I'll insist the Stonehenge bluestones were carried to Salisbury Plain by ice sheets until I'm blue in the face.

Once, the bluestones formed an inner circle within the larger sarsen stones, with others in a "horseshoe" arrangement within that.

Now, as reported in this paper last week, Pembrokeshire-based geologist Dr Brian John also dismisses the theory the bluestones were transported by land and water from the Preseli mountains in west Wales, and suggests ice was the carrier.

But readers of this page will know that I and the archaeologist Aubrey Burl have advocated this idea for years.

In 2006, I reported how Aubrey, an expert on stone circles, in his book Stonehenge: A New History of the World's Greatest Stone Circle, poured scorn on the popular "floating platform" idea that the bluestones were ferried by sea and river.

Certainly, the attempt by the Preseli rural development organisation in 2000 to transport a bluestone by land and sea became farcical when its boat sank. Significantly, Dr John took part in this abortive exercise which ended with a bluestone on the seabed off Milford Haven.

Even Professor Richard Atkinson's success in the 1950s, in moving a stone from the Avon using punts, rollers and haulers, was over only a mile.

It's more realistic to think that, as ice melted after one of the Ice Ages, the bluestones were left handy for the builders of Stonehenge.

Burl draws attention to the "awkward" 1801 discovery, in a long barrow 12 miles from Stonehenge, of a bluestone which was later placed in Salisbury Museum.

Also, the Stonehenge bluestones are not identical. While some could have come from the Preselis, others could have come from Snowdonia.

What geologists should now be looking for is a trail of bluestone rubble on Salisbury Plain, and further afield, which could be traced to its various origins.