The Parallel Roads of Glen Roy


The West of Scotland bears witness to the up and downs of the land and/or the sea.

Rubha an Dùnain or Rubh’ an Dùnain is an uninhabited peninsula to the south of the Cuillin hills on the island of Skye in Scotland.

This headland rises to over 30 metres (98 ft) above sea level.


It had been known for some time that an artificial “Viking canal” had been constructed at some point in the past along the length of the stream that runs from the loch to the sea.

In 2000 Dr David MacFadyen, of Tarskavaig, Skye, exploring the reeded margins of the loch when its level was exceptionally low, recovered an oak boat timber which was subsquently lodged in the Inverness Museum and later radiocarbon dated to c 1100 AD.

The piece can confidently be identified as a bite – the transverse timber which joined the upper midships strakes of a clinker-built boat in the NW European tradition.

Its configuration and dimensions suggest that it was part of a vessel similar in construction and size to the faering (6.1 x 1.38m) found in conjunction with the ship burial of
c. 900 AD from Gokstad in Norway (McGrail, 1974).

Rubh’ an Dùnain – Data Structure Report – Colin Martin – Historic Scotland – 2009

Click to access 161440.pdf

The island of Eigg lies only 27 kilometres away – a 3-hour boat trip under good conditions.

There, on the farm at Laig, the two end pieces of a clinker-built boat were found during drainage operations some time before 1878. They were distinctively Norse, and have been carbon-dated to around 1000 AD.

One was unfinished, and the timbers had evidently been buried for seasoning.

Rubh’ an Dùnain – Skye’s Hidden Heritage – Discover a Lost Settlement
Dr Colin Martin – Morvern Maritime Centre – 2015

Click to access Highway-into-History.pdf


Coastal Command – Dave Cowley and Colin Martin
Current Archaeology – September 2011 –

Click to access CoastalCommand.pdf


The East of Scotland also bears witness to these up and downs of the land and/or the sea.


Kincraig Point is a headland on the south coast of Fife, 2.5 km west of Elie.

It is notable for its geomorphology, demonstrating a series of raised shorelines (shore platforms) cut into the western flank of the headland.

They consist of four raised rock benches cut into the volcanic agglomerate of the headland at approximately 4m, 11 m, 22 m and 24 m O.D. and are veneered with sand and shells (Cullingford and Smith, 1966).

Also present is an intertidal shore platform.

Kincraig Point – J.E. Gordon – 2007
Chapter 15: Fife and Lower Tay
Geological Conservation Review – Volume 6: Quaternary of Scotland,-109,481

Therefore, it’s no surprise that [way back in 1839] the observant Charles Darwin believed the Parallel Roads of Glen Roy were of marine origin.

The parallel roads, shelves, or lines, as they have been indifferently called, are most plainly developed in Glen Roy.

They extend in lines, absolutely horizontal, along the steep grassy sides of the mountains, which are covered with a mantle, unusually thick, of slightly argillaceous alluvium.

They consist of narrow terraces, which, however, are never quite flat like artificial ones, but gently slope towards the valley, with an average breadth of about sixty feet.

There are only four shelves which are plainly marked for any considerable length; the lowest one according to MACCULLOCH is 972 feet above the sea; the next above it is 212 feet higher, and the third, eighty-two above the second, or 1266 above the sea; the fourth occurs only in Glen Gluoy; it is twelve feet higher than the third.

Observations on the Parallel Roads of Glen Roy, and of other parts of Lochaber in Scotland, with an attempt to prove that they are of marine origin
Charles Darwin, Esq., M.A. F.R.S. Sec. G.S.
Philosophical Transactions of the Royal Society 129: 39-81 – Read 7th Feb 1839



Darwin argued the Parallel Roads of Glen Roy are ancient marine beaches etched into buttresses of accumulated matter.



The dark line in the accompanying wood-cut (No. 1.) represents the real profile of a shelf, and is copied from MACCULLOCH.

To this I have added two imaginary lines, of which the broken one gives the supposed original form of the underlying rock.

The formation of the shelf, as may be here seen, is chiefly due to the accumulation of matter in the form of a mound, only very slightly projecting beyond the general slope of the mountain, and partly to the removal or corrosion of the solid rock.

The latter effect, although well marked in some particular spots, cannot generally be distinguished, and the shelves no doubt are chiefly due to the accumulation, and not to the removal of matter.

In this same diagram (1.) the covering of alluvium is represented as thicker some way below the shelf, than at the same distance above it.

I believe this is generally the case, and hence the projection of the shelf is often very obscure; and when two or three occur, one below the other, their outline closely approaches to that represented in wood-cut (2.).

Observations on the Parallel Roads of Glen Roy, and of other parts of Lochaber in Scotland, with an attempt to prove that they are of marine origin
Charles Darwin, Esq., M.A. F.R.S. Sec. G.S.
Philosophical Transactions of the Royal Society 129: 39-81 – Read 7th Feb 1839

Darwin was confident he could demonstrate to the Geological Establishment the validity of his “marine origin” theory whereby a tidal sea “gradually subsided” due to the “rising of the land”.


In concluding this part of my paper I will recapitulate the course of the argument pursued.

1st. It is admitted by every one that the horizontal shelves are ancient beaches.

2nd. I showed that no lake theory could be admitted on account of the overwhelming difficulties in imagining the construction and removal at successive periods of several barriers of immense size, whether placed at the mouths of the separate glens, or at more distant points.

3rd. The alternative that the beaches, if not formed by lakes, must of necessity have been so by channels of the sea, was not advanced, only because it was thought more satisfactory to prove from independent phenomena, that a sheet of water gradually subsiding from the height of the upper shelves to the present level of the sea, occupied for long periods not only the glens of Lochaber, but the greater number, if not all the valleys of this part of Scotland; and that this water must have been the water of the sea.

4th. It was stated (the strongest argument being the ascertained fact of the land rising at the same time in one part and sinking in another,) that in all cases the land is the chief fluctuating element; and, therefore, that the above change of level in Scotland, independently attested by marine remains at considerable heights on both the eastern and western coasts, implies the elevation of the land, and not the subsidence of the surrounding waters.

5th. It was shown that in all such prolonged upward movements it might be predicted, that there would be intervals of rest in the action of the subterranean impulses.

6th. By an hypothetical case, the land was subjected to the above conditions, and its surface was found to be modeled in a manner wholly similar, even in detail, to the structure of the valleys of Lochaber as they now exist.

7th. The true theory being considered thus established, objections to it from the non-extension of the shelves, and from the absence of organic remains at great altitudes, were answered and shown not to be valid.

8th. Many points of detail in the structure of the glens of Lochaber, were shown to be easily explicable on the supposition, that the valleys had been occupied by arms of a sea subject to tides, and which had gradually subsided during the rising of the land.

Having attentively considered these several and independent steps of the argument, the theory of the marine origin of the “parallel roads of Lochaber” appears to me demonstrated.

Observations on the Parallel Roads of Glen Roy, and of other parts of Lochaber in Scotland, with an attempt to prove that they are of marine origin
Charles Darwin, Esq., M.A. F.R.S. Sec. G.S.
Philosophical Transactions of the Royal Society 129: 39-81 – Read 7th Feb 1839

But the Geological Establishment had other ideas.

In the 19th century, the Parallel Roads attracted the attention of many early geologists, including the Reverend William Buckland, James Geikie, Charles Darwin, Charles Babbage, Charles Lyell and Joseph Prestwich.

Darwin’s manuscript agenda, written after he studied MacCulloch’s and Lauder’s papers but before his own visit to Lochaber, proves that he intended to look specifically for evidence that the Roads were indeed sea beaches and that their localised distribution could be “explained away” in terms of differential preservation.

In the field, he duly convinced himself, although he failed to find any marine debris at all, and had to re-interpret Lauder’s overflow cols as “land-straits” and explain them away as mere “coincidences” of level.

He wrote up his work as his first major scientific paper, and gave it – such was its importance to him – not to the Geological but to the Royal Society (1839).

The Parallel Roads of Glen Roy: In The Footsteps of Charles Darwin
A Field Guide by Martin Rudwick – 2010
Geological Society of London – History of Geology Group

Click to access Rudwick_Glen-Roy-field-guide_DCP.pdf


Unsurprisingly, Darwin was just too Catastrophic for the Gradualist Geologists.

Sir Charles Lyell, 1st Baronet, FRS (14 November 1797 – 22 February 1875) was a British lawyer and the foremost geologist of his day.

He is best known as the author of Principles of Geology, which popularized James Hutton’s concepts of uniformitarianism – the idea that the Earth was shaped by the same processes still in operation today.

In the natural sciences, gradualism is the theory which holds that profound change is the cumulative product of slow but continuous processes, often contrasted with catastrophism.

The theory was proposed in 1795 by James Hutton, a Scottish geologist, and was later incorporated into Charles Lyell’s theory of uniformitarianism.

The Gradualist Geologists weren’t uplifted by Darwin’s “rising of the land”.

Neither were they moved by Darwin’s missing “sea shells” materialising in inland “gravel pits”.

In the valleys of the Spean and the Roy, I attentively examined, with the expectation of finding fragments of sea shells, the matter accumulated on the shelves, and more especially the thicker beds of gravel and sand which occur at lower levels; but I could not discover a particle, and the quarrymen assured me they had never observed any.

This may at first be thought a strong objection against the theory of the marine origin of these deposits.

But having been led in consequence of Mr. MURCHISON’S remarkable discovery of recent sea shells in the inland counties of Shropshire and Staffordshire, to examine many gravel pits there, and having observed how frequently it happens, that not the smallest particle can be discovered in vast accumulations of the rudely stratified matter, and that when found, the fragments are generally exceedingly few in number and partially decayed, I feel convinced that their preservation may be considered as a remarkable and not as an ordinary circumstance.

Observations on the Parallel Roads of Glen Roy, and of other parts of Lochaber in Scotland, with an attempt to prove that they are of marine origin
Charles Darwin, Esq., M.A. F.R.S. Sec. G.S.
Philosophical Transactions of the Royal Society 129: 39-81 – Read 7th Feb 1839

The Gradualist Geologists preferred the Glacial Gradualism of Louis Agassiz.


The following year AGASSIZ, while visiting Britain primarily for his research on fossil fish, expounded his sensational “Ice Age” theory in London and Glasgow (in outline it was already well known to British geologists, including Darwin).

He argued that in the final waning phase of this geologically recent “Snowball-Earth” episode there would have been extensive valley glaciers in many upland regions.

Agassiz and Buckland (the latter a new convert to Agassiz’s Ice Age theory) then toured the Highlands and duly found widespread glacial traces (scratched bedrock [striae], moraines, erratic blocks etc).

A brief visit to Lochaber convinced them that the Roads were traces of successive levels of a glacial lake impounded by glaciers, like ones that had been, or would be, produced by analogous extensions of present Alpine glaciers (the actualistic method again, as usual).

This GLACIAL THEORY of the Roads purported to solve both the puzzle of the vanished barriers on the (non-glacial) lake theory – they had left no trace because they had simply melted away – and also the curiously limited extent of the Roads, which was such a puzzle on the marine theory.

The Parallel Roads of Glen Roy: In The Footsteps of Charles Darwin
A Field Guide by Martin Rudwick – 2010
Geological Society of London – History of Geology Group

Click to access Rudwick_Glen-Roy-field-guide_DCP.pdf

Jean Louis Rodolphe Agassiz (1807-1873) was a Swiss-American biologist and geologist recognized as an innovative and prodigious scholar of Earth’s natural history, with later American writings that have received scrutiny because of particular racial themes.

Agassiz made extensive contributions to ichthyological classification (including of extinct species) and to the study of geological history (including to the founding of glaciology), and has become broadly known through study of his thorough regimen of observational data gathering and analysis.


In the ensuring years Darwin was ground down by the Gradualist Glaciologists and eventually “conceded” to the Gradualist Geologists and their Settled Science.

The “Parallel Roads” of Glen Roy are lochterraces that formed along the shorelines of an ancient ice-dammed loch.

Four decades after his 1839 paper and shortly before his death, Darwin conceded that he was incorrect.

However, he had conceded that he was embarrassed by “that confounded paper of mine” as early as 1861, in letters to Thomas Jamieson, quoted by Jamieson (1863; 1892).

The Gradualist Geologists still crow about Darwin’s “Gigantic Blunder”.

Darwin made his “Gigantic Blunder” on his visit in June 1838 by drawing on his recent findings in South America during the Beagle expedition and believing that the shorelines were of marine origin.

But did Darwin blunder when he “conceded” to Peer Pressure?

Could the Gradualist Glaciologists have made another Gigantic Geological Gaffe?



Let’s take a closer look…

Gallery | This entry was posted in Arabian Horizon, British History, Catastrophism, Geology, Glaciology, Heinsohn Horizon, History, Uniformitarianism. Bookmark the permalink.

2 Responses to The Parallel Roads of Glen Roy

  1. thx1138 says:

    I just thought it was the Habit in Scotland to build High Roads and low roads and that the low road was always fastest. 😉

  2. Pingback: Shaping The Saxon Shore | MalagaBay

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.