In the Journal of Archaeological Science (December 2014) there is an article on blades and flints from the Hopewell Culture (Ohio, Missouri, Tennesee) – see http://apps.ohiohistory.org/ohioarchaeology/bladelets-flint-ridge-flint-… … and see also www.dispatch.com/content/stories/science/2014/12/07/01-flint-tool-disapp…
The Hopewell Culture, famous for its monumental architecture (the Ohio mounds) and massive earth moving enterprises, had a wide interaction sphere. In other words, it traded far and wide with contemporary peoples. Copper came from Ontario, mica from the Carolinas, obsidian from Montana, and shells came up river from the Gulf of Mexico, and so on. Why was Hopewell a magnet for trade – what did they make or possess to encourage such wide ranging trade networks? Well, it seems that Hopewell people had a prized item that other people desired – rainbow coloured flint. Tons of flint, it is calculated, were dug out of quarries at what is known as Flint Ridge. Flint knappers then fashioned the flint, in situ, into two standard forms that were traded far and wide. The first format was as small leaf shaped blades that were attached to wooden hafts and used in a variety of ways – for skinning and cleaning hides, for cutting and scaping etc. The second format was as flint cores – roughly cone shaped. These were the equivalent of metal ingots, and transported as cores to be worked into longer blades at the point of destination. These two forms of Ohio flint are found right across eastern N America.
Bladelets were used to work bone, antler and wood – and were extremely versatile tools. You would have thought the use of flint from Ohio would have outlived Hopewell – but it didn't. When Hopewell collapsed the rainbow flint was lost – and the technology to create the leaf shaped flakes and the flint cores with it. The key appears to be the era of Hopewell civilisation, between 100BC and 400AD, coinciding with the Roman Warm Period on the other side of the pond. Its demise occurred at exactly the same time the Roman Empire experienced death throes. These are usually blamed on barbarian invasions – an idea that ignores the fact that something caused the barbarians to shift and migrate. The explanation is that barbarians from further east were pressing up against them – but what caused the eastern barbarians to become restless enough to migrate long distances. It is rather illuminating to see that the same thing was happening in N America at the very same point in time. Environmental change is a factor in the Dark Ages and the inference is that similar environmental change was occurring in the Americas.
In addition, we may note that Hopewell was abandoned in the same way that Maya cities were often abandoned and covered over with earth – taken out of service. The same thing has been noted with the temple complex on the Ness of Brodgar in the Orkneys – but a couple of thousand years prior to the Hopewell abandonment. The similarities lie in the fact that buildings with a religious (for want of a better word) flavour were purposely decommissioned as if the gods had ignored the efforts of the humans. Was all the effort put into the mounds and circles and plazas etc all deemed without purpose – the gods had not listened to humans and it was all to no avail. We may also wonder why Christianity suddenly blossomed around AD400 in Celtic western Europe, had the old gods been seen to have failed? The Roman world fell into disastrous decline for a while and when the dust lifts different people are dictating events and the old imperial system has been modified. Signs and wonders in the sky, and transient phenomena of various kinds, do not leave a mark on history. We don't know what might have been involved – what was happening in the sky in order to drive people to adapt to a new belief system. Writing was not universal – and many of the documents that have survived have been rewritten and reassessed in a different era. Just as modern historians are want to smirk at references to unusual events in the sky, and the idea comets brought death and destruction, so too did people rationalise the abnormal in days long gone. Oh for a mobile phone with camera on the Dark Ages.