Exploration Insights Great Geos ebook | Page 40

40 | Great Geologists claimed the Lower Silurian as Cambrian. Sedgwick also recognised that there was an unconformity between the “Lower” and “Upper” Silurian and that the term Silurian could be not used beneath this break. Murchison insisted there was no unconformity. A flavour of the acrimonious debate is given in this description by Andrew Ramsay of the presentation of a polemic paper by Sedgwick in February 1852 to The Geological Society of London. “Good scrimmage between Sedgwick and Murchison on the Lower Silurian and Cambrian question. It was not an enlivening spectacle. Sedgwick used very hard words”. Matters were not truly resolved until a few years after the deaths of Murchison and Sedgwick, when Charles Lapworth placed the problematic strata within his new Ordovician System based on their graptolite faunas. He was committed to defining an ordered and mappable stratigraphy (in 1855 he was made Director General of the Geological Survey) and indeed controversy persists even today on where the precise limits of geological periods should be drawn. That he tried to resolve these issues through field work, biostratigraphy and structural relationships is to his credit. That he tried to browbeat those who opposed him is not. Murchison was perhaps the ultimate “gentleman geologist”. His position in society allowed him to converse with governments and nobility and there is little doubt that he saw the advancement of geological and geographical knowledge as advancing the British Empire (he was a founder of the Royal Geographical Society and served as its President on multiple occasions). For his efforts he was knighted in 1846 and made a Baronet in A final controversy engaged Murchison in 1866. The list of honours he received from his later years, when, failing to recognise both British and international scientific their position above the Moine Thrust, he societies are numerous. Nineteen stars, argued that a series of ancient gneiss, now crosses and other emblems of distinction known to be Precambrian, could not be were awarded to him by sovereigns of older than Silurian. many nations. Before his death in 1871 he endowed a Chair in Geology at Edinburgh It would be unfair to characterise University and a medal and research fund Murchison as the villain in these at The Geological Society. His legacy controversies and that he was always on lives on too in many fossils that bear his the wrong side of the scientific arguments. name (e.g. Didymograptus murchisoni, Fossiliferous Wenlock Limestone (Silurian) from Wren’s Nest, Dudley. the “tuning-fork” graptolite, a favourite of paleontology students everywhere) and in the name of geographical features such as the Murchison River in Western Australia. He was truly the King of Siluria. REFERENCES This essay has drawn upon information from the following sources: Gohau, G. 1990. A History of Geology. Rutgers University Press. 259pp. Hallam, A. 1983. Great Geological Controversies. Oxford University Press, 244pp. Morton, J.L. 2004. King of Siluria. Brocken Spectre Publishing 280pp. Oldroyd, D.R. 1990. The Highlands Controversy. The University of Chicago Press. 438pp. Rider, M. 2005. Hutton’s Arse. Rider-French Consulting Ltd. 214pp. Rudwick, M.J.S. 1972. The Meaning of Fossils. The University of Chicago Press, 287pp. Secord, J.A. 1986. Controversy in Victorian Geology: The Cambrian-Silurian Dispute. Princeton University Press, 363pp. Stafford, R.A. 1989. Scientist of Empire. Cambridge University Press. Silurian Trilobite (Calymene blumenbachi) from Wenlock Limestone, at Wren’s Nest. Known colloquially as the ‘Dudley Bug’, this fossil features in the Coat of Arms of the town of Dudley.