Extracts from the Proceedings for 1869-1870 (Session 12)
Mr. J. WALLACE YOUNG read a paper “On the application of the Microscope to the examination of Rock Structure and Composition.” The author stated that although a mineral or rock might appear to the naked eye quite amorphous, yet when sections were prepared and examined by the aid of the microscope they presented a well-defined crystalline structure. By this method geologists would be enabled to distinguish rocks of igneous from those of sedimentary origin, or, as it sometimes happened, rocks originally sedimentary, which through metamorphism by water or atmospheric changes have had crystals developed in their mass. According to competent observers all volcanic products are crystalline; even lava, taken from a flowing stream and quickly cooled, shows this structure when submitted to the microscope. The geological description of a rock or mineral, therefore, is but half done without a microscopical and chemical examination. In illustration of his paper Mr. Young exhibited sections of basalt, greenstone, claystone, pitchstone, slate, limestone, lava, and various other rocks.
Mr. D. CORSE GLEN read a paper on the “Zeolites which occur in the Trap Rocks in the neighbourhood of Glasgow,” illustrated by a large collection of these interesting minerals from the author’s cabinet, consisting chiefly of Analcime, Natrolite, Stilbite, Heulandite, Chabasite, Laumonite, Thomsonite, Prehnite, etc. These minerals are all aluminous hydro-silicates, and their analysis has found them to consist chiefly of silica, alumina, lime, soda, potash, and water. They are found most plentifully in the trap rocks at Bowling, Kilpatrick, Port-Glasgow, Kilmalcolm, Fereneze, and Gleniffer hills. Several of them were first discovered in these districts, and named in honour of local mineralogists; Thomsonite, after the late Thomas Thomson, Professor of Chemistry in the University: Edingtonite, discovered by the late Thomas Edington, of the Phoenix Iron Works, near Kilpatrick, in 1823, and Greenockite, after Lord Greenock, now Earl Cathcart, who first found this rare and beautiful mineral in the Bishopton Tunnel in 1842. (The Bishopton Tunnel was part of the Glasgow, Paisley and Greenock Railway, an early Scottish railway which opened in 1841.) Some of the Analcimes and Prehnites which occur in the trap of Boylestone quarry, near Barrhead, are coloured by the copper which exists in a native state in the same rock, some examples of which were exhibited. Several specimens of the rare and valuable Greenockite were shown, which, although only about one-tenth of an inch across, are well formed and typical crystals. It is a sulphuret of the metal Cadmium, has a beautiful yellow lustre, and is pyramidal in form. This mineral has not been found anywhere except in the trap at Bishopton, the only known specimens having been obtained during the cutting of the tunnel, and from its great rarity is much prized by mineralogists, £20 having been paid for good crystals. An interesting specimen of Thomsonite from Magdala was exhibited, obtained by a soldier during the late Abyssinian war. (The Abyssinian war, which began in December 1867, ended when the Fortress of Magdala, or Maqdala, was captured by the British in April 1868.)
Extracts from the Proceedings for 1894-1895 (Session 37)
From the Report of the Council for 1893-1894. With the spread of photography and the facility it gives for the preparation of slides, the use of the lantern has become so general and so useful for the purpose of illustrating papers and lectures that it is a question whether the time has not now arrived when the Society should, like many others, possess a lantern of its own, so that on any evening the apparatus might be at hand for the exhibition of photographs taken by members.
Mr. JOHN SMITH exhibited a number of specimens, including:
Antimony Ore (Sulphuret of Antimony) from the brow of Hare Hill, New Cumnock. This hill rises to a height of 1950 feet, and the antimony mine is situated 300 or 400 feet below the summit, and at its mouth a large quantity of the ore is still lying. If we are to judge from this material the ore appears to be contained in a quartz vein of particular toughness and of a dirty-white colour. Through the quartz there are long slender prisms and minute particles of ore. In fact the ore appears to have mostly formed in long prisms, which appear as a rule to radiate from a point, and are of a bright silvery colour. The inter-spaces between the prisms are sometimes filled up with more amorphous-looking ore, but sometimes with a honey-coloured quartz. The prisms of sulphuret of antimony have in some cases been dissolved out from amongst the quartz, leaving hollow spaces; and occasionally the antimony only has been dissolved out, leaving the sulphur behind, partially filling the cavities. Antimony is used in medicine, also with lead forming an alloy from which type metal is made.
Further information on the history of antimony and its uses can be found on the Royal Society of Chemistry’s website.
Mr. JOHN SMITH exhibited a number of specimens, including:
Diatom and Sponge Spicule Deposit from Loch Doon, Ayrshire. About a hundred years ago the Loch was lowered by a mine being driven through the greywacke rock at the head of Glen Ness, and amongst other things exposed was a deposit which contained diatoms and sponge spicules, under a bed of peat. In the upper part of the bed the diatoms appear to have been destroyed by the iron which pervades it, though the sponge remains are abundant. The lower, and light-coloured, portion of the bed is a nearly pure mass of diatoms and spicules in splendid preservation. As it can only be reached when the water is very low the thickness has not been ascertained. When first laid bare a lot of it was used by neighbouring farmers as marl, and the inhabitants also soon found out that it makes a capital polishing material for metal-work.
Fine Gravel from the top of Ardeer blown sand-hills. Some of the quartz pebbles are 1/4-inch long, and flint chips, blown up from the implement-bearing gravelly hollows to the west, are nearly 1/2-inch long. That the action of the wind could raise these small heavy masses to such a height is wonderful. The Permian red sandstones of Mauchline, now so much used as building-stone, contain layers of gravel very similar in appearance to the above, and appear to have been formed from desert-blown sand.
Mr. W. H. G. CAMPBELL DICKSON exhibited specimens of Fulgurites, tubes formed by the passage of lightning through sand, from Witsand, Hill District, Griqualand, South Africa, and made some interesting remarks upon them. Mr. Joseph Sommerville said that, though an old member of the Society, he did not remember such forms having ever been shown at any of the meetings, and Dr. Young expressed himself to the same effect. Mr. John Smith said he had frequently examined the Ardeer sand-hills, and other likely localities, after thunderstorms, in the hope of finding similar forms, but as yet without coming across the slightest traces of them.
Extracts from the Proceedings for 1919-1920 (Session 62)
Mr. JAMES NEILSON read from the Glasgow Herald of 8th October, 1919, the notice of the death of Miss Miller, daughter of Hugh Miller. Mr. Neilson drew attention to this as an interesting link with the memory of the great Scottish geologist.
Dr. GREGORY, F.R.S., thereafter gave a lecture on the “Rift Valleys of Africa.” Dr. Gregory, who had recently returned from East Africa, where he revisited many of the scenes of earlier exploration, pointed out the difference between a valley formed by erosion and one formed by step faulting. The Jordan valley is a fine example of such on a grand scale, and from their resemblance to the well-known deep cracks or rifts which are a feature of the surface of the moon, Dr. Gregory has named such valleys rift valleys. By means of a series of photographs and maps shown by the lantern, the lecturer gave a detailed description of the features of the great earthquake rifts that extend continuously from the Jordan valley down to the Red Sea, and end at the south of Tanganyika. The abruptness of the sides of parts of these rifts as well as the step faulting was well shown by the slides, and the lecturer explained the waterlessness of parts of the country as due to this drainage.
Professor GRENVILLE COLE, who took part in the discussion, suggested that these rifts had probably been formed rapidly enough to be catastrophic. Mr. STARK, referring to Dr. Gregory’s remarks on the glaciation of many parts of equatorial Africa, asked the lecturer how this was reconciled with the view that the glacial period in the North Hemisphere was accompanied by a warm period in the south.
Dr. GREGORY, in reply, referred to the summit of Mount Kenia on the Equator being above the snow line, and that the extended ice cap of the glacial period caused such a disturbance of the prevailing winds as to lead to heavy precipitation of snow on the higher parts of Africa. In reply to Professor Cole, he gave some facts observed by the engineers of the Uganda Railway as to the instability of the floors of these great valleys.
Professor Grenville Cole (1859-1924) was known as “the cycling geologist” and published accounts of his cycling expeditions in Europe and Ireland. He was Professor of Geology and Mineralogy in Dublin from 1890, and Director of the Geological Survey of Ireland from 1905; he was President of the Geographical Association from 1919 to 1920; he also served as external examiner at times for several universities, including Glasgow. There is unfortunately no record in the Proceedings of the reason for his visit to Glasgow in 1919.
Mr. G. V. WILSON, H.M. Survey, read a paper on “Some Scottish Ore Deposits.” Mr. Wilson discussed chiefly the occurrence of Lead Ore, and especially in the district of Leadhills. The earliest reference goes back as far as 1120, and Sir David Lindsay gave a charter to the monks of Wanlochhead about 1350. From that time the output of lead increased until in 1500-1600 the Leadhills were producing lead in considerable quantity, £100,000 worth having been recorded in three months. The ore worked at first was scattered in the moraine drift, where streams had washed away the finer matter. It was not until later that the veins were discovered. These originate in the igneous rocks, and do not travel far into the country rock. The district is cut by numerous parallel Felsite dykes, indicating a large reservoir of igneous rock. Mr. Wilson discussed at some length the different views as to the formation of the veins. The paper was illustrated by a large number of beautiful mineral specimens exhibited by Mr. Henderson and also by lantern slides.
Mr. G. W. TYRRELL delivered a lecture entitled “Recent Developments in Geology of Spitsbergen.” After a brief account of the history of our knowledge of Spitsbergen, the discovery of which is generally attributed to the Dutch in 1596, and to whom the name Spitsbergen is due, the lecturer gave an account of the geology of the island, or rather archipelago. Whalers and trappers were early attracted to the island and its adjoining seas, but the present attraction of the country is its mineral wealth. The first coal-bed was discovered 300 years ago, and a British company began mining in 1904, near the mouth of Advent Bay, and Longyear City, opposite to the British mine, is American property, acquired in 1904.
The main geological features are the block-faulted mountains showing horizontal strata, and most of the systems are represented. In the western mountains no fossils have yet been found, but in Bear Island fossils of Silurian age have been dug. Broadly speaking, there are two geological divisions. Along the west and north lie old rocks thrown into folded mountains which show the sharp weathered peaks which give the island its name. (“Spitzbergen”, from the Dutch, means “pointed mountains”.) The eastern part shows newer rocks faulted into the block systems already mentioned. The old rocks contain ores, and the later rocks contain coal. The coal belongs to three age — Carboniferous, Jurassic, and Tertiary. The latter coal is of excellent quality, and occurs in several seams from 31/2 to 7 feet thick.
Mr. Tyrrell described in considerable detail the main features of the rocks and their fossils, and in conclusion gave in a series of stages the main phases in the geological story of Spitsbergen, enabling his audience to watch the growth of the island from the period when sands and clays were laid down on an Archaen foundation to the last uplift which gave the present raised beaches, fjords, and crossed faults.
Dr. GREGORY and Mr. WORDIE took part in the discussion, which turned chiefly on climatic changes and the origin of the Spitsbergen coal, which Professor Gregory thought might be due to accumulated drift wood, such as is seen along the present shores of the island.
Later in 1920, James Wordie took part in the last expedition that William Speirs Bruce made to Spitsbergen.
James (later Sir James) Wordie (1889-1962) was born in Partick. In 1910, he graduated B.Sc. in geology from Glasgow University, and in 1912 he gained an M.A. from Cambridge University, where he subsequently had a long and successful academic career. He joined the Geological Society of Glasgow in 1912, and remained a member for the rest of his life. Among his many achievements were nine polar expeditions, the first of which was the Trans-Antarctic Expedition of 1914-17, led by Ernest Shackleton; Wordie was on the scientific staff of the Endeavour, and his diary records that “The worst part of the whole expedition was the open boat journey to Elephant Island.”
For an account of the venues and times of meetings of the Society during the war years, see the note concerning the meeting held on October 9, 1943; this can be found in the extracts from the Proceedings for Session 86.
Extracts from the Proceedings of 1944-1945 (Session 87)
Dr. A. Muir of the Macaulay Institute for Soil Research delivered a lecture on “Some Aspects of Soil Geology.”
Dr. Muir said that up to the latter part of the nineteenth century agricultural chemists dealt with the soil but not with the sub-soil. Soil surveys carried out in Russia laid the foundation of Pedology, a subject which is not just a branch of geology or of agricultural chemistry. The link between soil science and geology is the soil parent material which under differing conditions of climate and topography gives rise to different soil types. For local conditions a classification of soils on the basis of lithology of the parent material is necessary since so many soil properties are directly due to its physical and chemical properties. It is being found, for example, that many crop and animal diseases are due to deficiency or excess of certain elements and a knowledge of their distribution in rocks and soils is becoming increasingly important.
Dr. W. Q. Kennedy gave a lantern demonstration entitled “The Production and Processing of Scottish Mica.” He said that the production of mica in Scotland is a purely war-time industry. The deposit described is in Knoydart, at a height of 2,000 ft. on the north side of Loch Nevis, where the mica occurs in “books” in pegmatite. Lantern slides were shown to illustrate the quarrying of the pegmatite, the collecting of the mica, and the splitting, cutting, grading and packing of the mica plates. Specimens of cut mica were exhibited.
Further information on this topic can be found on the BGS’s Earthwise website.
Extracts from the Proceedings for 1969-1970 (Session 112)
Dr. C.D. Gribble (University of Glasgow) delivered a lecture entitled “Diamonds: prospecting and mining in Tanzania”.
The speaker described the programme of prospecting in which he had taken part. Kimberlites are emplaced mainly within areas occupied by granite shields. During three to four months a team covers an area in the region of 3,000 square miles, sampling soils by use of a grid method in flat ground, sampling river sediments in undulating country, or by the use of barrages in hilly country with abundant water supply. Samples containing ilmenite, garnet and diopside indicate the presence of kimberlite and lead to more detailed search for diamonds. The chances of finding a diamond are very remote, however; only one part in 500 million parts of sample is composed of diamond. The speaker went on to discuss the origin of kimberlite pipes and the diamonds in them.
Dr S.E. Calvert (University of Edinburgh) delivered a lecture entitled “Mineral resources of the sea floor”.
Marine mineral resources have attracted considerable attention in recent years. Oil, gas and heavy minerals are at present being recovered from relatively shallow water, but the mineral storehouse of the future is in deeper water.
Phosphorite deposits, found on many continental shelves, usually on the eastern sides of the oceans, although perhaps not forming at the present day, may have done so under different conditions in the recent past. In deeper water, manganese nodules cover large areas of the ocean floor. Compositions are variable but they generally contain relatively high concentrations of nickel, copper, cobalt, lead, molybdenum and zinc as well as manganese and iron. The total tonnage of metals in the nodules of the deep seas is much larger than commercial landbased reserves.
Extracts from the Proceedings for 1994-1995 (Session 137)
Session 137 started with a very interesting and informative talk by Dr. Robert Muir-Wood (EQE International Limited, Warrington) on “Tectonics versus Glacial Rebound as the Cause of British Earthquakes”. There are more earthquakes in Scotland than in the rest of the British Isles, and this gave rise in the last century to the building of the little ‘earthquake house’ in Comrie, Perthshire, due to the amazing frequency of the occurrence of the ‘quakes in that area, albeit rather small ones. Those earthquakes occurring in England and Wales are on the whole larger; some areas, however, notably the whole of Ireland, are almost devoid of seismicity. Dr. Muir-Wood discussed the possible causes of this activity. Considerable variety and complexity of tectonic activity occurred around and through Britain during the Tertiary, when it lay in a broad sub-plate boundary shear-zone connecting the Alpine and North Atlantic plate boundaries. A major episode of compressional deformation is also found in north-west Britain accompanying the re-invigoration of the Iceland hot spot in the Miocene. However, comparative studies in other regions of post-glacial rebound, including Fennoscandia and North America, show strong parallels with Britain and also provide an explanation for the Irish seismic paradox.
Leader: Dr. A.J. Hall, University of Glasgow
Report by Dr. Ben Browne
On a bright spring morning, twenty-six members assembled by the old mill at the foot of Alva Glen (NS 885975) on the line of the Ochil Fault.
A walk up Alva Glen alongside the old iron pipe which supplied the mill demonstrated good exposures of a coarse agglomerate of Devonian lavas intruded by a Permocarboniferous dolerite sill, an association possibly giving rise to hydrothermal systems and the mineralisation of Silver Glen. The story though is complicated by the occurrence of mineralisation of Tertiary age in the same general area.
Returning from Alva Glen, a traverse eastwards across a green hillside brought us to the wooded Silver Glen (at NS 892974) so named in memory of a great bonanza find of silver ore worked out in the eighteenth century.
Working upstream on the eastern bank of the burn, traces of old workings were very evident, and on recrossing the burn just above a fall, we came across none other than Dr. Stephen Moreton sifting spoil tips for silver. Dr. Moreton has made a great study of this mine and its history, and has revised previous ideas on the location of the main mine. We were most fortunate to be treated to a discourse on the historical detail eagerly awaited in Dr. Moreton’s pending publication.
The mine was opened in 1714 on the land of Sir John Erskine. The ore was assayed by none less than Sir Isaac Newton as Master of the Mint and found to be good. Soon the greatest bonanza find of silver ever known to be found in the British Isles yielded £40-50,000 in fourteen weeks, without counting the ore stolen by miners. Sir John became incredibly rich and improved his estates, but he supported the Jacobite rebellion and so was exiled to France. It seems he was able to buy his reprieve with a promise to open his last mine. The venture proved disappointing and the bonanza was never repeated. The next to try his luck was Charles Erskine in 1759. He found not silver but cobalt ore “the colour of peach blossom”. This ore was used to make a blue glaze in the Prestonpans pottery.
On picking over Dr. Moreton’s discarded siftings, we were able to find grains of cobalt ore and pan out flakes of silver, so were were able to go home happier and wiser, if not greatly richer.