All of the artifacts in a given stratum will be of approximately the same age, while those in strata above or below will be younger or older respectively.Cross-dating can indirectly establish a date for artifacts and sites.Similarly, materials of human origin are also deposited onto the earth’s surface.In archaeological sites, natural and human-generated materials occur together in layers.This is probably the most fundamental and important aspect of tree ring research.In essence, crossdating involves a form of pattern matching. Natural materials such as rocks, soil, and traces of plants and animals settle on the earth’s surface and over time can accumulate in layers.
Interestingly these rings are more than a temperature indicator, they also tell the researcher about moisture and cloudiness as well.Dendrochronology is the study of climate change as recorded by tree growth rings.Each year, trees add a layer of growth between the older wood and the bark.In his Trattato della Pittura (Treatise on Painting), Leonardo da Vinci was the first person to mention that trees form rings annually and that their thickness is determined by the conditions under which they grew. S., Alexander Catlin Twining (1801–1884) suggested in 1833 that patterns among tree rings could be used to synchronize the dendrochronologies of various trees and thereby to reconstruct past climates across entire regions.During the latter half of the nineteenth century, the scientific study of tree rings and the application of dendrochronology began.It is also used in radiocarbon dating to calibrate radiocarbon ages.New growth in trees occurs in a layer of cells near the bark.Please consult Field Methods for a detailed description of the field equipment, including its use and care, and the actual methods of core collection and preservation. The cores should next be mounted and glued in to increment core holders and then the surface prepared for study following the protocols outlined in Lab Methods.Following surface preparation, you can begin the process of crossdating.This layer, or ring as seen in cross section, can be wide, recording a wet season, or narrow, recording a dry growing season.Because the rings are basically recording a good growing season or a bad growing season, they are indirectly recording more than just moisture.