For the past 2 or 3 years I’ve been taking an interest in ice ages. In part this has been because it’s seemed to me that our current Holocene warm interglacial is more likely to come to an end soon with a return of ice age conditions, than it is to bring the kind of global warming that many people are so worried about. I’ve even built my own simple global climate model: many years ago as an architectural student I used to build electronic heat flow models.The ice sheets in my model melt at their base, and are replenished by snow on top, waxing and waning in depth and extent.. And this is what is actually happening with the ice sheets on both Greenland and Antarctica. Temperatures beneath the ice rise above freezing point, and streams of water flow from under them.
And the odd thing about this is that in a glaciated world the only places that humans could survive would be in the warren of tunnels beneath the ice. These regions would have been warm, and with a plentiful supply of fresh water. I’ve begun to wonder if there might have been enough sunlight filtering down through transparent ice to even enable plants to be grown in hothouse conditions. But because the ice is always melting, the ice sheets are always slowly descending by a few inches every decade, and so I wondered if the ice needed to be held up to prevent the tunnels beneath them being crushed.
And this led on to the novel idea that megalithic structures – stone circles and avenues and dolmens and menhirs – found all over the world may have had exactly this purpose: to hold up hundreds of metres of overlying ice. That was why they were so big: they had to carry hundreds of thousands of tonnes of ice. This warm underworld would have had chambers with barrel vaults and domes of ice, dimly lit by sunlight filtering down from above, supported by vast stone or ice pillars, with underfloor heating maintaining air at a more or less constant temperature. They would have been like transparent Roman thermae. They would also have been like mediaeval cathedrals or modern steel and glass buildings. To build them rocks would have been slid across the surface of the ice, and then lowered down to the base of the ice sheet through vertical shafts,
This is a quite different method of construction than those imagined today, with thousands of toiling slaves hauling rocks up slopes as they were built upwards. The stones would have been slid across the ice from high mountain quarries many miles away, and lowered on ropes. Relatively few people would have been needed. In the case of Stonehenge, the bluestones come from the Preseli mountains 140 km away in Wales, and the sarsen stones come from the nearby Marlborough downs. In both cases the quarries from which the rocks were transported were several hundred metres above the Stonehenge site. Stonehenge would not have been a temple or an astronomical observatory, but instead an access portal to the underworld beneath on Salisbury plain, much like a London underground station (and with much the same purpose), roughly equidistant from the present south coast of England and the rivers Thames and Severn.
There are some problems with this idea, of course. For a start it is not believed that Stonehenge was buried beneath an ice sheet during the last ice age. Furthermore it is believed that Stonehenge was built only 5000 years or so ago, not over 12,000 years ago during the last ice age. But the extent of glaciation in Britain is not known with exactitude: evidence of glaciation is usually found in the form of moraines or drumlins made up of rocks transported by the slow-moving ice sheets, and deposited on the land surface below when the ice melted. But this would only seem to have happened where the ice was very deep: modern snowfalls, even those that are deep and long-lasting – do not leave such evidence of their presence. An ice sheet only a few hundred metres deep may have left little or no evidence of its existence, particularly if it had lain motionless on a flat plain like Salisbury plain. And if Stonehenge had been constructed by lowering its stones through an ice sheet, there would have been no abundant flora or fauna initially present to allow carbon dating. It would only have been after the ice had melted that plants and animals and modern humans would have gained access to the site: the subglacial underworld would have been swept away in a flood as the ice melted, leaving barely a trace. Stonehnge radiocarbon dating may produce relatively recent dates simply because Stonehenge only emerged from the ice relatively recently.
I’ve never encountered an explanation anything like this for the purpose and construction of the megalithic structures around the world. It relies upon a number of suppositions, the untruth of any of which would serve to negate it, Firstly that the world had much more extensive ice sheets than is presently supposed. Secondly that there were in many places warm environmental conditions beneath the ice. Thirdly that humans were able to live in some of these places, accessing them either by the rivers that flowed out from under the ice sheets, or by vertical shafts through the ice as just described. Fourthly that they were entirely swept away by a global flood at the end of the last ice age, after which humans had to adapt to a completely new environment,
It’s a completely different picture of history. And it’s one which is at odds with the current consensus. But it’s nevertheless a perfectly rational hypothesis. It simply supposes far more extensive glaciation during the last ice age than is presently believed. It does not suppose that the civilisation that built the megaliths was highly advanced: it was a stone age culture that built using stone and ropes and ox-drawn sleds : no aliens or flying machines required.
There’s more that could be added. Was Roman architecture a reflection of a far more ancient ice architecture? Were doric and ionic and corinthian column capitals a recollection of slowly melting ice columns? Were the “clashing rocks” of Homer’s Odyssey icebergs? Was mummification a substitute for the older practice of deep-freezing the dead?
I doubt if this idea will ever catch on, somehow.
I suspect it’s a bit too far out.