June/July 2007

Economic Geology

The Basalt Controversy (Part 18)

By R. J. Cathro

“The formation in 1835 of the Geological Survey, which was the first ... of any country, (followed) the ‘Heroic Age of Geology’, when the foundations of the Science were laid down by Hutton, Werner and William Smith and consolidated by Cuvier and Lamarck. Its early days coincided with the ‘Golden Age of Geology’, when such Masters as Lyell, Sedgwick, Murchison, Buckland and De la Beche accomplished wonders in strenuous pioneering field-work and made many great discoveries.” (Smith, 1936)

Even while Werner was at the height of his influence as the leader of the Neptunists (see Part 16), a few German geologists had attempted, without success, to challenge his ideas on the origin of basalt. One of the first was Rudolf Erich Raspe (1771), who recognized that columnar basalt along the lower Rhine River was volcanic (Sigurdsson, 1999, p. 142-143). He is better known as the author of ‘Baron Münchausen’s Narrative of his Marvellous Travels.’ Another serious critic was one of Werner’s first students, J.K.W. Voigt, who disputed his interpretation of the Scheibenberg basalt (Sigurdsson, 1999, p. 117; see Part 16).

As time went by and many locations were found in France, Italy, and Britain, where volcanic and granitic rocks could be observed cutting sediments and each other, Werner’s ideas on basalt became more suspect. Even worse, some of his most famous students became advocates rather than critics of Vulcanism as they travelled the globe and began to realize that the field evidence didn’t support what they had been taught. These included: Leopold von Buch, probably Werner’s most illustrious protégé (Sigurdsson, 1999, p. 123); Jean Baptiste Barthelémy de Lessups, who observed active volcanoes in Kamchatka in 1790; Alexander von Humboldt, who witnessed the eruption of Cotopaxi in Ecuador in 1803 and wrote classic descriptions of the natural history of South America; and William Maclure, who published the first geological map of the United States in 1809. By the time of Werner’s death in 1817, his theories about the ‘universal formation’ and the sedimentary origin of basalt were badly tarnished and rejected by everyone except Robert Jameson.

In the years following Hutton’s death in 1797, the task of explaining his theory more clearly and defending his reputation from his critics fell to the two friends from the University of Edinburgh who had accompanied him on the 1788 trip to Siccar Point, John Playfair and Sir James Hall (see Part 17). Playfair has been called Hutton’s Boswell, after the great author and diarist James Boswell (1740-1795) who wrote the great biography of Samuel Johnson. In addition to being a mathematician, he was a dedicated amateur geologist and a fine writer. Gould (1987a, p. 93) judged him to be even better, perhaps, than the great 19th century geologists and literary stylists Charles Lyell and T.H. Huxley. Playfair published an articulate and simplified explanation of Hutton’s ideas called ‘Illustrations of the Huttonian Theory’ in 1802.

Hall, a fine chemist, performed an equally important function, although he had to wait until after Hutton died because he was so opposed to anything but fieldwork. Hall conducted an elegant series of tests, believed to be the first examples of experimental geology, in order to prove Hutton’s contention that basalt was derived from the cooling of molten rock. He melted 15 samples of basalt from Scotland, England, and the continent and showed that they produced glass when cooled quickly, but yielded a granular structure like basalt when cooled slowly (Ashworth, 2004, p. 76). His next series of 500 experiments, which took six years to complete (in 1805), proved that limestone would not disintegrate if heated to 1,000°C, as it would at surface, if it was under a pressure equivalent to a 2,700 m column of seawater (Repcheck, 2003, p. 170-173). “Hall proved… that it was quite reasonable to believe that… basalt, greenstone and whinstone in the neighbourhood of Edinburgh were ultimately of volcanic origin” (Flett, 1937, p. 12).

Although he was only interested in the history of the earth and never mentioned mineralization, we can see with the benefit of hindsight that Hutton had an enormous impact on our understanding of the origin of ore deposits. And yet, modern academics still dismiss his contributions, as in this example written by an eminent paleontologist, evolutionary biologist, and essayist on natural history: “Hutton had precious little impact on the practice of geology … his theory remained on a periphery of speculation; the doers of geology largely ignored his contribution and went about their work” (Gould, 1987b, p. 79).

The Geological Society of London, founded in 1807, played a vital role in the advancement of geological knowledge in Great Britain; its Transactions contain a series of classic memoirs that are its foundation stones. The founders decreed that the emerging science of geology needed hard data from the field, not theories and interpretation, and banned all theoretical discussion from their meetings. This was actually written into the procedures of the society. The membership included members of the peerage, Members of Parliament, great landowners, bankers, and “Anglican gentlemen, who viewed the Geological Society as their intellectual home” (Gould, 1987b, p. 85). They were able to exert considerable influence on the government. Geology was becoming something more than a hobby for wealthy amateurs; it was developing into an integral part of natural philosophy. The leading professors were Adam Sedgwick at Cambridge and William Buckland at Oxford.

The society chose the stratigraphic research program (the geological time scale) as its focus, defining the primary task of geology as “unravelling the sequence of actual events in time, using the key to history that had just been developed to the point of general utility by Cuvier (in the Paris Basin) and William Smith (in southern England)—the distinctively changing suite of fossils through time” (Gould, 1987c, p. 152). Fortunately, the sequences in these regions are relatively simple and undisturbed and “the time scale was established in an amazingly fruitful burst of research during the first half of the nineteenth century.

By 1850, history had been ordered in a consistent, worldwide sequence of recognizable, unrepeated events, defined by the ever-changing history of life, and recorded by a set of names accepted and used in the same way from New York to Moscow” (Gould, 1987b, p. 76-77). In 1859, the society awarded its highest honour, the Wollaston Medal, to Charles Darwin, who served as secretary from 1837 to 1841.

Another important development was the founding of the Geological Survey of Great Britain in 1835, which provided the first opportunity for steady employment for geologists outside the universities and the mining industry. Most of this section on the survey is derived from Flett (1937). The Survey, which became the model for most similar government agencies worldwide and the source of the future leaders for most of those in the British colonies and dominions, was extremely fortunate in its early leadership. Sir Henry Thomas De la Beche (1796-1855) served as the first director from 1835 to 1855 and was succeeded by Sir Roderick Impey Murchison (1792-1871) between 1855 and 1871.

De la Beche, who became director at the age of 39, had grown up in Devonshire and Dorset in a military family and lacked the wealth to work as a gentleman scientist. He had travelled widely outside the country, was fluent in several languages, and had a natural aptitude for field mapping and geological cartography, of which he was a pioneer. Because of his strong interest in economic geology and his ability to collaborate well with mining engineers, he began his mapping in the more complex geology of Cornwall and Devon before moving to southern Wales, which was important for its coal resources. It was there that he met a self-taught employee of a coal company whose accurate and detailed maps were ahead of anything being produced in England up to that time. The employee was Canadian-born William E. Logan (1798-1875), who had attended the University of Edinburgh for one year and then worked for ten years in London for his family as a bookkeeper before moving to Wales in 1828 to work for the family coal mining company. He became the founder of the Geological Survey of Canada in 1842, with a strong recommendation from De la Beche.

In 1855, the 63-year-old Murchison was at the height of his fame and was, with the possible exception of Lyell, regarded as the leader of British geology. He had defined the Silurian and Permian periods and was co-founder of the Devonian. He was “an aristocratic old soldier, … self-assured and curt almost to the point of egomania” (Gould, 1987b, p. 87), and proud of his Highland roots. Murchison was also described as a diligent and excellent scientist, although his field methods were considered to be rapid and superficial. His high social standing, substantial wealth, personal friendship with influential politicians and members of the aristocracy, and forceful but genial personality made him an eminently successful administrator. Unfortunately, he had little interest in the economic applications of geology, which had been of prime importance to De la Beche, nor was he much concerned with the education of students of mining and metallurgy. De la Beche, who had established three sister organizations, The School of Mines (the prefix Royal was added about 1862), the Mining Record Office, and the Museum of Practical Geology, had wanted to pattern the school after the well-known academies in Saxony and France. 

With the leading universities, learned societies, and geological surveys in Europe so focused on stratigraphy and paleontology, the study of economic geology was restricted to small groups working in relative isolation in Cornwall, Saxony, Scandinavia, France, and elsewhere. The situation in England in the middle of the 19th century has been summarized by Rickard (1910, p. 479) as follows:

"In England, the detection of fossils and the correlation of strata absorbed the attention of geologists to the exclusion of investigation into the nature of mineral aggregates that are the object of mining. Indeed, not only did geology give the cold shoulder to mining but when geologists condescended to be interested in mineral deposits, they made blunders highly perplexing even to those willing to accept scientific aid. Thus Murchison rashly enunciated the generalization that the Silurian rocks were particularly favourable to gold veins, basing this broad statement on his knowledge of the Ural region; and when gold was discovered in Australia in slate and sandstone of Silurian age, he congratulated himself on the confirmation of his dictum. Later, he interpreted the scanty data at his disposal as warranting the inference that deep mining in the solid quartz rock is usually unprofitable. No wonder that the miner looked askance at the geologist, so that there was a lack of co-operation between the young science and the venerable industry. Moreover, the idea obtained in England that geology stooped to commercialism when she concerned herself with mining.

The notion long persisted that science suffered by becoming utilitarian; the geologist deemed hunting for fossils more becoming than the search for ore; and this tradition in effect prevented English geologists from attempting to unravel the complexities of ore occurrence. A notable example is afforded by the Geological Society. … In its records will be found … the principles that constitute the very foundations of the science. … Yet the sum total of information concerning ore deposits to be found in the (Transactions) is negligible. Englishmen as geologists occupy a position second to none; as contributors to the study of ore deposits they are nowhere. … I impute the poverty of result entirely to the fact that men of culture have deemed it undignified to make a commercial use of scientific knowledge."

A dramatic change in attitude was needed if economic geology was ever going to break out of this period of disinterest. The triggering event took place in January 1848, although nobody could have foreseen how a placer gold discovery on the Pacific coast of North America could have such momentous results.

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