Since cross-dating depends on matching the high-frequency elements of a sample against a master chronology, various methods are explored for removing the low-frequency variance in ring-width series before they are compared.
During the latter half of the nineteenth century, the scientific study of tree rings and the application of dendrochronology began.In 1859, the German-American Jacob Kuechler (1823–1893) used crossdating to examine oaks (Quercus stellata) in order to study the record of climate in western Texas.Dendrochronology is useful for determining the timing of events and rates of change in the environment (most prominently climate) and also in works of art and architecture, such as old panel paintings on wood, buildings, etc.It is also used in radiocarbon dating to calibrate radiocarbon ages.In this particular exercise, we wish to examine whether there is a relationship between local climate (precipitation) and tree rings using white oak (Quercus alba) in southeastern Ohio.
Each field team should obtain the appropriate field supplies from their instructor and obtain 3 increment cores from white oak trees at the chosen field site.
During the first half of the 20th century, the astronomer A. Douglass founded the Laboratory of Tree-Ring Research at the University of Arizona.
Douglass sought to better understand cycles of sunspot activity and reasoned that changes in solar activity would affect climate patterns on earth, which would subsequently be recorded by tree-ring growth patterns (i.e., sunspots → climate → tree rings).
I strongly suggest you follow all the steps at this site and then practice using the tutorial at step 12.
At this point, all of the increment cores have been crossdated and verified and you should have a ring width measurement for every ring in every core that you collected.
This is calculated by first deriving the probability of achieving an observed correlation coefficient from a single matching experiment, and then allowing for the fact that, when two series are compared at many overlap positions, a multitude of tests is performed.