Sir Roderick Impey Murchison
Murchison, Roderick Impey
MURCHISON, RODERICK IMPEY
(b. Tarradale, Ross and Cromarty, Scotland, 19 February 1792; d. London, England, 22 October 1871)
Murchison was born into a long-established family of Highland landowners. His father, Kenneth Murchison, died when the boy was only four; and after his childhood he never lived in Scotland. He was educated at the military college at Great Marlow and in 1808 saw active service briefly in the Peninsular War. In 1815 he married Charlotte Hugonin and soon afterward resigned his commission. From 1816 to 1818 Murchison traveled in Italy and under his wife’s influence showed signs of artistic interests, but on his return he sold his family estate and for several years devoted himself chiefly to fox hunting. A chance acquaintance with Humphry Davy turned his attention toward science, however, and in 1824 he settled in London and attended lectures at the Royal Institution. Encouraged by his wife, Murchison soon focused his interests on geology, chiefly through the influence of William Buckland; he was elected a fellow of the Geological Society of London in 1825 and of the Royal Society in 1826. With the advantages of a private income, he was able thereafter to devote himself entirely to science.
Taking as a model the stratigraphical handbook of W. D. Conybeare and W. Phillips (1822), Murchison began the long series of geological studies which brought him worldwide fame and recognition. Almost every summer, for over twenty years, he undertook long and often arduous journeys in search of new successions of strata which would help to bring order to the reconstruction of the history of the earth. He entered geology during the first great period of stratigraphical research, and stratigraphy remained his chief area of interest. He was not a theoretician and generally delegated the paleontological parts of his work to others, but he was an excellent observer with a flair for grasping the major features of an area from a few rapid traverses.
Some of his earliest work convinced Murchison of the superiority of fossils over lithology as criteria of geological age: in 1826 he showed that the fauna and flora of the isolated coalfield of Brora in northeastern Scotland indicated it to be of the same age as the English Oolites (that is, Jurassic), although the rock types resembled the Coal Measures (that is, Carboniferous). In 1828 he accompanied Charles Lyell through the celebrated volcanic districts of the Massif Central into northern Italy, and their joint papers suggest that Murchison was at this time much influenced by Lyell’s theoretical views. His subsequent work in the Alpine region, some of it in the company of Adam Sedgwick, included an attempt to show the continuity of the Secondary and Tertiary strata; but, at the same time, firsthand experience of the vast scale of folding and faulting in the Alps led Murchison toward an increasing catastrophist emphasis on the role of occasional episodes of drastic disturbance in the crust of the earth.
During these first years of research Murchison’s travels brought him into contact with most of the leading geologists on the Continent, and his position as secretary (from 1827) of the Geological Society made him equally well known in Britain. In 1831 he was elected president of the Geological Society (he held office until 1833, and again from 1841 to 1843), and in the same year began his most important research.
At this time the major features of the stratigraphical succession had been clarified down to the Old Red Sandstone underlying the Carboniferous rocks, but below that was what Murchison called “interminable grauwacke"—rocks containing few fossils, in which no uniform sequence had been detected. It was widely doubted whether the method of correlation by fossils would even be applicable to these ancient Transition strata, yet in them—if anywhere—lay the possibility of finding evidence for the origin of life itself. Acting on a hint of Buckland’s, Murchison was fortunate to find in the Welsh borderland an area in which there was a conformable sequence downward from the Old Red Sandstone into Transition strata with abundant fossils. He gave a preliminary report of his work at the first meeting (1831) of the British Association for the Advancement of Science; and in 1835, after further fieldwork, he named the strata Silurian after the Silures, a Romano-British tribe that had lived in the region.
The Silurian constituted a major system of strata with a highly distinctive fauna, notable for an abun- dance of invertebrates and for the complete absence, except in the youngest strata, of any remains of vertebrates or land plants. It thus seemed to Murchison to mark a major period in the progressive history of life on earth. Even before he had completed his great monographic account The Silurian System (1839), its validity had been rapidly recognized by geologists in many other parts of the world. The striking uniformity of the Silurian fauna, in contrast with the highly differentiated faunal provinces of the present day, was taken by Murchison to underline the limitations of Lyell’s uniformitarian approach, and was attributed by him to the greater climatic uniformity of the globe in Silurian times, a result of the greater influence of conducted heat from the still incandescent interior of the earth.
Murchison was well aware of the vast economic implications of his delineation of a Silurian system. If the Silurian period had truly predated the estab- lishment of terrestrial vegetation, the recognition of Silurian fossils in any part of the world would reliably indicate a base line beneath which it was pointless to search for coal: this would save much useless expenditure and also help to assess more accurately the possible reserves of undiscovered coal. A report by Henry de la Beche of coal plants in the “grauwacke”of Devonshire (1834) therefore seemed to Murchison to be a very serious anomaly, and he devoted several years to an attempt to explain it away. He and Sedgwick discovered first that the fossil plants were in fact in strata of Coal Measure age overlying the true “grauwacke”; and later, in 1839, following a suggestion of William Lonsdale’s, they concluded that even these older strata were not pre-Silurian, as they had originally thought, but were the lateral equivalents of the Old Red Sandstone. This definition of a Devonian system was at first criticized as being based purely on paleontological criteria and not on any plain evidence of superposition; but Murchison and Sedgwick soon showed that the distinctive Devonian invertebrate fauna occurred in Westphalia in the expected position immediately below the Carboniferous strata. The following year (1840) Murchison resolved the matter by discovering in European Russia a sequence of undisturbed strata in which the Devonian was clearly underlain by Silurian and overlain by Carboniferous, and in which Devonian invertebrates were interbedded with Old Red Sandstone fish. This established the temporal equivalence of the Devonian and Old Red Sandstone despite their contrasting lithology and fauna.
A second expedition to Russia in 1841 took Murchison as far as the Urals and confirmed this Paleozoic sequence. At the same time it showed him how undisturbed and unaltered sediments could change their appearance radically when traced laterally into a region of mountain-building, and this convinced him of the validity of Lyell’s hypothesis of meta- morphism. He also found a vast development of Paleozoic strata overlying the Carboniferous and named them Permian after the Perm region near the Urals.
In 1839 Murchison’s financial position had greatly improved, and he had moved into a grander house, which thereafter became a fashionable salon of the London intelligentsia. His enhanced social position, coupled with the many distinctions conferred on him for his work in Russia, unfortunately made him increasingly conscious of social prestige and increasingly arrogant and intolerant of opposition in scientific matters.
Murchison’s capacity for transforming scientific controversies into paramilitary “campaigns” against opponents had already been evident in his treatment of de la Beche over the Devonian problem. It was now shown much more seriously in his controversy with Sedgwick over the base of the Silurian. In the same year that Murchison had first investigated the Transition strata, Sedgwick had begun to unravel still older strata in Wales; and when Murchison first established the Silurian, Sedgwick had suggested the name Cambrian system (after the Latin name for Wales) for the older rocks. During their only joint fieldwork in Wales (in 1834) Murchison had assured Sedgwick that the latter’s Upper Cambrian lay below his own Lower Silurian strata, although, as expected, there was a faunal gradation between the two. But when Murchison later realized that the fossils of the Upper Cambrian Bala series were indistinguishable from his own Lower Silurian Caradoc series, he boldly proclaimed their identity and annexed the Upper Cambrian into his Silurian system.
Sedgwick protested that the Cambrian had been clearly defined by reference to an undisputed succession of strata in northern Wales and that it was wrong to alter the meaning of the term just because its upper part contained Silurian fossils. But Murchison continued to annex more and more of the Cambrian into his Lower Silurian, until the two terms were virtually synonymous. Sedgwick claimed that this unjustified annexation was designed to cover two major mistakes of Murchison’s. He had misinterpreted the Lower Silurian succession in its type area and had therefore believed that these strata were younger than the Upper Cambrian when in fact they were of the same age; and—an even more serious mistake—he had wrongly incorporated some Upper Silurian strata (May Hill sandstone) into the Lower Silurian Caradoc series, despite their very different faunas, thus giving the Silurian fauna a spurious uniformity down into Sedgwick’s Cambrian.
But there was even more to the controversy than technical mistakes and a priority dispute over stratigraphical nomenclature. Each geologist, as a firm believer in a progressionist interpretation of the fossil record, ardently desired the distinction of showing that his own system contained the evidence for the origin of life on earth. Thus, when Murchison wrote his Geology of Russia (1845), he asserted that the “unequivocal base—line of palaeozoic existence” was to be seen in the Lower Silurian strata, within which there was a “gradual decrement and disappearance of fossils” toward the base. Furthermore, in Scandinavia (where he had traveled in 1844) these strata were immediately underlain by “Azoic” crystalline schists, in which Murchison believed that it was “hopeless to expect” to find fossils. This was not because they had been metamorphosed (although he agreed that they resembled the metamorphic rocks of later periods) but because they had been formed under conditions too hot to support life. He therefore argued, against Lyell, that geology provided “undeniable proofs of a beginning” to life on earth. His desire to have sole credit for providing these “proofs” is shown by his obstinate insistence that the Silurian fauna was the earliest. Thus when Joachim Barrande first described a distinctive “primordial” fauna (the Cambrian of modern geology) below the previously known Lower Silurian faunas, Murchison did not allow it as a possible paleontological basis for Sedgwick’s Cambrian but incorporated it too into his Silurian.
In 1846 Murchison was knighted and served as president of the British Association for the Advancement of Science; and in 1849 his work was recognized by the award of the Royal Society’s Copley Medal. He later published an updated and more popular version of his work as Siluria (1854), expressly in order to deliver a “knock-down blow” (the aggressive metaphor is characteristic) to those, like Lyell, who still denied the reality of organic progres- sion. The book also contained an assessment of the world’s probable resources of gold, designed to reassure those who feared that the recent Australian gold rush presaged a slump in that metal’s monetary value. In 1855 he succeeded de la Beche as director general of the Geological Survey of Great Britain (thus becoming a professional scientist for the first time), and in 1856 he was appointed to a royal commission to report on the nation’s coal reserves.
From the 1840’s Murchison became increasingly rigid and intolerant of scientific innovation. He opposed the glacial theory of Louis Agassiz and continued to assert that icebergs alone had been responsible for the transport of erratic blocks (“drift”) long after most other geologists had accepted at least a modified glacialism: under his influence the Geological Survey’s maps long continued to use the term “drift” for glacial and postglacial deposits. Murchison’s last major fieldwork, in 1858–1860, was devoted to arguing that the Moine schists of the northwestern Highlands were Silurian sediments, although he had always favored relatively catastrophist interpretations of mountain tectonics and had been convinced a decade earlier of the reality of large-scale thrusting in the Alps. He was totally opposed to Darwin’s evolutionary theory.
Murchison retired temporarily from the council of the Geological Society in 1863 and was therefore eligible to be awarded the Wollaston Medal the following year. He was created a baronet in 1866. He had earlier been one of the founders of the Royal Geographical Society and was for many years its president. Indeed, despite his post with the Geological Survey, he was better known as a geographer than as a geologist in his later years, being prominent in the support of David Livingstone’s and other expeditions. The Murchison Falls of the Nile in Uganda are named after him.
The following are the more important of Murchison’s published works: “On the Coal-Field of Brora in Suther- landshire, and on Some Other Stratified Deposits in the North of Scotland,” in Transactions of the Geological Society of London, 2nd ser., 2 , pt. 2 (1829) 293–326; “A Sketch of the Structure of the Eastern Alps …,”ibid., 3 , pt. 2 (1832), 301–420, written with Adam Sedgwick; The Silurian System, Founded on Geological Researches in the Counties of Salop, Hereford, Radnor, Montgomery, Caermarthen, Brecon, Pembroke, Monmouth, Gloucester, Worcester, and Stafford; With Descriptions of the Coal- Fields and Overlying Formations (London, 1839); “Classi- fication of the Older Rocks of Devonshire and Cornwall,” in Philosophical Magazine, 14 (1839), 242–260, written with Adam Sedgwick; “On the Classilication and Distribution of the Older or Palaeozoic Rocks of the North of Germany and of Belgium, as Compared With Formations of the Same Age in the British Isle,” in Transactions of the Geological Society of London, 2nd ser., 6 , pt. 2 (1842), 221–302, written with Adam Sedgwick; and The Geology of Russia in Europe and the Ural Mountains, 2 vols. (London-Paris, 1845), written with Édouard de Verneuil and Alexander von Keyserling—Murchison wrote the stratigraphy in vol. I.
See also “On the Palaeozoic Deposits of Scandinavia and the Baltic Provinces of Russia, and Their Relations to Azoic or More Ancient Crystalline Rocks; With an Account of Some Great Features of Dislocation and Metamorphism Along Their Northern Frontiers,” in Quarterly Journal of the Geological Society of London, 1 (1845), 467–494; “On the Meaning Originally Attached to the Term ‘Cambrian System,’ and on the Evidences Since Obtained of Its Being Geologically Synonymous With the Previously Established Term “Lower Silurian,’”ibid., 3 (1847), 165–179; “On the Geological Structure of the Alps, Apennines and Carpathians, More Especially to Prove a Transition From Secondary to Tertiary Rocks, and the Development of Eocene Deposits in Southern Europe,”ibid., 5 (1849), 157–312; Siluria. The History of the Oldest Known Rocks Containing Organic Remains, With a Brief Sketch of the Distribution of Gold Over the Earth (London, 1854); and “On the Succession of the Older Rocks in the Northernmost Counties of Scotland; With Some Observa- tions im the Orkney and Shetland Islands,” in Quarterly Journal of the Geological Society of London, 15 (1859), 353–418.
Murchison’s field notebooks and a collection of his scientific correspondence are in the library of the Geological Society of London. Material in the Institute of Geological Sciences, London (formerly Geological Survey), is de- scribed by John C. Thackray, “Essential Source-Material of Roderick Murchison,” in Journal of the Society for the Bibilography of Natural History, 6 , pt. 3 (1972), 162–170.
Some excerpts from Murchison’s journals and letters are published in the only full-length biography, Archibald Geikie, Life of Sir Roderick Murchison.. Based on His Journals and Letters With Notices of His Scientific Con- temporaries and a Sketch of the Rise and Growth of Palaeozoic Geology in Britain, 2 vols. (London, 1875), which also includes a fairly full list of Murchison’s publications.
M. J. S. Rudwick
Sir Roderick Impey Murchison
Sir Roderick Impey Murchison
The British geologist Sir Roderick Impey Murchison (1792-1871) established the Silurian as a new geological system and cofounded the Devonian system.
Roderick Murchison, descended from an old Highland family, was born in Scotland on Feb. 19, 1792. After a time in the army in the Peninsular War, he married and, having ample means, took up fox hunting and an interest in art and antiquities. Influential friends, aided by his wife, persuaded him to pursue a scientific career, and from the age of 32 he devoted himself to geology.
In 1831 Murchison began his great research into the mass of hitherto geologically unknown graywacke rocks, that is, Lower Paleozoic, underlying the Old Red Sandstone in South Wales and the Welsh Borderland. His monumental work The Silurian System (1839) contained a description of the sequence of the graywacke rocks and their fossils. In the same year he and Adam Sedgwick established the Devonian system. In 1841, after explorations in Russia with French colleagues, he proposed the name Permian for yet another worldwide geological system, the uppermost of the Paleozoic. The Geology of Russia in Europe and the Ural Mountains was published in 1845. The book Siluria (1854 and subsequent editions) surveyed those ever-widening regions which he was incorporating in his Silurian domain.
Murchison was involved in the two most important geological controversies of the 19th century. The first was the unfortunate and bitter argument over the Cambrian and Silurian systems, in which the other protagonist was Sedgwick. Here Murchison's case was undoubtedly the stronger. The other was the crucial question of the geological structure of the Highlands of Scotland. Here Murchison was only involved retrospectively, and it turned out that his interpretation was wrong.
In 1855 Murchison became director general of the Geological Survey of Great Britain. Meanwhile he had presided over the Geological Society, the Geographical Society, and the British Association for the Advancement of Science. He was knighted in 1846 and was made a baronet in 1866. Among his many honors from British and foreign institutions was the Wollaston Medal, the highest award of the Geological Society.
Murchison was one of the most distinguished geologists of the 19th century. His liberality and social position plus the pride he took in his science were of immense value in furthering the cause of learning in Britain. He died in London on Oct. 22, 1871.
The standard biography of Murchison is Sir Archibald Geikie, Life of Sir Roderick I. Murchison (2 vols., 1875). Murchison's connection with the Geological Society of London is narrated in Horace Bolingbroke Woodward, History of the Geological Society of London (1908), in which there is also an impartial discussion of the Cambrian-Silurian controversy. Sir John Smith Flett, The First Hundred Years of the Geological Survey of Great Britain (1937), and Sir Edward Bailey, Geological Survey of Great Britain (1952), give detailed accounts of Murchison and his tenure as director general.
Murchison, Roderick Impey
Sir Roderick Impey Murchison
Sir Roderick Impey Murchison
Scottish geologist who first described rocks of the Silurian system in England and conducted geologic mapping of Russia. One of the most distinguished geologists of the nineteenth century, Murchison was important in establishing the Permian and Devonian systems, and helped to put geologic time and events in the history of life on earth into a more understandable chronological and theoretical framework. He was named the director of the Royal School of Mines and director-general of the Geological Survey.