"This finding indicates that rings sometimes have been INCORRECTLY correlated with years, TOO GREAT AN AGE having been assigned from tree rings" (Willard F. Libby, "Accuracy of Radiocarbon Dates," Science, Vol. 140, No. 3564, April 19, 1963, p. 270).
"It has long been supported that tree rings are formed annually and so can be used to date trees. The studies of tree ring formation...have shown that this is NOT always so, as MORE than one ring may be formed in one year."Two growth layers, one THICK, the other THIN and lenticular, proved to be more common than one growth layer in this particular increment [that was studied]. THREE growth layers, in fact, were NOT unusual. A maximum of FIVE growth layers was discovered in the trunks and branches of two trees."It must be pointed out that these intraannuals were as distinctly and as sharply defined on the outer margin as any SINGLE annual increment" ("Anomalous Patterns in Tree Rings." Jan. 1963, Vol. 22, pp. 9, 13).
"Pertinent also is the well-known fact that standing snags of this species, other than those resulting from factors of gross destruction, are unknown. Does this mean that shortly preceding 3,275 years ago [or 4,000 years ago if John Muir's count was correct] ALL the then-living giant sequoias were WIPED OUT BY SOME CATASTROPHE?" (Edmund Schulman, "Longevity Under Adversity in Conifers," Science, Vol. 119, March 26, 1934, p. 399).