Adams, Frank Dawson

(b. Montreal, Canada, 17 September 1859; d. Montreal, 26 December 1942), geology.

Adam’s father, Noah Adams, belonged to the distinguished Adams family of New England; his mother, Frances Tait Dawson, was a United Empire Loyalist from Northern Ireland. At nineteen he graduated with first rank honors in natural science from McGill University, where he came under the influence of the scholarly principal, J. W. Dawson (no relation), and the versatile and, magnetic B. J. Harrington of the department of chemistry and mineralogy. Comfortable family financial circumstances allowed Adams to study chemistry and mineralogy at Yale University (1878–1879), and later to attend several sessions at Heidelberg University.

After spending 1880 to 1889 in government service, Adams joined the staff at McGill as lecturer (1890–1893); he followed Dawson as holder of the Logan chair of geology in 1893. Adams became dean of the Faculty of Applied Science in 1908 and dean of the Faculty of Graduate Studies in 1922. He retired in 1924, after thirty-five years of arduous service. He was deeply but quietly religious. His History of Christ Church Cathedral (1941) was a tribute to the church to which he was devoted and to his wife, Mary Stuart Finely, to whom the book was dedicated. Adams also found time to devote to many philanthropic and social benevolences.

Adams belonged to numerous scientific societies, including the Royal Society of London, the Geological Society of America (of which he was president in 1918), the Royal Society of Canada (president in 1913; Flavelle Gold Medal in 1937), and the Geological Society of London (Lyell Medal in 1906; Wollaston Medal in 1939). He was also president of the Twelfth International Geological Congress (Montreal, 1913). He received honorary degrees from McGill, Toronto, Queen’s and Mount Allison universities, and Bishop’s College.

In 1880 Adams joined the Geological Survey of Canada as assistant chemist and lithologist. One of the first tasks given him by the director, A.R.C. Selwyn, was to determine the nature and origin of certain rocks from southern Quebec. In order to work out these derivations and associations, Adams requested, and was granted, leave of absence to master the new petrographic technique being developed by H. Rosenbusch at Heidelberg. He completed this work to Selwyn’s satisfaction and was next assigned to study areas of partly foliated anorthosites in southwestern Quebec that William Logan had considered to be the upper and stratified portion of the Laurentian series. To this difficult task he applied his newly won skill in the use of the petrographic microscope, an instrument with which he had become familiar in Heidelberg and which he was probably the first in Canada to use. He was able to demonstrate conclusively not only the igneous origin of the anorthosites but also the sedimentary origin of some of the Grenville crystalline rocks upon which Logan had supposed the anorthosites rested. The presentation of the results of this study gained him the Ph.D. summa cum laude at Heidelberg. The publication of his thesis (1893) established Adams as one of the North American experts in the use of the petrographic microscope. Several publications resulted from his work with the Geological Survey, among the more important being descriptions of Precambrian rocks north of Montreal and St. Jerome (1896), based on field work carried out from 1885 to 1891.

The Laurentian system had been considered by Logan to consist of two divisions, the lower a complex of metamorphosed sedimentary rocks, which he named Grenville and Ottawa, and an upper, or Norian, division, made up largely of anorthosite, which was considered to be an altered and crystallized sediment. This anorthosite, well exposed around Morin, Quebec, was very carefully inspected by Adams, who showed that it was composed largely of plagioclase feldspar, with few accessories. He established its igneous nature both by his petrographic determinations in the laboratory and by the intrusive contacts with the Grenville rocks that he was able to demonstrate in the field. He attributed the marked differences in grain size to crystal fracturing, which in places was carried to granulation. He also recognized that the Laurentian granites, then supposed to be the oldest rocks of the Canadian shield and possibly part of the original crust, were intrusive into metamorphic rocks, which therefore must have preceded them in time and space. These conclusions were among the foundations upon which the modern classification of the Precambrian series rests.

After leaving the Geological Survey and joining the staff of McGill, Adams devoted the summers of 1902 to 1908 to the mapping and description of the forbiddingly difficult Haliburton and Bancroft areas of southern Ontario. In his report (1910), written with A.E. Barlow, who had collaborated with him during the later years of the project, he showed that the oldest rocks were highly metamorphosed sediments, now gneisses, schists, quartzites, and marbles, and assigned them to the Grenville series. He found widespread intrusions of granite, diorite, and gabbro penetrating the Grenville rocks, and correctly attributed most of the metamorphism to the thermal effects of the abundant granite bodies. Adams noted that the metamorphism of the stratified rocks became more intense and the sedimentary rocks were “fretted away and [ultimately] represented only by occasional shreds and patches of amphibolite,” as the intrusive granites were approached. His discovery of nepheline syenite adjacent to granite and marble bodies was of great scientific importance, and paved the way for their later industrial exploitation. Because of the clarity of the writing, the painstaking carefulness of the descriptions, and the logical deductions, Adams’ report has become one of the classics of Canadian geology.

At McGill, Adams could not fail to be impressed by the peculiar rocks of Mount Royal. He found that the same general rock types prevailed in the halfdozen prominent hills dotted across the Paleozoic plain between Montreal and the Appalachian front. He announced the occurrence of these remarkable rock types in his paper “The Monteregian Hills: A Canadian Petrographical Province” (1903).

Close study of the deformed foliated gneisses and schists of the Grenville area had stimulated Adams’ curiosity concerning the causes of such structures and the possibility of their being duplicated in laboratory experiments. Aided by colleagues in the engineering laboratories at McGill, he started a sequence of experiments, spread over the first decade of the present century, utilizing a gigantic (for that time) press in which he could subject rocks to enormous pressures. High pressures had long been used to test the strength of cubes of rock to determine architectural suitability; but to duplicate the conditions within the earth’s crust, Adams subjected cylinders of rock encased in metallic tubes to compression under high confining pressures—for the most part less than 20,000 pounds per square inch but on one occasion 296,725 pounds per square inch. Manipulation of the apparatus allowed Adams to develop differential stresses and presumably to imitate the conditions under which some of the foliated rocks may have originated; he was also able to correlate some of the experimentally developed structures with natural ones observed in the field. The influence of this work upon our understanding of metamorphic processes is profound, and it has contributed is no small measure to the development of modern ideas of mountain building.

Adams’ first paper in this field, written with J.T. Nicholson, concerned a thumb-size cylinder of Carrara marble that he exposed to a confining pressure of 18,000 pounds per square inch; after 124 days the column had shortened by 11.4 percent of its original height. Examined microscopically, it showed many of the characteristics peculiar to the Grenville marbles. Never before had properties of metamorphic rocks been imitated in controlled experiments. Adams returned to this topic several times, and by using the highest available pressure, 296,725 pounds per square inch, he developed in his samples a schistose structure essentially similar to that of some highly metamorphic calcareous rocks. One interesting result was his discovery that quick-loading techniques caused calcite to yield to stress along intergranular slip planes, giving a cataclastic structure, whereas slow increase in loading produced intra crystalline polysynthetic twinning.

Other experiments were designed to record the plasticity of rocks under high pressures, up to 200,000 pounds per square inch. Most soft materials were easily deformed, but the harder rocks, such as granite, failed along fracture lines, yielding zones of granulation; this corroborated Adams’ own early ideas of the granulation of anorthosite by crystal fracturing. Other studies were directed to the determination of the depth at which pressure would close cavities in rocks. In granite, one of the least plastic rocks, Adams determined that cavities could exist as deep as eleven miles below the surface. One of his last papers on experimentation (1917), written with J.A. Bancroft, showed that the strength of rocks increases with pressure, and hence with depth in the crust, the conclusion being that rocks at great depth have great strength. To Adams must go the credit for establishing this phase of geological investigation upon a sure engineering foundation. His reputation as a pioneer in the field is secure.

In the decade following his retirement from active participation in university affairs, he and Mrs. Adams traveled widely, and following their third visit to Ceylon, he published the first complete geological report and map of that island (1929). Adams had always been intrigued by the beginnings of geological thinking, and during his travels he visited most of the Old World universities whose libraries held a wealth of early geological treatises. Wherever he could, he acquired early writings and amassed what was certainly the greatest such collection in private hands (now kept, intact, at McGill). This formed the basis for his scholarly work Birth and Development of the Geological Sciences (1938), a text that will long remain a standard treatment of the subject.

BIBLIOGRAPHY

1. Original Works. Complete listings of Adams’ geological papers relating to North America are in United States Geological Survey Bulletins 746, 823,937,1049 and 1195. His most important works are “Notes in the Microscopic Structures of some Rocks of the Quebec Group,” in Geological Survey of Canada, Report of Progress for 1880–1882, Part A (1883), 8–23: “Ueber das Norian oder Oberlaurentian von Canada,” in Neues Jahrbuch8 (1893), 419–498; trans. in Canadian Record of Science (1895–1896), 169–198, 277–305, 416–443; “Report on the Geology of a Portion of the Laurentian Area Lying to the North of the Island of Montreal,” in Geological Survey of Canada, Annual Report (New Series), 8 , Part J (1896); “The Monteregian Hills: A Canadian Petrographical Province,” in Journal of Geology, 11 (1903), 239–282; “An Experimental Investigation Into the Flow of Marble,” in Royal Society of London, Philosophical Transactions (Section A), 195 (1901), 363–401, with J. J. Nicholson: An Investigation Into The Elastic Constants of Rocks, More Especially With Reference to Cubic Compressibility, Carnegie Institute Publibation 46 (Washington, 1905), with E.G. Coker; “An Experimental Investigation Into the Action of Differential pressure of Certain Minerals and Rocks,” in Journal of Geology, 18 (1910), 489–525; “An Experimental Investigation Into the Flow of Rocks—the Flow of Marble,” in American Journal of Science, ser. 4, 29 (1910), 465–487; “An Experimental Investigation Into the Flow of Rocks” [With discussion], in Eleventh International Geological Congress, Comples rendus, 14 (1912), 911–945: “On the Amount of Internal Friction Developed in Rocks During Deformation and on the Relative Plasticity of Different Types of Rocks” in Journal of Geology, 25 (1917), 597–637, with J.A. Bancroft; “Earliest Use of the Term Geology.” in Geological Society of America Bulletin, 45 (1934), 375–424; The Birth and Development of the Geological Sciences (Baltimore, 1938); and History of Christ Church Cathedral (Montreal, 1941)

II. Secondary Literature. Of the many biographies the following are selected: H.M. Tory, “Frank Dawson Adams (1859–1942),” in Royal Society of Canada Proceedings, ser. 3, 37 (1943), 69–71; J.A. Dresser, “Memortial to Frank Dawson Adams,” in Geological Society of America Proceedings 1944 (1945), 143–150; and J.W. Flett, “Frank Dawson Adams 1859–1942,” in Royal Society of London, Obituary Notices of Fellows, 4 , no. 12 (1943), 381–393.

Thomas H. Clark