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.