This method is useful for archaeologists working in areas where volcanic eruptions have left layers of ash above and below an archaeological deposit.

Aerial Reconnaissance - The technique of searching for sites and features, both cultural and natural, from the air, often using aerial photography or the human eye.It was characterized by large bifaces, particularly hand axes.This tool-making technology was a more complex way of making stone tools than the earlier Oldowan technology.Relative dating methods do not tell archaeologists exactly how old things are, but only how old things are relative to each other.Archaeologists work on the principle that objects at the bottom of an undisturbed were put there before objects that are above them, so objects found in the lower levels of a site are usually older than objects found in higher levels.It is important to remember that this method give the age of the mineral, not the artifact.So we can't pick up an artifact that's made from volcanic rock and get a potassium argon date on the artifact.When it comes to dating archaeological samples, several timescale problems arise.For example, Christian time counts the birth of Christ as the beginning, AD 1 (Anno Domini); everything that occurred before Christ is counted backwards from AD as BC (Before Christ).The contrast might also be drawn between two 'dimensions', the historical, and the archaeological, corresponding roughly to the short-term and long-term history envisaged by Fernand Braudel.On the one level, events and individuals are placed in an absolute chronology: the exact years and sometimes even months and days of the events and biographies are known.On the other level, the exact years may not be known, but it is known that one feature is earlier or later in relation to another; this is typically the case on an excavation, where the different archaeological strata allow objects found to be placed in a relative historical framework.For a long period in the 20th century Egyptian and Near Eastern chronology seemed to be the earliest of absolute chronologies, and imports from these areas were used to reconstruct the chronology of European prehistory.This method can give archaeologists an indication of the age of the artifacts in all Absolute dating methods can give an estimate of the real calendar age of an artifact or site.There are several absolute dating methods that archaeologists can use, including radiocarbon dating and potassium argon dating.potassium) decays into argon over time, so the age of certain rocks or minerals can be discovered by measuring the amount of argon they contain.