"Recent use of dendrochronology for calibration of radiocarbon-derived dates suggests that they deviate increasingly from actual calendar dates, from an error of about 200 years at 1000 B.C. up to an error of about 900 years at 5,000 radiocarbon years B.C. . .Although calibration curves are designed to bring radiocarbon dates in line with actual dates, the limits of these curves currently do not extend earlier than about 5200 B.C."
A. Bernard Knapp, The History and Culture of Ancient Western Asia and Egypt, Belmont, California: Wadsworth Publishing Company, 1988, 7