When looking at the history of 19th century geology in Scotland, and in particular, at the Highlands Controversy, certain names stand out: Murchison and Geikie, for example, and later, Callaway and Lapworth. Once the official survey in the far north-west was underway, the work was dominated by the legendary pair, Peach and Horne. Such is their fame that you can even meet them now at Knockan Crag, or duplicates anyway! But of course, there was a whole team at work, struggling to unravel the hugely complicated geology of the region in a series of wet summers from 1883 onwards.
Some other names might ring a bell, such as Henry Cadell, who built models that showed how structures might crumple under lateral pressures, and maybe even Charles Clough, whose work, in particular his superb mapping, was of particular merit. But for many of us, most of the surveyors are just names that appear at the bottom of the maps. T.M Skae, for example, who can be seen in this 1868 photograph of the Scottish Survey staff , standing second from the right.
The booklet A History of the Geological Survey in Scotland, published by the Natural Environment Research Council, states that he died in 1889, aged just 42, with an inference that the dreadful weather the Survey team endured was partly responsible. Others suffered too – J.R. Dakyns lost an eye, suffering temporary blindness from exposure, while H. Miller was ill for most of 1889. It was at this time that Edward Greenly joined the team, a name found both on the maps and in the 1907 Memoir published by the Survey, but one of which you may not have heard unless you know of his book, “A Hand Through Time”, which was published in 1938.
The book was issued in two volumes, and is part biography, and part eulogy of his beloved wife, who died in 1927. It is in many ways a very private book. Having written it, Greenly was keen that it should be seen at first only by close friends, with general distribution after his death. In the end, it was published well before his death, which occurred in 1952. The full title gives an indication of the breadth that it covers: “A Hand in Time – Memories, Romantic and Geological; Studies in the Arts and Religion; and the grounds of Confidence in Immortality”. I struggle with some of the romance , not helped by the fact that the love-letters are written in a rather archaic style, even for the 1880s, sprinkled with ‘thees’ and ‘thous’ and ‘thines’, which all becomes a little cloying. The geology, though, is utterly fascinating, for this is a man who worked with all the key players at that time – Geikie, Peach, Horne, Clough, Teall – and who is keen to dwell as much on the interaction of these eminent colleagues as he is on the geology itself. I don’t think a better record exists of what it was like to work on the Geological Survey of the Northern Highlands.
Edward Greenly was born in 1861. His father was a doctor, at first based in Chatham, Kent, then in Bristol. His father had to deal with a number of diseases, and Greenly remembered him spotting an early clue as to how cholera was propagated: there was a street, along which on one side, “hardly a house escaped. Along the other side, there was not a single case. Then it transpired that the two sides drew water from two different wells….” His father was not particularly interested in geology, but knew enough to point out to his young son “the Carboniferous Lias Limestones, the Oolitic Freestone from Bath, the Sandstones and the Granite in all the local building stones.”
He met his future wife, Annie Barnard, in 1875, but it was to be another fourteen years before that friendship developed into an engagement. In the meantime, Greenly learnt how to ride a horse from his uncle Colonel Dowling, tuition which, he found later, ”at a certain stage of the Scottish Survey, …. was of the greatest service.”
He decided to study for the law in 1883, but he realised his calling was geology when on holiday in Wales in 1884. He recalls that on an expedition to Cader Idris, “the weather was extremely hot…and when we reached the mighty crags which look down on Llyn-y-gader, the sun had not risen high. Now the great sheet of micro-granite has a strong columnar jointing, and this is nearly vertical, so the low angle of the rays left dark shadows in the cracks. Thus the structure stared us in the face….That morning it was most impressive, and marvelling what it might mean, we deplored our ignorance out loud.”
With the encouragement of his father, he chucked his ‘Articles’ and started a general science degree at University College, London, where the geology was taught by Professor T.G Bonney.
This is a name many will recognise. His speciality was petrology, the microscopic study of rocks that was a comparatively new branch of the science at that time. Bonney was an important contributor to the discussions concerning the nature of the Logan Rock that so puzzled the geologists during the Highlands Controversy. Greenly found him very formal, a don of the old school, who influenced him “less by what he taught than by his inspiring personality.”
Indeed, he was left to do much of his fieldwork on his own. Basing himself at the house of his father’s cousin, a Miss Westcott, he examined the country around Bristol during the summer of 1887. Miss Westcott herself was interested in Natural History, and remembered all the important people of that time – Murchison, Sedgwick, and the “lank figure of Edward Forbes” whom she watched “striding up and down a platform and acting the movements of a fossil reptile, to the delight of an audience at a British Association”. Forbes was the Survey palaeontologist, and briefly Professor of Natural History at Edinburgh University. Another senior geologist from this time that Greenly remembered was John Judd, who also played his part in the Controversy. He came up with this nugget:
“When one series of strata rests on the upturned edges of another, then the newer series is ‘unconformable ‘ to the older. Well, examination question: ‘When are old rocks said to be unconformable?’ Answer: ‘When they do not conform to the rules laid down by geologists.”
“Geologists have been satirized,” comments Greenly, “but never, surely, with quite such cruelty.”
Greenly tried a bit of mapping around Portishead, completely unaware that the area is full of thrusts and folds. “I never guessed at the time “ he admits, “but this daring bit of mapping was what determined my career.” Whilst doing fieldwork on August 23rd 1887, he found himself on Stapleton Road Junction, where he had to change trains. “Pacing the platform,” Greenly writes,” was a noticeable man with long grey beard, knee-breeches, and a bag upon his back; strong-looking, upright, and with a somewhat nautical expression, such as sailors acquire from the habit of gazing out into the offing. This man got into my train, and said to me at once:- ‘You look as if you have been geologizing.’“ As Greenly had to get out at Montpellier Station, their journey together lasted only some five or six minutes, but the stranger suggested another meeting, and gave Greenly his card. Imagine his delight when he read the name ‘Prof. A.H. Green, The Yorkshire College, Leeds’, for this was the author of his favourite textbook, Physical Geology! They enjoyed three days out together later that week, and then Green invited Greenly up to Yorkshire for another three days during the winter. In fact, these were the only six days in which Greenly had a guide in the field until he joined the Survey. He showed Green the map he had made at Portishead, and on the strength of this, and his general character and enthusiasm, Green put his name forward in February 1888:
“I have written to Dr. Geikie asking whether he will be able to find a post for you on the Survey, and giving him the reasons which I am happy to say are weighty, why I thought you a very fitting man for such a position.”
Nowadays, one might expect the need for a number of definite qualifications if seeking a job in geology, but these were still comparatively early days in the science. A year passed before Greenly was summoned to Jermyn Street, the London headquarters of the Survey. There, to his amazement, Geikie greeted him with the news that there was a vacancy, and he was being offered the position. His having no degree was no hindrance. In their chat, Greenly indicated that he would love to meet Peach and Horne at some point. Geikie replied, with a peculiar smile, “ I think that you will get an introduction to them, for it is to the North-west Highlands, and to Horne, that I am about to send you.”
So it was that in July 1889, Edward Greenly joined the Geological Survey in the far North-west of Scotland. He was 27, and his work earned him 7/- a day, giving an annual income of £127-15s-0d. If he stayed at the job for more than 8 years it would rise by 1/- a day, otherwise the only hope of an increase was to fill a vacancy at a senior grade. Much of his work would involve mapping, the process of which he described in simple terms:
The geologist goes out with an ordnance survey 6” map, armed “with pencils, and with one or two instruments for finding out, and that precisely, where he stands upon the map, since his first duty is to plot the positions and forms of the exposures of rock. Then he ascertains the nature of the rock, but since its outer crust is usually decayed, he may need to detach a fragment, and this is the purpose of his hammer; while, as its texture may be fine, he has a pocket lens as well. With his ‘clinometer’, he measures the inclination of the beds, and with his compass finds their trend. These are his data. From them, combined with the form of the land, he infers the boundaries, and plots them. All is inked-in with a waterproof ink when he gets home in the evening. Later on, a copy is coloured, and this represents the rock-mosaic.”
He emphasises the “heavy toil of the body…when one’s ground is miles away, when it is up 1000 feet, when one spies an exposure of rock in the middle of a bog, or finds that for access to another, one has to wade a narrow gorge.” He also emphasises the military style of the Survey. One did what one was told, was sent to a specific area, never to stray away from it, and in the early days, a uniform was provided.
Quarterly returns had to be sent in, which included the number of square miles surveyed, and also what he calls the “linear mileage of geological boundary”, which I take to mean the miles walked in surveying the area. Greenly confesses that his square mileage was always rather low, from 41 – 63 miles, but his ‘boundary’ ranged from 209 miles to 535, because he was often in very complicated areas. He states he was never hurried by his seniors.
All of the above toil and complexity was especially true in the Highlands. “The research in which I was sent to take a part”, he writes, “was the finest then going-on in the world, if indeed there had ever been a finer!” And with what a team: Peach, Horne and Clough, each one of them, according to Mrs Greenly, who seems always capable of hyperbole, resembling the child of a king. He met Peach first in Edinburgh, the great man giving him “a grasp of welcome, then…a glance up and down and through and through and out the other side”. He then met Horne at Inverness, from where they then proceeded by train to Achnasheen, and thence to Kinlochewe. Time enough for Greenly to assess his other, less demonstrative hero. “I had an immediate instinct that here was a soul that rang true…he was a blend of solemnity and whimsicality, which came out that very day.” Commenting on the darkening skies as they approached Glen Docherty, Horne warned his new colleague, making the most of the rolled Scottish ‘r’, that “the land we’re bound for is a land of r-r-rain and r-r-rheumatism!”
Greenly received his training from Horne on the lower slopes of Ben Eighe, which he describes as “a maze of isoclinal folding cut by a score of minor thrusts.”. In mapping, his tutor particularly emphasised the need for care and scrupulosity. “Not a note, line, or symbol must ever be put on the map which was not drawn on the ground itself.” He was to work steadily, not dashing after some interesting feature that caught his eye, for those details would emerge with time. His first bit of solo work was on the Moine schists of Glen Docherty. They were thought to be uniform, but Peach suggested “one can never tell what may turn up in the Moines.” Horne added “This fellow is desperately keen. Should anything unusual turn up, trust him not to miss it.” And miss it he did not: he found a band in the Moine which was “studded with little lenticular felspars.” His suggestion that this was pebbly grit was met with cries of “impossible, for the Moines are reconstructed Lewisian Gneiss”, that being the view at that time. It took another four years before the sedimentary origin of the Moines was acknowledged, and “Peach and Horne were generous in assigning to the grit of Glen Docherty the honours of pioneer on this most crucial point.”
Archibald Geikie visited the area in the summer of 1889. Greenly does much to defend his boss throughout the book. “Though somewhat chilly in demeanour, he was excellent company” is how he describes him here, and he is struck by Geikie’s “quickness on any new and difficult point, and even more with the beauty of his drawing.” Later, he observed that Geikie “was masterful, he could be a little chilly, and these traits tended to alienate men’s sympathy.” But he adds “he had another side: he could be very kind.” It seems there are many contradictions in the character of this important and complicated man.
In the autumn of 1889, Greenly was sent to Thurso and the Caithness flagstones, which he found a little dull. He also spent some time in London where he was proud to be elected a member of the Geological Society. In April he was back in Thurso, but to his delight, he was later sent again to the North-west where he continued working to the south of Kinlochewe. He became more convinced that the Lewisian Gneiss must be sedimentary, which led to heated discussions between his two seniors.
Greenly writes of the problems involved in ‘joining-up’, which for him began at this time. This was a crucial moment in mapping, when one man’s work had to be lined up with that of the officer on the adjoining area. If all went well, their maps, laid edge to edge would correspond. Inevitably, disputes sometimes arose. One officer reputedly said “If I see trouble brewin’, I just draw a hell of a fault along the whole confounded frontier, and cut off every blessed line.” Another story involved Green, who claimed that so precise had been their work that he actually met Dakyns upon the ground when tracing the same line to their frontier. “H’m, yes,” said one of the listeners slowly.” I happen to know that country well, and I can tell you fellows that the place where Green and Dakyns met was just the only public-house for five miles around.” Such are the guileless stories that colour the solitary life of the 19th century surveyor.
Still, there were visitors to break the monotony. Greenly’s elderly parents made it up to Kinlochewe that summer. A local crofter’s wife dislocated her shoulder, and with the ‘local’ doctor living some 18 miles away, Dr Greenly senior did what was needed there and then. News quickly spread throughout the area that medical assistance was near at hand, and, moreover, dispensed without any charge, and Greenly’s 86-year-old father found himself with a brisk and unexpected ‘practice.’
More significant guests appeared, such as Wilfred Hudleston, who when the Controversy was nearing its conclusion, observed that “Where there was Logan Rock, trouble is sure to ensue.” Greenly thought that he “belonged to a type more frequently seen 50 years ago than it is today, and whose passing I regret: the man of wealth and social standing who does substantial work in science. Tall, stately, courteous, and with a deep yet gentle voice….” Another visitor, who took up a very brief 20 minutes, was Andrew Carnegie, the Scottish/American industrialist, who wanted information on the state of the roads on which his heavy coach-and-four was travelling. “His manner was not ‘military’ “writes, Greenly, “yet written on him as plainly as on the lips of Caesar was the air of a man whose word was law.”
The autumn of 1890 found Greenly in Portskerry, on the north coast of Sutherland, where he was delighted to be back on the crystalline schists of the Highlands. He found quarters at a shop, where he had to get used to a diet of oat-meal, barley-meal, and swedes. One day, his host said that he had to go into Thurso, and would be able to return with some fine turnips. He returned empty- handed: “I couldna’ get ye the neeps. I marked a place as I drove out, but on the way back there was the farmer standin’ in the very middle of the field, so how could I take them?” Clearly, raiding in Scotland had not come to an end. Family prayers in the evening were a ritual accompanied by slow, adagio-like chants that Greenly had never come across before. Peach later informed him that they were picked up on the Continent by Highlanders fighting in the Catholic armies of the Thirty Years War. The Highlands then was predominantly a Catholic area: the soldiers from the Lowlands fought with the Protestant armies, and adopted Protestant customs and music.
As regards the geology of the area, the psammitic schist (i.e. derived from sandstones) gave Greenly a clear picture of the granitoid permeation that prevailed, in a way that was not the case at Kinbrace, where he found himself a year or two later. There, the schists are derived from mudstones, “and so intimate is the permeation that it is often hard to tell where sediment ends and granite begins.” Today these rocks are referred to as migmatite, and they represent an extreme stage of metamorphism where the rock has started to melt. The melt has been kept in small pockets and veins, close to where it was formed and never escaped, so that as the schist cooled the granitic melt then crystallised where it formed, in intricate pockets and veins within the schist.
In October, he heard that Horne was to be joined by Jethro Teall, and they would be exploring the Tongue/Eriboll country. Greenly could not resist the chance to explore the region with the very man who was one of the first discoverers of the thrust planes. He wrote to the Director asking for permission to ‘leave his station’. He received no reply, and so had to take his own decision to go, for which he was later reprimanded, but only verbally.
The weather was atrocious, but they were able to do a certain amount of exploring. At one point, Teall went off by himself, leaving Horne and Greenly to visit the Arnaboll thrust. The ferry boat journey across the Kyle of Tongue was exciting, to say the least, some passengers doubtful that they would make it to the other side.
At the thrust, Horne had to shout his explanation, and at one point, he was lifted up into the air by the force of the wind. Undaunted, Horne beckoned “and now, for Creag-na-faolinn”, and off they went down to the bottom of Loch Eriboll. They clambered all over this cliff well-known to geologists, on all fours, for standing was impossible. “Oh, those wild and whirling days!” writes Greenly. “How many geologists have had experiences such as those, at once of heaven and of earth?”
By this time, he was back in touch with Annie Barnard, and they became engaged in January, 1891. But in April of that year, Greenly returned to the north, and after starting at Strathnaver, he was sent to Kinlochewe, and the steep slopes of Slioch. Access was often going to be difficult, his ground being four or five miles from Kinlochewe. There were rivers to be crossed which would be impossible when in spate, so he obtained quarters on site, in a remote shepherd’s house called Smiorasair, which is marked on this first edition OS map.
His belongings had to be shipped over Loch Maree, and carried up the tiny track that led up the 400 foot crag on which the cottage sat. “To arrive at Smiorasair was to step back centuries”, he writes. “The shepherd (an auburn bearded giant) and his kindly wife were true and simple children of the ancient Highlands, and their cottage had a thatched roof, and earthen floor.” This latter was so rutted that Greenly had to wedge his table up on stones, to steady it for his intricate mapping work. Contact with the outside world was tricky, but the children, who came home twice a week were able to act as postmen, there being of course no regular service there. The shepherd cut his own peat for fuel, and the ploughing of his potato patch was done by ‘cas crom’, that strange, twisted device that was used widely in the Highlands well into the 20th century. “Was it not a paradox,” suggests Greenly “that I should have worked at Smiorasair with precise modern maps, and yet have ploughed with the cas crom?”
And what work he had to do on Slioch.
This is the Geological Survey map which was published in 1913, showing the intricate detail of the mapping needed on the hillside of Slioch.
“The lines are so crowded” he writes, “that one had to crawl up and down the mountain side, fixing one’s position every few yards. On June 15th he wrote to his wife that he had “long puzzled over the hill-side.” He thought he would have to seek Clough’s help on the problem, but then continues “I sat down to lunch on a point that commanded the situation. Suddenly came an inspiration, I saw the whole thing in a flash. I drew section after section, then spent the afternoon scrambling up and down, and found everything fit in.” These structures can be found in the 1907 Survey Highland Memoir, accompanied by this figure 10.
They were indeed important structures, still not fully understood when the memoir was published. Greenly describes a gathering held on the ground with Peach, Horne, Clough, Teall and Macconochie:
“Talk about fights; you should have seen us out on the side of a mountain yesterday, I contending against Peach with all my might, and Teall egging us on…Well, I took one view of the ground, Peach took another, and he is the most formidable opponent I know, for his resource is endless, and so quick. However, we ended each of the same opinion still, after much shouting.”
Soon after this event, orders arrived that they were to move on to the virtually untrodden wilderness between Loch Broom and Loch Maree. It was to yield yet more significant information regarding the age of the rocks in the north-west. At Dundonnell Inn, they were told there was a track leading over the pass to Strath-na-sheallag, where Peach and Horne were to be based. The track, though was just a jumble of stones. Greenly was sent on a further three miles to a lodge called Larachantivore, which could be found at the foot of Ben Dearg-Mhor. Greenly thought it the most remote quarters of all he occupied in his spell in the north-west.
The rivers proved to be serious obstacles in the region. The few local visitors who used the glens often used stilts to cross them, but Greenly, after one or two humiliations realised this was a skill he was not going to master. The higher ground was all sandstone, the lower, gneiss which was laborious to survey, being full of basic dykes which were hard to define against the older black masses which were of a similar colour. What is more, the dykes ran across the contours, so he was constantly following them up and down, sometimes over a distance in height of 1,000 feet. Each dyke might also branch, so what had been one dyke at the top was three by the time he got to the bottom.
One morning, a note from Horne arrived, announcing his important discovery: “I have found fragments of a trilobite in the calcareous shales. Come and see them.” They turned out to be the first Scottish Olenellus, which dated the sedimentary layers Cambrian, and the sandstone pre-Cambrian. Gone was Murchison’s Silurian territory in this part of the world.
Greenly and Peach had scoured Glen Logan for fossils in similar beds, without any success. Then Peach reminded Greenly of the sedimentary grit he had found on his very first solo surveying at Glen Docherty. Peach predicted that there would be better ones there, and there were, the finest examples of them all. Greenly was dismayed – how had he missed them? It was his one great disappointment. But he was back to the gneiss at Bein Dearg-Mhor, which now took on an even more exciting aspect. If the sandstone was Pre-Cambrian, what age was the gneiss? He searched diligently for fossils that he hoped would give some indication of the rock’s age, but found none. It is recognised now that most of the Lewisian Gneiss was metamorphosed igneous rock and would never have had fossils. Even the parts that were sedimentary are greatly altered by metamorphism, which would have destroyed any fossils even if there had been any.
The Moine, as Greenly proposed, was originally of sedimentary origin and although ancient there would have been some life at the time. Some of the Moine has been strongly metamorphosed and deformed and that would have destroyed any fossil evidence, but other parts are not greatly altered and have the potential to preserve some. Greenly was disappointed by his own efforts, but in the 100 years that have elapsed since that time, no fossils have been found.
If they needed to travel any distance, they used the local ponies. Peach’s choice was a dusky creature known as ‘Smoker’ which had dim stripes that made him think he was riding on a zebra. On one occasion, he could be found “riding down the glen, and holding up to his forehead a pair of antlers in the character of Herne the Hunter.” Greenly’s pony was the best of the bunch, so much so that when Geikie came to visit the site, Greenly had to hand his beast over to his boss, and he found himself on something much less reliable. “He tried to kick, he tried to rear, he jibbed, he tried every device to get rid of me…and we pursued a somewhat zig-zag course for some distance, beyond which I knew there was a mile of smooth alluvial turf. ‘Now, go ahead if you like’ said I. And ahead he did go, never had I had such a thundering gallop. Then came the river, and through it he went with a cloud of spray. But after that he struck to his colours, and behaved quite like a gentleman.” So those hours spent riding at his uncle’s 12 years earlier bore fruit eventually.
Greenly recounts another experience with the local wildlife, this time on the summit of Bein Dearg-Mhor. For a change it was a very hot day. “By degrees I must have fallen asleep: for how long, I do not know; but awoke with an uncanny feeling that here, on one of the most solitary spots in the British Isles, I was somehow not alone. And indeed I was not, for who was there, scarcely a yard from my own shoulder, but a great golden eagle. Still and silent I lay: silent, majestic he sat, long enough for me to feast my eyes on him at my leisure. Then something…seemed to arouse his suspicion. He took a little run, spread his mighty wings, and launching himself out over the cliff edge, soared grandly round and round, till he disappeared behind the crags. An eagle within a yard, yet wild and in his native haunts: it was an experience for a life-time.”
On August 3rd 1891, he left Strath-na-sheallag, to return south for his wedding. The journey over the pass was accomplished on his original, faithful pony, which having given no trouble at all when out in the wilds of Bein Dearg-Mhor, suddenly became nervous when on the road proper at Dundonnell. “Nervous like a savage is when suddenly brought into civilisation” as Greenly put it. Later that summer he returned to the Highlands with his new wife, first back to Strathy Point, then to Kinbrace near Helmsdale towards the east coast. The geology lacked the drama of that in the west, but it had to be surveyed.
Greenly eventually resigned from the Scottish Survey in 1895. He summed up his work there in one paragraph:
“Totally unknown, without so much as a degree, I was sent at once to the north-west Highlands, where I learnt how to detect and how to estimate a thrust-plane. I mapped many miles of the Moines, and almost every facies of the Lewisian Gneiss. Even my failure to find Olenellus taught me never to leave a dark shale unsearched. The Caithness, which I did not love, taught me at least about Glacial deflection. Finally, in Eastern Sutherland, I became at home in every grade of metamorphism, from rocks with surviving sedimentary grains, up to granitoid permeation.”
Perfect training, he thought, for Anglesey, for that is where the happy couple next chose to base themselves, and his survey of the geology of Anglesey was completed by 1919. And there we should leave him, except he added two fascinating chapters in the second volume of his book which we cannot ignore.
The first comprises a series of character sketches on a select few of his colleagues, notably Peach and Horne. That these two are so often mentioned as a pair is a testament to both the friendship, and the working relationship that they enjoyed for over 60 years. Greenly states that “excepting Peach’s Palaeontology, all their work was done in concert, and the several parts they played are indistinguishable.” For this reason they were awarded the Geological Society’s Wollaston medal as ‘Peach and Horne.’
Greenly had plenty of occasions to view them in action. Horne was the steadier of the two, often cautiously holding back when his opinions differed from those about him. Peach, on the other hand would happily wade into any debate, often thinking on his feet, and shifting his position as he spouted. This would annoy Horne hugely, exclaiming on one occasion “Why; hardly ten minutes ago, you said something quite different. Man; I never knew a fellow that could double his coat-tails under him and pop round a corner with the agility you can.” It was the speed of thinking that impressed Peach’s colleagues so. Horne might be first by instinct to a solution to a particular problem, but once Peach had spotted that it was correct, he would speed away with the wider implications, leaving others exhausted far behind. His voice would reflect this quality. “In ordinary conversation, it was deep and very soft. But if excited by discussion, it would grow louder and louder and louder, pitch rising too, till he was shouting and well-nigh screaming.” Greenly went to visit Peach in his last days. His wife was reluctant to allow Greenly access, but she did so on the condition that they did not discuss geology. “I kept my promise”, writes Greenly, “but in vain. For Peach burst out in a torrent: Lewisian, Torridonian, Moines and Dalradian; succession, unconformity, tectonics, metamorphism: point after point about the Highlands. I made no attempt to stop him, in fact I think it did him good. Presently the lady put her head in at the door. I rose, and Peach took my hand, but he hardly said goodbye. Some new idea struck him, and he was shouting geology as I went down the stairs! Such were my last experiences of Benjamin Peach.”
Horne’s appointment in 1901 as Director of the Scottish branch of the Geological Survey might have coloured their friendship, but in fact did not. Peach, as the senior of the two, was offered the position, but he stepped aside for Horne, knowing that his steadiness and administrative ability were far more suited to the appointment. The pair were supposed to write a book together on Scottish geology. What was written was eventually published as “Chapters on the Geology of Scotland” (1930), but for Greenly it was a tragedy that the whole was never completed, mainly because Horne was reluctant to publish without complete agreement between the two of them on any given subject.
Greenly was very keen to show Horne’s perceptiveness, a characteristic which is demonstrated in the other chapter of interest where he discusses what he calls the “two crises in the history of (Scottish) geology.” He was also keen to defend Geikie and Murchison, who received in his opinion too much criticism for their role in 19th century Scottish geology. So, when discussing the first crisis, that of the Southern Uplands, in which the conclusions of the official survey regarding the structure of these hills were shown by Lapworth in the 1870s to be completely wrong, Geikie is often presented as being against any sort of revision of the area by the Survey. The implication was that he wanted to hush the whole thing up. The revision did not take place for eleven years, but Greenly states categorically that Geikie was all for an immediate revision. However, there was no agreement among the leading figures involved in the matter, and it was shelved until Horne and Peach pressed hard for the reassessment in 1888.
Geikie, along with Murchison, is also defended by Greenly in his study of the second crisis, the North-west Highlands and the Survey. In doing so, he reveals exactly how Peach and Horne unravelled the questions concerning the succession of the rocks, which is, I believe, of particular interest. First, though, Murchison and Geikie: Murchison was of course wrong in his belief in an upward succession, while Nicol was correct in urging that the boundary of the Moines must be a dislocation. However, there were other aspects in which Nicol was wrong.
Greenly argues that Murchison’s sections, which show the boundary as a plane of gentle inclination, are very much nearer to what can be seen. Nicol’s sections show the boundary as nearly vertical. In a nutshell, “Nicol was more nearly right as to the interpretation, but Murchison was nearer to the phenomena themselves.” Greenly goes on to suggest that it was quite reasonable for Geikie to stand by his predecessor’s model, even as late as 1883. The two clearly exposed sections at Sangomore and at Knockan did look conformable – even Peach thought that until Loch Eriboll had been fully surveyed. And, in Greenly’s eyes, who blames Geikie for sticking by the theory of the man who had engineered his rapid rise up through the geological hierarchy?
Horne and Peach told Greenly that while they did meet Lapworth briefly in a house at that time, he did not reveal any of his findings to them. On the other hand, there was published material available for them to study. Callaway’s papers had been issued from 1882, and Lapworth’s highly important Secret of the Highlands articles appeared in the Geological Magazine during 1883. Interestingly, Greenly thought that Figure 7 in Callaway’s 1883 paper would have been the most useful diagram relating to thrusting at this stage of the enquiry, 1884.
Peach and Horne were sent to Durness in the spring of 1883. They were instructed to stay to the west of Loch Eriboll, confining their mapping to the Durness basin as far west as Cape Wrath. In Durness they found that they could divide the limestone into seven, and the quartzite into six zones. With the fucoid beds, and the serpulite grit, that gave them fifteen zones in the sedimentary layers. At Sangomore, where the Moine-schists lie with deceptive conformity on the limestones, Peach was convinced: “Why,” he said. “Here is perfect conformity: this is the upward succession of Murchison.” Horne was not convinced, thinking it a local phenomenon. “When we follow this junction further, may we not find the beds truncated?”
Before leaving Sutherland that year they decided to ignore the “never-leave-your-station” injunction of the Survey, and visit the area to the east of Loch Eriboll. It was to be a seminal moment in the history of the Controversy. On Ben Arnaboll, they found gneiss resting on basal quartzite, but to their surprise, this quartzite was resting on fucoid beds! They agreed that there must be movement, on a great scale, and at a low angle. Going further east, they were equally surprised to find no evidence of any sedimentary layers at all.
When Geikie came up at the end of the season, he took them to Sangomore, where they all agreed it looked as if there was a conformable sequence. So encouraged was Geikie that he talked there and then of sending an article to Nature Magazine, asserting that the Murchison model had been proved correct. It was at this point that Horne firmly suggested caution, pointing out that at Eriboll, the succession was not to be seen. “On the contrary” he said, “there are abundant signs of powerful movement. I have the strongest objections: in fact, I cannot possibly assent to the publication of such a note.” Here was Geikie, the man who “to say the least, did not invite opposition from the members of his staff” being strongly challenged by one of his employees, and lo! he heeded his words, and gave way. They went to Arnaboll, where Geikie agreed there was no succession. They then travelled south to Knockan Crag, where again, Peach thought he saw real stratigraphical succession. Horne remained unconvinced. Further south still, near Ullapool, they saw ‘grits’ lying on undisturbed sedimentary layers, but with quartzite, gneiss, and the Moines above. They then crossed Loch Broom where they found more undisturbed sedimentary layers, with strips of gneiss above, then patches of grit and conglomerate, and finally the Moines. There was even an upper quartzite (much beloved of Murchison’s theory) caused as the Survey eventually revealed by a peculiar anticline, as seen in figure 45 in the Memoir.
Winter gave the opportunity for long discussions about the whole issue. Peach still did not reject a smooth upwards succession, but Horne was convinced that the evidence for massive movement was irrefutable. He pointed out that while it looked as if the Moines rested conformably on the limestone at Sangomore, the thickness of the limestone was no less than 1500 feet, whereas at Knockan the thickness of the limestone was only a few feet. Further south the Moines were resting on serpulite grits, in other places on the fucoid beds, while at Ullapool they were resting directly on Lewisian gneiss. East of Ben Arnaboll, they could find no sedimentary layers at all! He continued: “Such relationships must mean either movement or unconformity. But unconformity is incredible, because none of the features characteristic of such a junction are ever to be seen. Where is there any basal conglomerate or grit? The base of the Moines is always platy, silaceous and compact. On the other hand, have we not seen abundant signs of movement in Eriboll, and at a low angle? Depend upon it the base of the Moines is a plane of movement. But it cannot be merely folding: in view of these transgressions, it must be a rupture, and if so, at an astonishingly low angle.”
“Thus,” adds Greenly, “Horne was already far in advance of his contemporaries.”
At the start of the 1884 season, they went straight to Eriboll. Peach went to the shore of Eriboll, the stretch to the north of Heilem, where he almost immediately found a tract of clearly exposed limestone, serpulite grit, and fucoid beds, repeated over and over by minor thrusting. Horne records that “he came home shouting with delight, and with a face like a man who has had a vision of the unseen. ‘This,’ he cried, ‘is piling-up in advance of the great thrust which we have seen on Arnaboll.’ ” Given the obvious complexity of the area they took the unusual step of mapping Eriboll together. On the Arnaboll thrust-plane, they saw the sedimentary layers, piled up with minor thrusting, and the gneiss on top. They noticed it was mylonized, and that the pipes had been deflected and driven to the west. Seizing on a particularly calm day, they took to the sea, and studied the huge cliffs of Whiten Head where they saw the Moine thrust itself, in dip-section with mylonite at the base.
Where Horne had been ahead of his colleague in realising that there was no simple succession, it was at this point that, in Horne’s words “Peach bounded ahead.” He realised that the junction at Sangomore was simply the Moine thrust repeated by a strike fault, that at Faraid Head the Moines were brought down by a dip-fault, and that at one time, the Moines had been brought over the entire Durness basin on the thrust-plane. This thrust plane must have involved at least ten miles of movement. Movement of such enormous force was completely new to British geology.
Greenly gives credit to Geikie for the speed with which he accepted the facts as they were now presented. “These things must be frankly acknowledged,” he said, “and that without delay.” The announcement was made in Nature magazine on November 13th, 1884. It was Geikie who invented the term ‘thrust-plane.’
Greenly is at pains to emphasise the contribution of Horne, how he resisted Geikie’s instinct to publish confirmation of Murchison’s model based on Sangomore, and how he realised that something remarkable was to be found in the Eriboll district, when no one else sensed it at all. The account gives a very clear picture of how well Peach and Horne worked together as a team, and Greenly’s record of the unfolding of the solution is, I believe, of great importance. Indeed, his book, “A Hand Through Time”, is full of fascinating detail regarding the work of the Survey, and I would urge anyone with slightest interest in these matters to read it. While it contains a wide range of subjects – art, religion, feminism, and of course romance – that may not always hold the attention, the value of the geological detail stands out clearly.
This article was written by Alastair Mitchell who has studied the history of geology in the north west highlands and has collected a large number of texts, drawings and photographs relating to the early geologists and the Geological Survey.