Hi Lance, That sounds interesting for a start, although these would be lake situations. Could you provide a pdf of your study?

In fact some Russian colleagues have documented hard water effects for Lake Aral and the Caspian Sea, with 130 yrs and 450 yrs (!) offsets, but that was for molluscs, based on pre-war (i.e. pre-bomb) samples.

I found the paper - thanks.

I´m not sure about ecofacts - in any case not really what I would call artifacts. During excavation we do floatation of sediment for taking samples of (usually charred) botanic macro-remains. The recovered material is first studied by our (palaeo-)otanists and then we usually give some of the short-lived material for radiocarbon-dating (e.g. twigs - we want to avoid the "old-wood-effect" - juniper can become several hundred years old before being felled).

The problem is that we can date the archaeological material fairly precisely (sometimes), e.g. Greek sites can not exist in the area before the conquest by Alexander the Great in 329/328 BC, or Persian (Achaemenid) material can´t be there before the conquest by Cyrus, in the mid 7th Century BC. However, even the short-lived plant remains at such sites give C-14 ages that are too old, not just by a little, but by 70-200 years.

I observe that the "mistake" lessens the further I go downstream and away from the mountains.

Although we don´t really know enough about past climate in the region yet, at least some of the rivers are fed by glacier-water even today - so I started wondering whether possibly we have an old-water effect even in the short-lived plant remains. The natural precipitation is certainly insufficient for agriculture, which was practiced in Antiquity (we even know some of the canals) so mountain water was and still is certainly "fed" to the plants, even cereals.

My botanists think the explanation is a possibility, but others say that most of the carbon is taken up by plants through photosynthesis from the air - in that case clearly "old" water should not have any or only little effect.

I can´t really find precise studies with data on how much carbon in plants comes from water and how much from the air - thís would be quite an important aspect.

Just a suggestion, Nikolaus, but I am wondering if this might be an atmospheric effect. From what I’ve read you are doing your excavations in mountainous regions. Depending on the elevation of the site, this could mean that a reduction in atmospheric density. Which I know can cause a reduction in oxygen intake for humans, especially those not acclimatised to the altitude.

I’ve only done a very quick check, but the following extract may be of relevance:

“Any given volume of air is comprised of 79% nitrogen, 20.9% oxygen and 0.1% other gases such as argon and krypton. But as you get higher and higher above sea level, the pressure of the atmosphere decreases.

“This is due to the effects of gravity (which keeps air close to the ground) and heat (as you get closer to the sun) which cause molecules to bounce off one other and expand. So as you reach higher altitudes, the air expands.

“While the composition of the air stays the same, the expansion means that the air is ‘thinner’ – so in essence, at higher altitudes you inhale less oxygen and nitrogen molecules than you would at sea level.

“This drives a cascade of physiological responses in the human body. To begin with, your body increases its heart rate and respiratory rate to increase the amount of oxygen taken in and circulated around the body. So for example, while an athlete might normally run with a heart rate of 150 beats per minute, at high altitude it might increase to 165.

“Then the body begins to respond and adapt to the altitude (a process called acclimatization). More than 200 genes are turned on in response to altitude, and one that is most commonly thought of is that which induces the creation of more red blood cells thereby increasing the amount of hemoglobin in the blood.

“Hemoglobin is the protein that binds oxygen molecules to red blood cells. The more hemoglobin in the blood cells, the more efficient the cells will be at carrying oxygen around the body. This means that even though less oxygen is taken into the lungs, it is more easily transported to the muscles.

“Finally, as you breathe faster and faster, the amount of carbon dioxide in the blood is reduced, which leads to the blood becoming less acidic. To counter this, the kidneys release blood bicarbonate to try to balance the PH level. For athletes, this is a big advantage since blood bicarbonate is the primary source of protection for muscles against lactic acid – the waste that builds up during exercise and leaves muscles feeling stiff and sore.”

http://www.chiefscientist.gov.au/2011/05/running-on-thin-air/

This suggests that there may be changes to CO2 uptake in plants as well, at higher elevations, particularly, non-indigenous plants such as brought in crop plants. And given that gravity is an issue, and Carbon 14 is heavier that Carbon 12, I can’t help wondering if the proportions of both may be different at higher altitudes. Just a thought, but something you may want to explore.

Kathy

Dear Kathy, I´m late answering due to travels in regions where I didn´t have Internet. Thanks for your suggestion, which is an interesting idea. So far I haven´t found anything on the effect of altitude on C-14, which in fact forms under cosmic radiation in the atmosphere - so there might be something there. I´ll keep it in mind.

Hi Nikolaus,

I have a strong interest in your search as well.

I came at this question using a different approach when I learned about "SCIEM" (Synchronization of Civilizations in the Eastern Mediterranean during the mid-second millennium B.C.).

SCIEM is a panel of Egyptologists and Physicists who debate over whether they should take historical or carbon dates as authoritative. . . and, as far as I am aware, they lack the same data you are looking for.

The way I decided to approach the question was to use an indirect method of investigation known as "epidemiology" (first invented by John Snow back in 1854). The crux of the method is that if there is a systemic source of any anomaly, the anomaly itself will always manifest itself *around* the actual source of the anomaly.

Pretty common sense concept if you think about it, really.

Police officers use this method, for example, by plotting meth related incidences on a map-- the meth lab will almost always be found somewhere around the "epicenter" of where the meth related incidences are occurring.

The military uses the same method to catch terrorists (the weapons cache always tends to be at the "epicenter" of where the attacks are taking place).

The same thing is true with conflicts between carbon dating and historical dating methods in the Mediterranean-- the conflicts always occur right around the fault lines of areas that don't get enough annual rain fall.

Meaning the aquifers, or the "old water," is always at the "epicenter" of the conflict between these two dating methods (at least for SCIEM).

And it makes perfect sense, because dendronchronology is used to calibrate the carbon dating machine-- but the dendrochronology always comes from wild trees (which drink on rainfall), whilst the preferred carbon samples always come from domestic harvests (which drink on irrigated old water from the aquifers which run along the fault lines).

Plot all of your data conflicts on a map. . . it will provide you with a valuable trajectory in pin pointing exactly what the source of the anomalous data or "epidemic" is.

Dear Stephen,

Thanks for your suggestions, which are certainly useful. The "epidemiological" approach you describe is actually used quite often in archaeology, alhough usually to identify (ethnic) groups by material culture characteristics, and the application is controversial there for ethic reasons.

The major Problem in chronology for the region I am working in (Central Asia) is that we have a number of archaeological radiocarbon dates throughout prehistory (even if it could be more) but almost no dendrochronology to check them against. In the south, and for more historical periods (Achaemenids, Greeks, Medieval) we often have historical written data, but this is also uncertain to some degree. However, indeed there is a major discussion going on which data to believe ...

In my case, however, there seems to be a basic problem, which concerns both wild and cultivated plants (cereals and trees).

Since I posted the question we have done some more sampling and research - we now have a few juniper samples of up to ca. 500 years age (dendrochronology) from today (in fact 2013 - I am preparing the next trip for late May already). Besides the dendrochronological work of gradually building a "standard" curve, we have also done radiocarbon dating on selected rings from the early 19th and from the 17th century (i.e. before the nuclear bomb tests and before industrialisation of the region) - the radiocarbon dates are consistently around 200 years too old. It thus looks like we have some kind of "reservoir" or "old-water" effect working on both cultivated cereals and wild trees.

This is very important in archaeology, since 200 years is already a very significant offset, and it may have to be taken into account all over the Central Asian mountain areas (Kazakhstan, China, Tajikistan, Uzbekistan).

In any case, I am grateful for any further discussions and suggestions!

Any time Nikolaus,

It's actually reaffirming to hear that SCIEM is not the only department in the world dealing with this problem.

The radiocarbon dates are *also* 100-200 years older than the historical dates in SCIEM's neck of the woods (Eastern Mediterranean region during mid second Millenium B.C.).

So your quandary appears to be almost identical to SCIEM's-- but a different place, at a different time.

I always go with the historical dates that have an "anchor point" to a reliable astronomical observation made during a given dynasty, kingdom, or era.

Except, of course, in cases when the astronomical date yields a + or - range of 150+ years. . . and the carbon date, for the region in question, is above any suspicion of "old water" throwing the date off.

In that case, I'd go with carbon dating any day.

One of the important things to really look for when using Snow's epidemiology is data points that are out of place or don't follow the pattern-- focusing on them often yields the greatest insight. Big key is to always try to falsify, rather than confirm, a suspicion.

As a famous story goes, John Snow had figured out that it was the water from the well that was making people sick with cholera. . . but none of the local authorities in London would believe him. Then a women died in a region of the city that was completely removed from an otherwise consistent epidemic pattern.

At first blush, Snow thought the woman's death was evidence that he was wrong.

So Snow went to her house, specifically, to interview her family. There, he found out that she didn't like to drink from the well closest to them, but rather, traveled to get water from the same well that was making everybody sick.

The moral of the story is, take a closer look at data points that are out of place with an otherwise consistent "epidemic" pattern. . . they tend to offer the most insight upon closer inspection.