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we would expect their growth was
limitcd by sorne climatic factor–
usually rainfall.
Dendrochronologists Dr. Valmore
C.
LaMarche and Dr. Harold
C.
Fritts have demonstrated that we
can acqu ire a greater understanding
of clima tic fluctuations and weather
pa tterns over the past severa! thou–
sand ycars by examining bristlecone
tree-ring patterns. Such studies. they
believe. give valuable insights into
future climatic trends, such as the
potentia! for a new ice age.
Recallbrating Carbon 14
Yet pcrhaps the most significan! re–
sult of the bristlecone pine tree-ring
chronology is its revolutionary im–
plications for the carbon-14 dating
method and our understanding of
prehistOry.
What do bristlecone pines have to
do with carbon 14? Allliving things,
including the bristlecone pine, con–
tain a small amount of the radio–
active elcment carbon 14. When an
organism dies, the carbon 14 begins
to decay at a known rate. By mea–
suring the amount of remaining car–
bon 14 in a once living organism,
scientists can closely estímate when
that organism died.
But the radiocarbon dating tech–
nique is based on tbe questionable
assumption that the amount of car–
bon 14 available to be incorporated
into living organisms has remained
constan! for thousands of years.
Since carbon-14 concentrations
have been measured only in the past
four decades, scientists could only
assume
that the same carbon-14
concentration applied to those past
eras where no historical data was
available as a check. Indeed. with–
out that assumption, or at least
sorne method of calibration. the ra–
diocarbon dating method would be
largely worthless.
Enter bristlecone pine. The 8.200-
year sequence of bristlecone rings
has provided a remarkable check on
the primary assumption of radio–
carbon dating. As eacb ring in a
sequence grew, it recorded the car–
bon-14 concentration in the atmo–
sphere at that time. By measuring
the carbon- 14 content of various
rings. scientists were able to check
the accuracy of the radiocarbon dat–
ing method. The conclusion of
The
PLAIN TRUTH December 1977
many ycars of research at the Uni–
versities of Arizona. Pennsylvania,
and California is that the basic as–
sumption of radiocarbon dating is
no1
grossly in error. lndeed, the
bristlecone studies have shown that
radiocarbon dating is generally ac–
curate over the past 3,000 years.
Older by 900 Years
But the bristlecone calibration also
produced something unexpected:
As we go back in time prior to about
1,000 B.
C.,
the amount of carbon 14
in the environment was somewhat
grea1er
than at present. This means
that certain samples dated by radio–
carbon will be dated
loo young.
In
other words, thc bristlecone pine
calibration has shown that sorne ar–
chaeological sa mples should ac–
tually be dated up lo 900 years older
(earlier) than conventional carbon-
14 analysis would indicate!
The bristlccone calibration of ra–
diocarbon ha drastically changed
the archaeologist's understanding of
sorne early cultures. especially in
Europe. A leading British archae–
ologist, Colín Rcnfrew. believes the
bristlecone pine will revolutionize
our chronology of the development
of early European civilization.
Using the calibrated radiocarbon
dates, Renfrew contends that me–
galithic tombs of western Europe
are actually
older
than the Egyptian
pyramids (which are usually
thought to predate the European
tombs). He also asserts that Britain's
Stonehengc, once thought to have
been insp ired by Mycenaean
(O reek) bui lders, actually was com–
pleted well before the Mycenaean
civilization began. "Now it is clear."
says Renfrew, "that megalithic
chamber tombs were being built in
Brittany ... a millennium before
monumental funerary architecture
first appears in the eastern Mediter–
ranean and 1500 years before the
raising of the pyramids."
Multlple Rlngs and the
Appearance of Age
According to Renfrew, the bristle–
cone calibration makes obsolete the
formerly accepted theory that pre–
historic culture began in the Near
East and was only la ter diffused into
"barbarie" Europe.
(Continued on page 37)
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