Science in Christian Perspective
Letter to the Editor
Tree Ring Dating
Vernon A. Raaflaub
Box 188 Nipawin,
Sask. SOE lEO Canada
From: JASA 26 (March 1974): 40
In a review by Clarence Menninga
of the books Why Not Creation? and Scientific Studies in Special
Creation, in the September 1973 Journal ASA, tree ring dating seems
to he accepted as quite valid, and in good agreement with historical and
Carbon-14 dating.
I am wondering if Menninga or some other ASA members might be interested in
doing some research for publication on tree ring dating. Several papers
published recently suggest some fallacies regarding the "agreement"
between Carbon-14, tree ring dating, and historically established dates. These
papers appear in the Spring-Summer 1973 issue of Pensee (published at Box
414, Portland, Oregon).
Thomas Mowles of the Lawrence Berkeley Laboratory ("Radiocarbon Dating and
Velikovskiao Catastrophism," page 22), states that "it is well known
that both the Egyptian and bristlecone pine calibrations drift substantially
before the late centuries B.C."
Dr. Herbert C. Sorenson, a chemist, charges ("The Ages of Bristlecoue
Pine," page 18), that "the construction of the bristlecone pine
chronology is at least partially dependent on radiocarbon dating." He says
that ".. . radiocarbon dating influences the dating of bristlecone pine
specimens and then these specimens are used to calibrate radiocarbon
dating." He points out that Fine Alpha is the only' one of the bristlecone
pines for which ring indices have been published. Only the master chronology has
been published; no correlations between one sample and another are available. He
writes: "Since no ring width data is available it is not possible to
independently check the published conclusions. Requests to obtain such data have
met with refusal:
'There were strong reasons why I published the chronology as a filtered series;
thus, I would not be able to release the index values to you."
Dr. Sorenson concludes that "there are stronger reasons" why a careful
and detailed investigation of the bristlecone pine chronology should be made,
and that at this time there are on compelling reasons to accept the bristlecone
pine chronology as valid.
In the same issue, Dr. W. F. Libby, originator of the Carbon-14 method, writes
("The Radiocarbon Dating Method" page 9f4, that the bristlecone pine
tree ring dating has made possible the determination of the extent of C-14
deviations, and that "we are driven back to the bistlecone pine method to
extend the chronology backward to glacial times about 11,000 years ago."
But if, as Sorensen holds, there is serious reason to question the correlation
of successively overlapping distinctive ring patterns, we may be left with
inaccurate radiocarbon dates. Sorenson writes:
"samples with a high proportion of missing rings will exhibit complacent
ring patterns. It is not surprising, then, to find that nearly 50 percent of the
bristlecone pine samples used as components in the 7104-year master chronology
have mean sensitivities of less than 0.30 (5). Such low sensitivities are
suggestive of complacent samples that would cross match about the same
regardless of where they were placed in the chronology" (pages 17, 18).
I think the time is ripe for a careful evaluation of tree ring dating so we can
know whether it has a valid chronology or not.