Archaeological Discovery In Kakadu

[Professer E]

Correct.  Ages are normally quoted at 95% confidence levels (standard deviations) or 2 sigma values.

C14 has been corrected using dendrochronology, ice cores and oxygen isotopes (partitioning of atmospheric gases are temperature dependent).  It's a robust technique.

Problem with most chronological work is not the technique, but the sample it is applied to.

[DJC]

The people involved in this work will be giving a paper at the Australian Archaeological Association conference in Melbourne in December.  It should be interesting.

[DJC]

I should have mentioned some of the stone tool discoveries.

Edge ground tools or stone axes are generally associated with early agriculture and are usually found in sites less than 10,000 years old.  Aboriginal people had stone axes well before that (>20,000) but this site pushes the earliest stone axes much further back.

Other artefacts indicate a seed grinding technology.  Once again something that is usually associated with agriculture or in the relatively recent past in Australia.

[LP]

How do they differentiate on digs if stuff might have been buried deeper by actions unknown to the investigators?

I understand deep digs, but shallow digs like this?

Would sediment moved by flood be optically reset?

[DJC]

How do they differentiate on digs if stuff might have been buried deeper by actions unknown to the investigators?

I understand deep digs, but shallow digs like this?

Would sediment moved by flood be optically reset?

Missed your question LP.

That's a science in itself and it's called taphonomy.  One thing that good archaeologists will do is look for conjoins, that is, two or more chips from stone tool manufacture that fit back together.  Conjoins lying close together indicate not much post-depositional movement.  If they are separated by considerable depth then the deposits are likely to have been disturbed.

All archaeological deposits are disturbed by subsequent human activity, burrowing animals, roots, erosion and many other factors.  Understanding that disturbance is the key to good archaeology.

Sand grains are optically reset by exposure to sunlight.  If flood waters scoured part of the site away 5,000 years ago, the exposed sand grains would be reset at 5,000 years.  Any archaeologist worth her salt would recognise that disturbance.

[LP]

Missed your question LP.

That's a science in itself and it's called taphonomy.  One thing that good archaeologists will do is look for conjoins, that is, two or more chips from stone tool manufacture that fit back together.  Conjoins lying close together indicate not much post-depositional movement.  If they are separated by considerable depth then the deposits are likely to have been disturbed.

All archaeological deposits are disturbed by subsequent human activity, burrowing animals, roots, erosion and many other factors.  Understanding that disturbance is the key to good archaeology.

Sand grains are optically reset by exposure to sunlight.  If flood waters scoured part of the site away 5,000 years ago, the exposed sand grains would be reset at 5,000 years.  Any archaeologist worth her salt would recognise that disturbance.

Cheers DJC, thanks for the explanation.