Archaeological Discovery In Kakadu

[PaulP]

DJC, is this of interest ?

It sounds significant, but I'm not qualified enough to say.

http://www.smh.com.au/federal-politics/p...xe3qy.html

[Robblues]

Certainly interesting, as in most cases the more they did the more you hope to find & tells a bigger story of the past, thanks for sharing

[DJC]

Significant, but inevitable as dating techniques improve and more occupation sites are investigated.

There is a probable occupation site (a shell midden) at Warrnambool that has a 60,000 date.  Many archaeologists doubted that the shellfish were the remains of human meals because it was older than sites in northern Australia.  Now it fits the likely colonisation model.

DNA evidence suggests that the ancestral Aboriginal people left Africa around 70,000 years and 5,000 years to get from Africa to Australia seems reasonable.

We have a pretty impressive cultural history in this country.  In time it will be embraced by most Aussies 

[Baggers]

Significant, but inevitable as dating techniques improve and more occupation sites are investigated.

There is a probable occupation site (a shell midden) at Warrnambool that has a 60,000 date.  Many archaeologists doubted that the shellfish were the remains of human meals because it was older than sites in northern Australia.  Now it fits the likely colonisation model.

DNA evidence suggests that the ancestral Aboriginal people left Africa around 70,000 years and 5,000 years to get from Africa to Australia seems reasonable.

We have a pretty impressive cultural history in this country.  In time it will be embraced by most Aussies 

Hear, hear!

[Professer E]

CL dating, wonder what the two sigma error bars are....

[DJC]

Optically Stimulated Luminescence (OSL) dating determines when grains of sand were last exposed to sunlight.  Radiocarbon dating requires organic material (that often doesn't survive) and is not very reliable once you get past 45,000 years.

I'm not really familiar with the technology but I know that often only a couple of grains of sand in a  100gm sample will give reliable results.

[Professer E]

Any scientist worth their salt publishes the uncertainty estimates, it's a key part of geochronolgy, or other quantitative technique for that matter.

C14 dating is unreliable post about 45 k due to the half lives of the radiogenic system.  After that time the there isn't enough to measure... Analytical uncertainty exceeds instrumental precision.

[flyboy77]

Any scientist worth their salt publishes the uncertainty estimates, it's a key part of geochronolgy, or other quantitative technique for that matter.

C14 dating is unreliable post about 45 k due to the half lives of the radiogenic system.  After that time the there isn't enough to measure... Analytical uncertainty exceeds instrumental precision.

yeah, the +/- numbers (error range) is always useful - unless you're a climate scientist!

[Thryleon]

Any scientist worth their salt publishes the uncertainty estimates, it's a key part of geochronolgy, or other quantitative technique for that matter.

C14 dating is unreliable post about 45 k due to the half lives of the radiogenic system.  After that time the there isn't enough to measure... Analytical uncertainty exceeds instrumental precision.

Ive also heard that C14 dating fails to take into account the rate of change of Carbon in the atmosphere, and makes the assumption that it is today what it was when the item is being dated.

I dont know much about this stuff, but I am always fascinated to learn about cultural history.

[DJC]

Ive also heard that C14 dating fails to take into account the rate of change of Carbon in the atmosphere, and makes the assumption that it is today what it was when the item is being dated.

I dont know much about this stuff, but I am always fascinated to learn about cultural history.

Radiocarbon dates are calibrated to take into account fluctuations in atmospheric CO2.

If I remember correctly, there's a 66% probability that the actual age of the object being dated falling within the + or - range.

There are strict conventions about publishing radiocarbon and other radiometric dates.