Lapworth, Charles

views updated May 11 2018

Lapworth, Charles

(b. Faringdon, Berkshire, England, 20 September 1842; d. Birmingham, England, 13 March 1920),

geology.

Lapworth’s early life was spent in Berkshire and Oxfordshire. In 1864 he became a schoolmaster in southern Scotland. Although his education and scholastic work were purely literary, he soon developed a genius for geological research, in which he engaged intensively during holidays in the surrounding countryside. In 1881 he was appointed to the newly established chair of geology at Mason College (now Birmingham University) and during the first two years there made long and arduous excursions into the northwest of Scotland. His health broke under the strain, and he never fully regained his strength. During his thirty years at Birmingham he taught, lectured, wrote, and advised with fruitful energy and made important contributions to geological knowledge of the English Midlands. He was awarded a Royal Medal by the Royal Society in 1891 and the Wollaston Medal by the Geological Society (its highest honor) in 1899.

Lapworth’s investigations into the geology of the Southern Uplands of Scotland in the first phase of his career were epochal because they revolutionized the interpreration of the structure of that important region. A group of fossils, the graptolites, which he used for dating Lower Paleozoic rocks were the means by which he unraveled complicated regional structures. He combined large-scale geological mapping of critical areas with the exhaustive collection of graptolites from the black shale bands (to which they were confined) and the exact discrimination of species to establish his dating method. In the central area, around Moffat, which he studied first, Lapworth found that the numerous shale-band outcrops, which had been thought to represent separate bands at successive horizons in an enormously thick ascending series of strata, were in reality repetitions of a comparatively few bands that were a series of overfolds in which the limbs had become more or less parallel by compaction (isoclinal folding). He demonstrated that the strata, which could be shown to be middle or upper Ordovician and lower Silurian in age, here formed one condensed series only about 250 feet thick (1878). In the Girvan region to the west, the strata, though found to contain graptolite-bearing shale bands, were of quite different lithological types, containing shelly fossils and trilobites. By correlating these bands with the similar bands at Moffat, Lapworth showed that the Girvan rocks, spanning the same time range, were similarly complicated in structure and some twenty times as thick (1882)

From a study and comparison of his own collection of graptolites with collections made in other parts of the world, he tabulated a series of twenty graptolite zones (1879-1880) which seemed to be generally applicable and finally (1889) gave a comprehensive account of the stratigraphy of the Southern Uplands. These results were amplified and confirmed, respectively, in two major works on British paleontology and geology, the Monograph of British graptolites (1901-1918) and the Geological Survey Memoir on southern Scotland (1899). Lapworth’s work inspired research into the working out of the detailed stratigraphy of other British regions by means of the graptolites, particularly by Nicholson and Marr in the English Lake District (1888), Gertrude Elles and Ethel Wood in the Welsh Borderland (1900), and O.T. Jones in central Wales (1909).

Meanwhile, Lapworth had proposed (1879) a major classification of the Lower Paleozoic rocks into three systems: Cambrian, Ordovician (a new system), and Silurian. This proposal was so reasonable and convenient on general geological grounds, and provided so satisfactory a solution to the Sedgwick-Murchison controversy over “Cambrian” and “Silurian,” that it was immediately and almost universally accepted.

Lapworth’s investigations in the Northwest Highlands of Scotland helped to resolve the controversy that was beginning to rage as to the nature of the junction between the Cambrian-Ordovician and the Moinian, a question which affected the interpretation of the structure and history of the entire Scottish Highlands and possibly of other British regions. In the Northwest Highlands there are four main rock groups: gneiss (Lewisian, Pre-Cambrian, in modern terminology and age assignment), overlain unconformably by red sandstone (Torridonian, Pre-Cambrian), overlain unconformably by Cambrian-Ordovician quartzites and limestones, and schists (Moinian) physically overlying the Cambrian-Ordovician with about the same low dip to the east. It had been assumed by Murchison (1858-1860) that there was a conformable upward passage from the Cambrian-Ordovician into the Moinian, but faulting of various kinds had been suggested by Nicol (1861) and Callaway (1881). Lapworth, after painstaking researches (1883), found that the junction was a thrust and that the present character of the Moinian was undoubtedly produced by metamorphism at some post-Ordovician time. He left open the question of the age and character—and thus the correlation—of the original rocks that had become metamorphosed to form the Moinian. (It is now thought probable that these rocks were the Torridonian.) His interpretation was entirely confirmed and greatly extended by Peach and Home of the Geological Survey, under the direction of Archibald Geikie. Lapworth’s work in both the Uplands and the Highlands impressed him with the importance of tangential stress in the earth’s crust throughout geological time.

In the last phase of his career Lapworth, with Birmingham as a center, and using the same insight that he had shown in his work in Scotland, investigated the surrounding rocks, directing his attention chiefly to the Lower Paleozoic inliers. Certain quatizites abnd sandstones as well as igneous rocks in these inliers were already strongly suspected of being, respectively, Lower Cambrian and Pre-Cambrian. Lapworth found similar rocks in other inliers and confirmed these ages by discovering unmistakable Lower Cambrian fossils, of which the Olenellus type of trilobite in Shropshire was particularly important. He mapped much of the Cambrian rocks in north Wales and the Pre-Cambrian, Cambrian, and Ordiovicaian rocks in Shropshire; but his work on the old rocks of Wales and the Midlands was largely left to be carried on by others. Lapworth also did important work on other aspects of Midland geology: the Coal Measures (particularly concealed coalfields), the origin of Permian and Triassic breccias and conglomerates, glaciation, and river history.

BIBLIOGRAPHY

Original Works. Among Lapworth’s more important works are “The Moffat Series,” in Quarterly Journal of the Geological Society of London, 34 (1878), 240-346; “On the Tripartite Classification of the Lower Palaeozoic Rocks,” in Geological Magazine,16 (1879), 1-15; “On the Geological Distribution of the Rhabdophora,” in Annals and Magazine of Natural History, 5th ser., 3 (1879), 245-257, 449-455, 4 (1879), 331-341, 5 (1880), 45-62, 273-285, 358-369, 6 (1880), 16-29, 185-207; “The Girvan Succession,” in Quarterly Journal of the Geological Society of London,38 (1882), 537-666; “The Secret of the Highlands,” in Geological Magazine,20 (1883), 120-128, 193-199, 337-344; “On the Close of the Highland Controversy,” ibid., 22 (1885), 97-106; “On the Discovery of the Olenellus Fauna in the Lower Cambrian Rocks of Britain,” ibid., 25 (1888), 484-487; “On the Ballantrae Rocks of the South of Scotland and Their Place in the Upland Sequence,” ibid., 26 (1889),20-24, 59-69; “The Geology of South Shropshir,” in Proceeding of the Geologists’ Association,13 (1894), 297-355, written with W.W.Watts; “A Sketch of the Geology of the Birmingham District,” ibid., 15 (1898), 313-416; and A Monograph of British Graptolites (London, 1901-1918), of which he was editor; “The Hidden Coalfields of the Midlands,” in Transactions of the Institution of Mining and Metallurgy, 33 (1907), 26-50.

II. Second Literature. On Lapworth and his work see (listed chronologically) B. N. Peach and J. Horne, The Silurian Rocks of Britain, Vol. I, Scotland (Memoirs of the Geological Survey of Great Britain, 1899); Anon., “Eminent Living Geologists: Professor Charles Lapworth,” in Geologistical Magazine, 38 (1901), 289-303; B. N. Peach, J. Horne et al., The Geological Structure of the North-West Highlands of Scotland (Memories of the Geological Survey of Great Britain, 1907); W. W. W[atts], obituary notice in Quarterly Journal of the Geological Society of London, 77 (1921), lv-lxi; W. W. W“atts” and J. J. H. Teall, obituary notice in Proceeding of the Royal Society, 92B (1921), xxxi-xl; W. W. Watts, “The Author of the Qrdovician System: Charles Lapworth,” in Proceeding of the Birmingham Natural History and Philosophical Society, 14 (1921), special suppl.; a revised version in Proceeding of the Ge-ologists’ Association, 50 (1939), 235-286; W. S. Boulton et al., “The Work of Charles Lapworth,” in Advancement of Science, 7 (1951), 433-442; and E. B. Bailey, Geological Survey of Great Britain (London, 1952).

John Challinor

Lapworth, Charles

views updated May 08 2018

Lapworth, Charles (1842–1920) An English geologist, Lapworth was responsible for ending the controversy between Murchison and Sedgwick over the Lower Palaeozoic, by proposing in 1879 that the area in dispute should form a third system, the Ordovician. He also published a classification of graptolites (1873), and worked on the structure of the Scottish Highlands, identifying the Moine thrust.

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