reverse stratigraphy where older materials layers are found above more recent materials how Ex Chetro Ketl Chaco Canyon NM relative and absolute dating techniques in archaeology discard loss caching ritual interment cultural formation processes cultural deposition cultural disturbance reuse and reclamation natural formation processes alluvial colluvial aeolean which can cover artifacts which can move artifacts which can cause deflation turbation cid 127 mixing of deposits various types example of alluvial Cagny l Epinette relative dating law of superposition seriation absolute dating dendrochronology radiocarbon 14 C K Ar Luminsecence relative dating ordered in a sequence of earlier to later no specific dates cannot measure increments of time don t know how much earlier or later something occurred absolute dating date expressed in units of time specify a discrete interval of time an age range of years centuries or millennia law of superposition layers on the bottom were deposited earlier than those on top principle of super positioning laeotoli footprints objects in the bottom layers are older than objects in the upper layers cid 127 mary leaky discovered footprints in Tanzania 1976 hundreds of animal footprints buried below surface of Serengeti some were from at least two hominids bipedal hominids left footprints in volcanic ash dated ash layer above and ash layer below footprints date between 3 49 and 3 56 mya index fossil concept borrowed from geology paleontology life forms change through time time markers used in archaeology artifacts forms and styles change through time artifact styles are specific to certain times and places some distinct fossils are only found in specific layers of rock allowed strata with same diagnostic fossils to be correlated in time even if found in separate location strata in different sites with the same diagnostic artifacts belong to the same time period seriation a relative dating technique that relies on relative frequencies of a series of time markers styles change overtime initially there may be only a few users then a style will increase in popularity followed by a decline cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 Sir William Flinders Petrie late 19th century Egyptologist wanted to chronologically order Egyptian cemeteries cid 127 Extra Credit get website from email link complete exercise have it all correct print it out bring it to class cid 127 cid 127 cid 127 cid 127