22nd April 2012, 11:42 AM
Best way to describe it is this.... from this forum. where they also discuss in more detail
but basically the interior of a long lived tree is already 'dead' so therefore any sample from that will be decades if not centuries earlier than the outer 'living' part of the tree However it all depends on what you want from your sample. but if you can recover twigs (recent in time to deposition) or bone/other organic frag (good because it is going to be a short lived organism like us) then that is better
http://www.bautforum.com/archive/index.php/t-72836.html
but basically the interior of a long lived tree is already 'dead' so therefore any sample from that will be decades if not centuries earlier than the outer 'living' part of the tree However it all depends on what you want from your sample. but if you can recover twigs (recent in time to deposition) or bone/other organic frag (good because it is going to be a short lived organism like us) then that is better
http://www.bautforum.com/archive/index.php/t-72836.html
Quote:The answer may be as simple as the way in which a tree absorbs c-14. Trees grow from the centre outwards, rendering the centre or 'heartwood' of the tree effectively dead tehreby unable to absorb further c-14 isotopes. The youngest part of the tree are the outer rings which will be larger than the inner rings thus absorbing larger quantities of c-14 isotopes than the inner heartwood. A single tree then - depending on its age - can provide an array of dates. If a 1,000 year old tree was felled today it will produce c-14 dates ranging from 2008AD to 1008AD. Thus we would find more c14 data with 2008 dates because the rings of the tree are larger. We would also find lower quantities of 1008 c14 dates because the rings would have been smaller whent he tree was much younger. So, it is entriely possible for one tree to produce a wide range of c14 dates.