Archaeology News: Meghalayan Age, First Bread, & more

[Brian G Turner]

I was thinking about these previously recorded climate change events, and am left puzzling over them.

My original puzzle is that Orkney reportedly used to be a warmer place, and had lower sea-levels. That confuses me, because I struggle to imagine how the climate of North of Scotland could have been warmer, yet sea levels not be higher. Even more so because the crust beneath North Scotland is even still rising - effectively, rebounding after the weight of glaciers during the last ice age.

That got me thinking about the change in climate that occurred around 4,000 BC - effectively turning the Sahara from Savannah to desert. IMO that's a key climate event, which seems to suggest a shift of climate north or south - but no clear explanation of what or why on a global scale, and what that would have meant elsewhere on Earth. (Presumably this is when Neolithic Orkney was warmer and better suited for habitation.)

Recently I've been reading about how during the Bronze Age in Britain (around 2,500BC to 800BC) also shows evidence of an extremely long period of warmer and drier climate in Britain - cultivation could occur at much higher latitudes, and areas of Britain that are now moorland sometimes show clear evidence of successful Bronze Age farming (at Dartmoor and Exmoor, for example) - before the climate became colder and wetter, forcing farming down to lower latitudes.

And then I think of the original dating system at the start of the original post, and am left wondering why they focus on around 1,200BC as a key boundary, and not the others. Also, I can't shake the feeling that the 1200BC climate change was not an ordinary climate change cycle event but was triggered by a sudden cause such as vulcanism or even an impact event.

So, overall, I'm left puzzled by the extent of past climate change, whether the Egyptian and British Bronze-Age events were also part of a general cycle or due to a sudden event, and whether the dating suggested in the original post might have misunderstood the processes involved completely.

Am going to have to do some research on this. (

 

[Brian G Turner]

Ok, so reading on Wikipedia the Sahara was green during the African Humid Period, which was caused by the precession of the Earth. Presumably, Orkney could be warmer and have lower sea levels because it would still take a significant amount of time for ice-caps to melt (though I'm surprised by the idea that thousands of years of warm activity would not lead to a significant change in sea-levels when you think about the situation today - unless this is exactly what caused sea-level rises, such as the flooding of the North Sea, in the first place...).

 

[Brian G Turner]

Interesting - an article at The Guardian states that the main religious centre at Orkney was abandoned around 2,200 BC - which coincides with the Meghalayan Age - which of course is a thousand years before the bronze age collapse in the Mediterranean and was an error on my part. Neolithic discovery: why Orkney is the centre of ancient Britain

 

[Brian G Turner]

Meghalayan - a period beginning around 4,200 years, underlined by major droughts that caused the collapse of major civilizations worldwide, presumably due to changes in ocean and atmospheric currents. Formal subdivision of the Holocene Series/Epoch

I've emailed The International Commission on Stratigraphy on this, because the date they provide - equivalent to 2250BC - is out by 1,000 years. 2250BC would put this social collapse at the end of the stone age, whereas the the great Bronze Age collapse actually occurred around 1100BC, not 2250BC: The collapse of Bronze Age civilisation

I did wonder about this when I first posted it, but recently I've been reading about the Bronze Age collapse so decided to revisit this subject and see if the date has been revised, but it hasn't. Not yet.

 

[Brian G Turner]

Well, that's interesting - the reply I got was:

"The date of this boundary is not based on cultural events, but on a speleothem age determined independently of human cultures"

Which is surprising, because the news at the time was that the Meghalayan age was determined specifically by its effect on human culture, giving rise to a debate within geology whether that was acceptable or not: Welcome to the Meghalayan Age

Interestingly, historians waded on, which angered the geologists: Historian angers group who proposed labeling late Holocene as Meghalayan Age

However, if the geologists are claiming that "mega-drought resulted in the collapse of a number of civilizations—in Greece, Mesopotamia, Syria, Egypt, Palestine, the Yangtze River Valley and the Indus Valley" then indeed they are out by 1,000 years.

EDIT: I can't find any real mention online on what these catastrophic events appear to be, other than growth on one stalagmite in a cave in the Meghalayan region of India. I find no mention of anything else other than this local event, though this appears to be the original paper, but I don't have access to it: Error - Cookies Turned Off

EDIT 2: No, that's not the original paper, simply one cited as showing evidence of a boundary at 2,200 BC published in 2012, not 2018 when the date was accepted. And here's another piece talking about the arguments raging between geologists over this, with some referring to it as a Python-esque "Ministry of Silly Cuts":
Geology’s Timekeepers Are Feuding

However, most of that article talks about the debate over including an Anthropocene period.

Going back to the originally release, it specifically mentions that the Meghalayan boundary had a major effect on human civilization - but that statement is completely wrong. The irony is that the data claims catastrophic change in India at the very least - and yet 2,200BC occurs at the height of the Harrupian civilization in India, not it's collapse - which, again, was 1,000 years later.

EDIT 3: It's possible that the history issue came from a press release gone wrong - the ICS originally published a piece claiming that the boundary mirrored the collapse of civilizations, but that page was later removed. Maybe it was a case of geologists trying to find a story hook to help for publicity purposes, only to realize not long after that they'd got it completely wrong?

I'm going to look into this a lot more.