Cross dating for dendrochronology
The above text is a snippet from Wikipedia: Dendrochronology and as such is available under the Creative Commons Attribution/Share-Alike License. We've got an app, with versions for i Phone, i Pod and (finally! Snap a picture of the QR code above, or simply follow this link for more info.Francis Heaney and Brendan Emmett Quigley, two of the best in the biz, have teamed up for Drunk Crosswords. It's free, and the quickest way to get help for your crosswords on the go. Archaeologists sometimes study the ring patterns in beams or other pieces of wood from archaeological sites to help date the sites; they may also study the ring patterns to infer the local climatic history.Tree-ring analysis requires observation and pattern recognition.
Even in relatively straightforward cases, all methods employed are sometimes found to produce spurious dates or to fail to identify a known correct match.
The Laboratory of Tree-Ring Research (LTRR) at the University of Arizona played a central role in the cross-pollination of these disciplines by providing the first wood samples of exactly known age for the early testing and establishment of the "Curve of Knowns" by Willard Libby.
From the 1950s into the early 1980s, LTRR continued to contribute dated wood samples (bristlecone pine and other wood species) to 14C research and development, including the discovery and characterization of de Vries/Suess "wiggles," calibration of the 14C timescale, and a variety of tests to understand the natural variability of 14C and to refine sample treatment for maximum accuracy.
Cross-dating is a technique used to take advantage of consistencies in stratigraphy between parts of a site or different sites, and objects or strata with a known relative chronology.
A specialized form of cross-dating, using animal and plant fossils, is known as biostratigraphy.