Extracts from the Proceedings for 1870-1871 (Session 13)
Mr. D. C. GLEN, C.E., laid before the meeting several slabs of oil shale from near Collingwood, on Lake Huron, Canada; and also some samples of the petroleum distilled from it. The slabs were from the Silurian formation, which is of great extent in North America, and remarkable for the regular succession of its strata. When examined, these blocks of shale were found to be stratified horizontally with layers of Trilobites, Entomostraca, and other marine organisms. It was from the prodigious abundance of these creatures over this track of the ancient sea-bottom that the slabs now referred to had derived their bituminous properties.
The oil shown was distilled from the shale in the usual manner, by heated retorts. The pure, clear spirit is taken from the oil, leaving a thick residuum which is used for tarring outside work, and also for burning in steam-boiler and other furnaces. Another sample of oil on the table was pumped up from a bored well at Bothwell, C.W. (Canada West, the former name for Ontario), where the oil occurs at a depth of from 100 to 500 feet from the surface. When pumped out, it is mixed with three or four times its bulk of salt water. It is then allowed to settle in large tanks, and when the water is drawn off from below, it leaves the oil in very much the same state as that distilled from the shale. In all probability, therefore, this oil is derived from a similar stratum, impregnated with organic animal matter.
A collection of phosphates from Charleston, U.S., was exhibited by Mr. Potts and Mr. Naismith, together with some large fossil teeth, vertebrae &c, from the same locality. Mr. Potts stated that large quantities of these phosphates are being used in America, and also imported into this country, for the manufacture of artificial manures. The specimens on the table had been collected from some cargoes lately brought to the Clyde. The deposit from which they are taken is found along the banks of many of the rivers in South Carolina, and immediately under the surface soil of the land lying between; and is supposed to underlie a large portion of the coast and sea-island region of that part of America. It consists of layers, varying from six inches to several feet in thickness, of irregularly rounded nodules, mixed up with an immense quantity of bones—ribs, vertebrae, tusks—of various species of animals, all more or less petrified. The nodules yield 50 to 60 per cent, of bone phosphate; while from some of the bones as much as 80 to 85 per cent. of this fertilising substance had been obtained. The deposit, which only came into notice a few years ago, has already given rise to an important commerce both in the raw and manufactured article. Numerous companies have been formed in Charleston and its vicinity for phosphate digging and manufacture, and the planters have found the use of the manure, which is about one-third cheaper than guano, exceedingly profitable. The export of the raw material has also assumed considerable proportions ; and altogether this remarkable deposit is contributing in no small degree to the prosperity of South Carolina and the neighbouring States. Immediately below the deposit is a bed of white limestone marl of great thickness, which has been recognised as underlying all the country round. Mr. Potts then read several analyses, which he had obtained of these phosphates, showing the high percentage of fertilising matter which they contained. He also called attention to the large size of some of the teeth and vertebrae exhibited. It was evident the deposit was of comparatively recent age; but the precise geological period to which it belonged, and the nature of the organisms of which it was composed, he would leave to be elucidated by others.
The CHAIRMAN (Mr. John Young, Vice-President) said there could be no doubt this remarkable deposit of phosphates belonged to the Tertiary period, and probably its earlier division, the Eocene. The tertiary formation is largely developed along the southern coast of North America, stretching in a belt of considerable breadth from North Carolina to the Gulf of Mexico, and leaving the coastline only at the delta of the Mississippi. The thick bed of limestone marl, which had been referred to as underlying the deposit, probably belonged to the immediately preceding formation, the Chalk, which is found in New Jersey and North Carolina, and crops out at intervals farther south, from beneath the tertiary strata, between the Appalachian Mountains and the sea. The deposits in Britain most closely resembling these Charleston beds are those known as the “Bagshot and Bracklesham beds,” occurring in Surrey and Sussex. They belong to the middle-Eocene division of the tertiary, or more recent than the “London clay.” They contain numerous remains of fishes, some resembling the sword fish, teeth of sharks of various species, bones of crocodilian forms allied to the gavial, and some that were considered to belong to an extinct order of huge serpents. The whole series of fossils, like those before them, indicated a much warmer climate than now prevailed in that part of the world, and showed that the waters of the sea were teeming with large and powerful forms of life. Some of the sharks’ teeth found in these Bracklesham beds closely resembled those on the table from the Charleston deposit; but one or two of the latter, measuring about five inches long from root to point, and four inches broad, implied a species of shark of extraordinary magnitude, certainly not less than 60 feet in length. The largest living species, the white shark, sometimes attains a length of over 30 feet. Some interesting questions arose as to these thickly-strewn fossiliferous beds, which are found in all formations, restricted often to one particular “horizon,” but they are due, no doubt, to the circumstance of the creatures whose remains are found in them having frequented certain banks or stretches of coast, as we find is the case with the marine animals of the present day. Mr. Young concluded by conveying the thanks of the meeting to the exhibitors.
Extracts from the Proceedings for 1895-1896 (Session 38)
Mr. R. W. DRON, C.E. and M.E., exhibited several specimens of Altered Dolerite, which had taken the place of a coal-seam, from a coalpit in South Ayrshire, where it occurred at a depth of 130 fathoms. Similar intrusions are found in the Lanarkshire coal-field, where the dolerite, from its colour, is known as “White Horse.” Protruding itself from some dyke it runs laterally above or below a coal-seam or other stratified rock, burning it more or less, and sometimes rendering it columnar. In the course of its progress it usually thins out, loses its crystalline appearance, and becomes white and soft, sometimes even assuming almost the character of a pipeclay, in which state the miners’ wives use it for their hearths and doorsteps.
Mr. JAMES NEILSON, V.P., exhibited a number of specimens of Pholas and Saxicava, from Millport and other localities in the Firth of Clyde, with their chambers or burrows excavated in limestone and in volcanic ash, also one bored in calcite in volcanic ash, and as the latter rock had proved too tough for the art of the little mechanic, the result was that the excavation was quite lopsided. The question was afterwards discussed as to the means by which these boring molluscs make their excavations in the rock, whether mechanical or chemical, or a combination of both—and Dr. Young and Mr. John Smith gave their reasons for believing that the action is purely mechanical, the instrument employed being the foot of the animal probably with the help of sand-grains.
Mr. BELL spoke of the loss geological science had just sustained in the comparatively early death from typhoid fever of Mr. Hugh Miller, an esteemed member of the staff of the Scottish Geological Survey, and son of the well-known author of “The Old Red Sandstone.” In connection with, and outside of, the Survey work, the deceased gentleman had done much good solid geological work which gave promise of leading to still higher performance, a hope now unfortunately blasted.
Mr. JOHN YOUNG, LL.D., F.G.S, exhibited a series of Microscopic Slides mounted by a method which he had recently adopted, so as to show without much trouble the minute forms of crystalline structure which characterize the glassy Pitchstone Rocks of Arran, and which afford such beautiful and interesting objects for examination owing to their great and varied resemblance to minute forms of vegetable life. This method consists in crushing small portions of the rock between the jaws of iron pincers, and selecting the thinnest and most transparent fragments, which are afterwards neatly mounted on the usual form of glass slide, within a circle, and covered with Canada balsam, being then left for a time to harden and dry. They are then surrounded by a circle punched out of thin cardboard, which is gummed to the slide and furnished with a thin glass cover to protect the mounted flakes from dust. These fragments, if carefully selected, will appear under the microscope as little pictures of the various crystalline structures—each differing somewhat from the other, owing to the varying angles of fracture of the rock. The process is simpler and easier than the tedious old plan of cutting and grinding sections of the hard glassy rock to a thin transparency. Dr. Young also shewed in illustration of the above a number of drawings of the fern-like forms seen in pitchstone which were made by Mr. Samuel Allport, F.G.S., and published in the Geological Magazine for January, 1872.
Dr. Young then exhibited a specimen of Crystalline Quartz filling a Drusy Cavity in trap-rock, found in a quarry near Bridge of Weir, Renfrewshire. The specimen, which measures about 9 inches in length by 3 inches in width across its largest outer angle, has the inner walls of the cavity lined with numerous well-formed crystals of quartz, but its chief interest lies in the peculiar markings which stud the whole of the outer walls of the druse. These markings are imprinted over the surface of the quartz, and are seemingly the counterparts of a crystalline structure which once formed, or coated, the walls of the druse, but now no longer exist. They look very like the impressions which would be made by crystals of calcite, or carbonate of lime, of the hobnail variety. This would imply that after the formation of the cavity its inner walls were coated with a lining of calcite crystals, their place being probably then taken by thermal waters holding silica in solution. From this silica the quartz crystals now seen filling up the inner cavity of the druse would be afterwards developed, except at its wider end, till the silica had also ceased to be deposited within the druse before the filling up was completed. Long afterwards, during the decay and weathering of the traprock, the lime-crystals which had formed on the outer walls of the druse were dissolved away by eroding waters, leaving no traces of their existence beyond their impress on the base of the subsequently-formed quartz layer, which gave the outer walls of the druse a honeycombed appearance, the casts of the quartz standing out in relief with sharp edges between the lime crystals. This interesting specimen had been presented to the Hunterian Museum by Mr. George Barlas, a member of the Society.
Extracts from the Proceedings for 1920-1921 (Session 63)
Professor GREGORY, D.Sc., F.R.S., delivered a lecture entitled “The Future of Oil Supply.” Professor Gregory said the recent sharp rise in the price of petrol had been explained either as simple profiteering or as a warning that the demand for mineral oil was growing much faster than the supply. The temptations to reckless use were powerful. During the past twelve months the increase of the world’s shipping was estimated at 9 per cent. on tonnage; but the increase in the number of ships driven by oil and motors had been 35 per cent. The United States before the war had 4,000,000 motor vehicles. It was estimated that next year the number would be 10,000,000, and that American shipping would require 60,000,000 barrels of oil. In 1918 the United States supplied 69.15 per cent, of the total world’s production of mineral oil. The British Empire (including Egypt and Persia) produced 3.80 per cent.; but it consumed three times as much and was largely dependent on the United States. Experts said that the American present output could not be maintained for more than five years, that some of its chief oilfields would be exhausted within a couple of decades, and that its oil consumption was growing so fast that it would soon have to import instead of export oil. The prospects of increasing the oil supply were dependent on the development of existing fields and the discovery of new fields. The field from which the greatest increase might be expected was Mexico, and its yield was predicted to surpass that of the United States. Galicia was estimated to contain another 100,000,000 tons. The Russian yield was on the decline before the war, but the output had kept up remarkably. Among new fields Venezuela was the most promising, but little was generally known of the results of recent prospecting there. A second enlargement of the supply might come from the discovery of oil in areas where search had been discouraged by the predominant theory of the formation of oil pools. The most convenient reservoirs occurred where the beds were bent into arch-like upfolds; but in some of the most productive fields the oil did not come from the arches or “anticlines,” but from the downfolds (synclines). The search for oil had been in some areas on the wrong track owing to the predominance of the upfold theory. Aerial navigation would be seriously handicapped if in twenty years’ time the petrol supply had been reduced by the reckless use of mineral oil. The geological prospects of the world’s supply warned us that it would soon be necessary to consider the prohibition of the use of oil for purposes for which other fuels were available. The lecture was fully illustrated by lantern slides.
Mr. HARRY R. J. CONACHER, Vice-President, delivered a lecture entitled a “Sketch of Petroleum Geology.” Mr. Conacher referred to the early oil drillers as priding themselves in their practical skill and despising the guidance of the scientific geologist, and that only in recent years has the geology of petroleum become well enough understood to enable the oil driller to benefit from the guidance of the scientist. The first oil wells, opened in Pennsylvania fifty years ago, were the start of what was now a gigantic industry. A rough guide in the early days in districts known to be oil-bearing was given by the fact that the oil fields were longer than broad, and that they had a certain orientation. But this proved of no assistance when new fields had to be found. Hunt’s theory that anticlinal crests were the usual oil reservoirs had proved useful until the proper conditions had been determined. It is essential that a porous bed to act as reservoir be present with non-permeable beds above and below. The best containers are Sandstones, and the contained matter may be Gas, Oil, or Water. The Sandstone’s capacity depends on the size and shape of the grains, and on the presence of Cement. Large grains give good storage spaces, and conversely. Limestone, with abundant cracks, are very favourable, but Shales are less satisfactory unless fissured. Oolitic limestones are good, and igneous rocks, if fissured, occasionally act as storages. Besides storage beds, there must be material suitable for conversion to petroleum. The theories that explained the mineral Hydrocarbons as due to the action of water on metallic Carbides had now been given up. It was now recognised that the Petroleum was due to the decomposition of vegetable matter, and also to some extent animal matter. It was also now recognised that the anticline theory did not fit every case. Some of the greatest wells were in mid-continental states, with strata almost horizontal. Some gushers occurred on the flanks of anticlines. In America attempts had been made to locate lenticular sandbanks at great depths which acted as storehouses of oil. In Texas drilling had been done on the tops of domes of salt, the drilling in certain cases being carried to great depths. In Mexico various great flows for a short time had been obtained from highly fissured limestone, whereas in sand there was a steady flow for a long time. The meaning of the association of Brine and Petroleum was not yet understood. The oil on the surface of the Brine was probably pressed up, and the coming of Brine indicated approaching exhaustion. In general only a fraction of the oil is recoverable. The lecture concluded with a reference to the mining of oil sands for extraction of Petroleum in Alsace.
See below (Session 88) for further information on Mr H.R.J. Conacher, who gave the above lecture.
Extracts from the Proceedings of 1945-1946 (Session 88)
The President (Benjamin H. Barrett) referred to the Society’s loss by death of Mr. H. R. J. Conacher.
An obituary of Mr Conacher (which was later published in the Transactions (Vol. 21, pp. 154-155), and part of which is quoted below) was then read to the meeting by Dr Murray Macgregor, who had composed the tribute.
Mr. H. R. J. Conacher, who died suddenly on April 12th, 1945, at the age of 60, had a long and close association with the Geological Society of Glasgow. He joined it as an Associate Member in 1911, became a Member in 1912, and was enrolled as a Life Member in 1916. For a number of years, 1913-1916, he acted as Joint-Honorary Secretary, combining this post with that of Joint-Editor of the Transactions. He was elected a Vice-President in 1920.
Mr. Conacher entered the service of the Pumpherston Oil Company in 1899 and was early attracted to the study of the geological aspects of the Lothians’ oil-shales. He studied geology under the late Professor J. W. Gregory and in 1913 began the series of researches which he carried out over a number of years on the microscopic structure of shales, torbanites and cannels. He accompanied Sir William Fraser (now Chairman of the Anglo-Iranian Oil Company) during the 1914-1918 war as confidential secretary for the meetings of the Inter-Allied Petroleum Specification Commission. Later, he visited America to investigate and report on the oil-shale deposits of Colorado and Utah, and in 1935 was sent to Australia to prepare a report for the Commonwealth Government on Australian oil-shales. He took the opportunity of this latter journey to visit the chief centres of the Anglo-Iranian Company’s operations in Iran. In addition to possessing an intimate knowledge of the oil-shale fields of Scotland, he had a wide experience of shale-fields abroad and of the oil industry generally. He was also a recognised authority on the history of shale mining in this country, and his contribution on the “History of the Scottish Oil-Shale Industry ” to the third edition of the Geological Survey memoir on “The Oil-Shales of the Lothians ” (1927, pp. 240-265) was a masterly summary of the subject.
This was a Members’ Night, which included the following presentation:
Mr. R. H. S. Robertson spoke on “Fuller’s Earth in Scotland.” He pointed out that there is no Fuller’s Earth Industry in Scotland at the present time although it was worked in the past. In England it has been worked continuously for 1600 years. He referred to 14 occurrences of Fuller’s Earth in Scotland that he had traced in the literature and he considered that those at Elgin, Dunning and Maxton (Roxburghshire) would be worth investigating. Further investigations of their quality might lead to modern applications of Fuller’s Earth in Scotland.
Mr. Barrett (the President of the Society) introduced the speaker of the evening, Professor Arthur Holmes, D.Sc, F.R.S., and asked him to deliver his address on “The Construction of a Geological Time-Scale.”
The introduction of Professor Holmes’ address is reproduced below; the full text can be found in the Transactions, Vol. 21, pp. 117-152.
To measure geological time with reasonable accuracy the first essential is the recognition of a natural process which, operating at a known rate from a defined starting point, brings about measurable results either periodically or progressively. The establishment of an exact chronology by counting correlated sequences of the varves deposited during the last 15,000 years is a perfect example of the application of a periodic process, the period in this case being the year. The dating of a uranium-bearing mineral by determining the lead-isotopes generated within it during its life-history illustrates the use of a progressive process, the process in this case being spontaneous atomic disintegration. For the successful application of a method based on a progressive process, it is necessary to know:
The accumulation in minerals of the end-products of radioactive decay constitutes the only progressive process so far recognised in which these conditions are satisfactorily fulfilled over the whole range of geological time. The traditional geological methods, on the other hand, involve a complex of processes—denudation, deposition and diastrophism —so highly variable in space and time that they can be used as an hour-glass only in specially favourable circumstances covering relatively short periods. Samuel Haughton (1878, p. 268) introduced the celebrated principle that “the proper relative measure of geological periods is the maximum thickness of the strata formed during these periods.” As stated in this way, the principle implies that the average rate of accumulation, measured in terms of maximum thickness, has remained uniform during all the periods considered. Rigid uniformitarianism of this kind cannot be demonstrated, and, as we shall see later, there is conclusive evidence that the effective rate of accumulation has actually increased since Cambrian times. Several considerations require to be borne in mind in interpreting the significance of maximum thicknesses. It is important to realise that rate of vertical accumulation is by no means the same as rate of deposition. Most of the strata that build up the thickest accumulations are of shallow-water facies, and, as such, they are liable to be full of innumerable ‘gaps’ representing intervals of erosion and transport by bottom-currents at times when the depth of water was insufficient to ensure uninterrupted sedimentation. The resulting imperfection of what may be an apparently continuous record has been ably demonstrated by Barrell (1917, p. 796) in a masterly paper which is one of the classics of our subject. A maximum thickness thus represents a balance between income and loss at that particular place. Rate of deposition refers to the total income whereas rate of accumulation refers only to the balance. The balance is eventually controlled by the space made available for thick accumulations by earth movements, the latter being generally of the kind responsible for geosynclines. Hence it follows that maximum thicknesses are in reality measures of crustal depression. Since we cannot assume that rates of crustal depression have necessarily been the same in every orogenic cycle, Haughton’s principle should be limited to some such statement as the following: “The time elapsed since the end of any geological period is a function of the sum of the maximum thicknesses accumulated during all the subsequent periods” (See Table II and page 143). To determine the nature of the function it is obvious that some independent measure of time is essential. The purpose of this paper is to revise the chief age determinations from the Cambrian to the Tertiary, with a view to building up a time-scale and elucidating the relation between time and maximum thicknesses.
In the minutes of the meeting held on December 12, 1946 (Session 89) it is recorded that Professor Arthur Holmes, D.Sc., F.R.S. was elected to membership of the society; however, in the published membership list, his name appears in the list of life members rather than of ordinary members.
Extracts from the Proceedings for 1970-1971 (Session 113)
Professor W.J. McCallien, University of the Gold Coast (Ghana) delivered a lecture entitled ‘Some illustrations of Ghanaian rock structures’.
Sedimentary structures occur in Upper Palaeozoic rocks outcropping at intervals along the coast of Ghana from Accra westwards to beyond Takoradi. These varied and abundant structures were formed during and immediately after the accumulation of sediments in the shallow waters of the ancient seaway that separated the coast of the Gulf of Guinea from the shore of South America more than 300 million years ago. They occur essentially in sandstones and shales and point to a time when the sea floor of the region seems to have been very unstable and possibly affected by earthquakes.
William John McCallien (1902-1981) came from Tarbert in Argyll; after gaining his BSc in geology from Glasgow University in 1923, he joined the staff of the Geology Department. He was elected a member of the Geological Society of Glasgow in 1924, and in several talks that he gave on lecture nights over the next two decades, society members were able to learn about the results of his extensive research in Scotland and Ireland. In 1938 he was awarded the Neill Prize from the Royal Society of Edinburgh. In 1943 he was sent by the British Government to Turkey, where he eventually became Professor of Geology at Ankara and then Istanbul Universities. He moved in 1950 to Accra, where he remained until he retired in 1965; he then returned to Scotland, and he and his wife Catherine (also a Glasgow geology graduate) settled in Helensburgh.
Professor McCallien was elected an Honorary Member of the Geological Society of Glasgow in May, 1971, seven months after giving the above lecture.
Dr. A.C. McLean delivered his Presidential Address on ‘The western edge of Scotland’.
The geological history and structure of western Scotland can be expected to reflect the origin and development of the adjacent parts of the Atlantic Ocean. Investigations carried out in the 1960s provide evidence of ocean-floor spreading from the Mid-Atlantic Ridge since early Tertiary times. The strip of oceanic crust to the west of the Rockall Plateau is 58 million years old, and spreading has taken place at 1-2 cm. per year. The Rockall Plateau is composed of continental crust with sedimentary basins and Tertiary igneous centres. The Rockall Trough consists of oceanic crust with a thick cover of sediments, but lacks the magnetic strip anomalies of the oceanic areas to the west. It may be oceanic crust that formed during the geomagnetically stable Kiaman Interval (Permian-Triassic) or the remnants of an even older proto-Atlantic.
Tertiary igneous activity at the western edge of Scotland is coincident with the initiation of the Lower Tertiary phase of ocean-floor spreading. It also triggered off further marked subsistence in the southern Irish Sea basin, and the easterly tilt of Scotland is also probably related. Deep Mesozoic fault-bounded troughs, found on the Scottish shelf, may have been produced by stresses associated with earlier spreading that formed the Rockall Trough. Their distribution to the south of Scotland, however, suggests that they are not related in a simple direct way to the continental margin, but are part of a structure comparable to the Rhine Graben and its northerly continuation, and that it converges at a low angle with the continental edge on the western Scottish shelf. Stresses associated with the developing margin may have triggered off fault movements and igneous activity within an older structural zone. Carboniferous events in S.W. Ayrshire and the Firth of Clyde might, like the early Tertiary events, be associated with initiation of a phase of ocean-floor spreading.
Adam McLean PhD (1926-1983) graduated in 1948 with a degree in Geology from the University of Glasgow. After a career in industry, he returned to the Geology Department in 1954, specialising in geophysics to pursue extensive research in the west of Scotland and the Midland Valley. Dr McLean served as President of the Geological Society of Glasgow from 1967 until 1970.
Further information about the life and work of Dr McLean can be found in his obituary, which was published in Proceedings of the Geological Society of Glasgow for Sessions 124-125 (1982-1983), pages 8-10.
Extracts from the Proceedings for 1995-1996 (Session 138)
Session 138 started with “Constraints on Rapid Rates of Metamorphism in the North-West Himalaya” by Dr. Peter Treloar, (Department of Earth Sciences, Oxford). Dr. Treloar looked at the relationship between deformation and metamorphism in the North-West Himalaya. He gave us a detailed explanation of how the dissipative heating associated with friction permitted the attainment of high temperature and rapid metamorphism in the Indian Plateau within 10my of collision.
After the business [of the AGM] was conducted, the Social Evening started off with a geological quiz based on musical themes. Two teams competed to identify the geological connection in a number of musical items. Jim MacDonald was not able to be present in person, so he had recorded the musical themes – all played by himself on his clarinet.
Dr. Adrian Lister (University College, London) gave us a very interesting and entertaining talk entitled “The Natural History of the Mammoth”. This is one of the best known extinct species of mammal. A lot of detail has been preserved in the frozen mammoths found in Siberia. The woolly mammoth evolved from an African ancestor and appeared in Siberia at the start of the Ice Age. Their food was mainly grasses, mosses, ferns and small shrubs; they had only four teeth, but there were six sets of them – replaced from the back of the jaw, and each set bigger than the previous one. Their extinction came 10,000 – 12,000 years ago, possibly by a combination of climate change leading to a change in vegetation, and overhunting by the growing human population. Mammoth bone huts have been discovered in Siberia – one with the remains of 96 mammoths in the one hut – were they collected or killed?