaeological
dating methods
1. relative dating
2. chronometric dating
(aka “absolute” dating)
provides estimates in actual numbers of
years
(sometimes +/-)
Relative and Chronometric Dating
Understanding Humans, 10th Ed., p. 189.
chronometric dating
(aka “absolute” dating)
determining the actual age of geological deposits (and the
fossils in them) by examining the chemical composition of
rock fragments and organic remains containing radioactive
substances such as uranium 238, and C 14, which decays at
a known rate. It is a destructive method.
Direct determination of age determined
through laboratory analysis
Here are three examples you need to know:
C14 dating of organic samples
Dendrochronology (tree ring patterns)
Molecular clocks (slight genetic markers that change at a
known rate)
Relative and Chronometric Dating
Understanding Humans, 10th Ed., p. 189.
Technician in a radiocarbon dating laboratory.
Understanding Humans, 10th Ed., p. 194.
Radiocarbon dating:
Don’t stress out; I will
NEVER ask you to
explain how it works
• Method was developed in the
1940’s by Willard Libby and a team
of scientists at the University of
Chicago.
• Very powerful in dating artifacts
and geological events up to about
50,000 years ago.
So, if relative dating techniques
do not give you a specific age
and chronometric dates give
you a date range, how do
archaeologists choose which
dating technique to use?