the British Isles of the members of the Carboniferous system, and divides the whole into successive stages from A to G, thus: Middle Localities. Lancashire, N. Wales. Lower ditto, or Gannister Beds. England, Wales, Ireland. Upper Coal-measures. F. E. D. Millstone Grit. England, Scotland, Ireland. England, Lower Coalfield of Scot- England, Ireland, Calciferous These beds are then identified, both by position and palæontological remains, over the whole area, and lead to some important results. Rejecting the evidence of fish- and plant-remains, which are inconclusive, the author finds that there is a strong paleontological distinction between stages E and F-the fauna of the one (E) being essentially marine, that of the other (F) essentially estuarine or freshwater. The lists of species have been extracted from the memoirs of the Geological Survey, the determination being those of the late Professor E. Forbes, Mr. Salter, and Mr. Baily. The author of this paper is responsible for the determination of the stratigraphical position of the beds from which the species have been obtained. He finds that there are about 53 species of marine genera in stage E (Gannister beds, or Lower Coal-measures)*, of which 33 come up from the Carboniferous limestone, but only 4 or 5 pass up into the overlying stage F (Middle Coalmeasures), indicating a strong palæontological break. Again, of 8 marine species found at rare intervals in stage F (Middle Coalmeasures), 4 are peculiar to this zone, and the remainder are common to it and stage E. The remaining species belong to the genera Anthracosia, Anthracomya, &c., which some authorities regard as of freshwater origin, others estuarine; they are probably either: these genera pass into stage G. These differences, together with some of a stratigraphical nature, between stages F and G on the one hand, and E, D, C on the other, are so striking that the author submitted that they should be recognized in the classification of the beds; and he proposed to establish a "Middle Carboniferous" division, to include all the stages from the Yoredale (C) to the Gannister (E) inclusive. This stage would be essentially marine; while the term "Upper Carboniferous" would be restricted to the stages F and G, which are shown to be estuarine or freshwater. The term Lower Carboniferous would remain as at present, to designate the Carboniferous Limestone and basal beds of the system, stages A and B. The author has reason to believe, from information supplied by Professor Roemer, of Breslau, that the marine stage E can be identified on the continent, both in Belgium and Germany a band with Goniatites and Aviculopecten occurring about 100 feet above the base of the Coal Measures, while, as we learn from Geinitz, the mollusks of the Coal-formation generally belong to the genus Unio (Anthracosia), so that this remarkable division, with its marine fauna, has had a range as wide as the British Isles and Western Europe, and marks the upward limit of the essentially marine conditions of the Carboniferous system. On a Deep Boring for Coal at Scarle, near Lincoln. Professor EDWARD HULL, F.R.S. Communicated by This boring was undertaken about two years ago by a small company of Lincolnshire gentlemen under the advice of Mr. J. T. Boot, mining engineer, of Mansfield, from whom I have received information and specimens constantly during the operations, besides having visited the locality in June 1875. The works have been carried out by the Diamond Rock-boring Company, and specimens of the cores were laid on the table. * They have since been considerably added to.--February 1877. The total depth attained up to this time is 2035 feet. The boring commences n the Lower Lias at a spot about 6 miles south-west of the city of Lincoln, and after traversing the Lias, Rhætic, Keuper, and Bunter beds, the Upper Permian and Lower Permian, it entered the Carboniferous formation at a depth of 1901 feet, the remainder of the section being in Carboniferous strata. The general succession is as follows: Alluvium. Lower Lias Clay Rhætic Beds ? Depth. Thickness. Lower Sandstone The temperature at 2000 feet was 79° F., taken with one of Negretti's thermometers supplied by Professor Everett, of Belfast. At a depth of 917 feet a strong feeder of water was encountered in the Lower Keuper Sandstone, and a still stronger at 1250 in the Bunter Sandstone, when the water rose 4 feet above the ground. This water unquestionably percolates underground from a distance of 10 or 12 miles, where the beds crop out. This boring is exceedingly interesting as giving the depth of the Carboniferous rocks so far from the borders of the Nottinghamshire coal-field, and as giving the thickness of the overlying formations; but it has (unfortunately for the spirited gentlemen who have undertaken it) not as yet produced any satisfactory results. The Carboniferous beds are of so peculiar a character that I hesitate to attempt to identify them with any particular division of the Carboniferous system. Meanwhile, as the boring is still being prosecuted, it is hoped that specimens of a more definite nature may be brought up. On Tertiary Basalt-rock Dykes in Scotland. By R. L. JACK, F.G.S. On some New Minerals, and on Doubly-refracting Garnets. The writer exhibited specimens of the new mineral which he terms melanophlagite, in consequence of its peculiarity of becoming black when heated before the blowpipe. It occurs in very small cubic crystals, of pale brown colour, seated on little scalenohedra of calcite, which are associated with the sulphur and celestine of Girgenti, in Sicily. According to analyses, melanophlagite contains 86-29 per cent. of silica, 7.2 of sulphuric acid, or some acid of the thionic series not yet determined, 2.8 of strontia, 2.86 of water, and small quantities of alumina and ferric oxide. Dr. Von Lasaulx also exhibited specimens of his new species aerinite, and several microscopic sections of garnets which exhibited double refraction. He entered into an explanation of the causes of such optical irregularities in monometric crystals, and referred them partly to the effects of tension, partly to chemical alteration, and partly to complexity of structure, due to alternations of isotropic and anisotropic minerals. Thus the variety of garnet called colophonite appears to be a mixture of true garnet and idocrase; hence, whilst one part exhibits single refraction, another part shows double refraction. On the Changes affecting the Southern Extension of the Lowest Carboniferous Rocks. By G. A. LEBOUR, F.G.S. In Scotland the lowest division of the Carboniferous series consists of the rocks called "the Calciferous Sandstones" by Maclaren, and usually known in the north of England as "Tuedian." Prof. Geikie has shown that the lower limit of these rocks merges insensibly into the upper portion of the Old Red Sandstone series. In England their upper limit seems to be equally indefinite, and runs in a kind of lateral dovetailing into the lower beds of the Carboniferous Limestone series or "Bernician." It is this merging of Tuedian into Bernician which forms the subject of the paper. Some remarks as to the terminology of the series followed, and also a short account of the higher divisions of the Carboniferous as represented in the north of England, pointing out especially that the mode of deposition there was nearly of the same character from the base of the Millstone Grit to the Old Red series, a slight and very gradual change from brackish to purely marine conditions being the only one of a sufficiently marked and important character to be taken into account. The author admits but two Carboniferous divisions-the Upper, consisting of Coal-measures, Gannister beds, and Millstone-grit; and the Lower, including the Bernician or Carboniferous Limestone and the Tuedian or Calciferous Sandstones. On the Parallel Roads of Glen Roy. By J. MACFadzean. On the Parallel Roads of Glen Roy. By DAVID MILNE-HOME, LL.D. The object of the author in this paper was to notice the views of Dr. Tyndall given in a Lecture on Glen Roy, delivered in the Royal Institution, London, on 21st June, 1876. The author thought that Dr. Tyndall had allowed to himself too short a time, viz. only two days, for an examination of the Lochaber district, as in that space it was impossible to see more than a tenth part of the things which should be examined for a solution of the Parallel Roads problem. Dr. Tyndall had apparently gone to the district with preconceived opinions in favour of the glacier theory to explain how the lakes had been confined. His knowledge of the Swiss glaciers eminently qualified him to see on the spot whatever could be urged in support of that view. But, after all, the result of Dr. Tyndall's inspection had only satisfied him that there was a "probability" of the correctness of the glacier theory, though a probability so great as in Dr. Tyndall's opinion to "amount to a practical demonstration of its truth." To pave the way for the adoption of the glacier theory of lake-barriers, Dr. Tyndall began his lecture by attempting to annihilate what seemed to him the only other explanation worthy of notice, viz. that first suggested by Sir Thos. Dick Lauder, and defended by Mr. Milne-Home, that the lakes were dammed by detrital blockage. He states that this explanation may with safety be "dismissed as incompetent to account for the present condition of Glens Gluoy and Roy." Dr. Tyndall, however, seems to have supposed that no better support could be given to the detrital theory except what was stated in Sir Thomas Lauder's paper, published about sixty years ago, ignoring altogether what had been advanced in support of the theory by later writes. He, for example, states that the detrital barriers were supposed by Sir Thomas Lauder to have been heaped up by "some unknown convulsion," a view which no one now suggests, and which Sir Thomas himself never entertained. What is stated in support of the detrital theory is, that a blockage existed at the mouths of the glens, created by the detritus, which then filled the valleys, and which reached even to the mountain tops at heights of nearly 2500 feet above the sea. Dr. Tyndall admits the abundance of detritus at these heights, and even allows that the Parallel Roads were formed on the detritus. Glen Collarig shows that the barrier there must have been only 700 or 800 yards in length and about 300 feet in height, as the lakes in that Glen must have been separated by a blockage of these dimensions. Dr. Tyndall alleges that all the glens on the south side of Glen Spean were filled with ice, whilst those on the north side were filled with water. But so far from there being evidence of these valleys being filled with ice, it appears that they also were occupied by lakes, the traces of which are still visible in old beach lines. Even if there had been glaciers in Glens Treig and N'Eoin, as suggested by Mr. Jameson, it would have been impossible for these glaciers to have protruded tongues long enough to have reached the places in Glens Roy and Collarig where barriers are required to have been. On High-level Terraces in Carron Valley, County of Linlithgow. By DAVID MILNE-HOME, LL.D. The river Carron runs into the Frith of Forth near Grangemouth. The principal tributary is the Bonny. The whole of that district situated to the east of the Kilsyth and Gargunnoch hills is covered with deep beds of gravel and sand. The sand occurs in beds, mostly stratified and generally horizontal. No marine fossils have been found in these drift-beds; but the great probability is that they are marine. The first set of terraces occur at a height of about 140 to 150 feet above the sea. Flats at that height occur on both sides of the valley some miles west of Falkirk; these flats slope towards the eastward, i. e. towards the sea, so that near Grangemouth they very little exceed 50 or 60 feet above the sea. Terraces at a height of from 140 to 150 feet occur also in the upper parts of the Carse of Stirling. The second set of terraces occurs only along the banks of the rivers, and is at a height in the Carron of about 35 feet, and in the Bonny of about 29 feet above the present course of these rivers. It is presumable that these haughs were formed when the Carron ran in a channel about 27 feet above its present level, and when the Bonny ran about 25 feet above its present level. The formation of these haughs indicates that the rivers had run permanently in channels at that height. The sea therefore, in sinking, had paused in the process, and had stood at a height of about 24 or 25 feet above the present level. This inference is confirmed by the fact of there being traces of an old sea-beach at about that height visible along the coast of the Frith of Forth. The pebbles in the gravel-beds of the district are generally fragments of the hard porphyry rocks of the Gargunnoch and Kilsyth hills, situated to the westward. They could have come from no other quarter. On the Bagshot Peat-Beds. By W. S. MITCHELL, LL.B. On Circinnate Vernation of Sphenopteris affinis from the Earliest Stage to Completion; and on the Discovery of Staphylopteris, a Genus new to British Rocks. By C. W. PEACH, A.L.S. The author stated that he had met with Sphenopteris affinis in the Carboniferous "blaes" (shales) of an oil-shale pit at West Calder, near Edinburgh, in circinnate vernation, and with it a curious form, apparently a Staphylopteris (?), new to British rocks. Several species of this new genus have been found in Carboniferous rocks by the officers of the Geological Survey of Illinois and Arkansas, in America; these are figured and described by Leo Lesquereux in the Geological Transactions of those States. The author stated that his differed from all these, and thus, until more is known about the British one, he had provisionally given it their generic name. On the Mountain Limestone of the West Coast of Sumatra. By Dr. F. RÖMER. On the Raised Beach on the Cumberland Coast, between Whitehaven and Bowness. By R. RUSSELL, C.E., F.G.S., and J. V. HOLMES, F.G.S., H.M. Geological Survey, England and Wales. On the coast of Cumberland, between Workington and Bowness, the remains of an old sea-beach can be most distinctly followed, and south from the former place there is abundant evidence to show that the elevation of the land marked by this raised beach affected the whole of this portion of the west coast of Cumberland. The characteristic appearance which the raised beach presents is a flat of greater or less width stretching inland-in some cases terminating at the base of a cliff, and in other instances bounded by a flat from 4 to 5 feet below the level of the surfacegravel of this old beach. North of Workington we have an example of the former case, and at Silloth an instance of the latter. The surface of this flat is covered with a number of ridges approximately parallel to the coast-line and to each other, and these ridges consist of sand and gravel partially covered at various places along the coast with blown sand. This ridgy appearance is seen to be exactly like that portion of the present beach lying between the levels of the highest spring- and the highest neap-tides, where small ridges of gravel are observed to be thrown up at the various different levels to which the tide flows in the interval between the two periods above referred to. Typical examples characteristic of littoral deposits are seen at Workington, Harrington, St. Bees, and at numerous places along the coast. The general resemblance between this upper terrace and the present beach, even in the absence of marine shells in the former, shows that the process of formation in both cases must have been the same. On the coast between Workington and Whitehaven it exists in small isolated patches, as at the north end of the ridge at Chapel Hill, at Harrington, at Parton, and at Whitehaven. From Workington northwards through Maryport to Brown Rigg the line of an old sea-cliff is for the most part very distinctly marked, at the base of which occurs a flat of from 40 chains to 2 chains in breadth; at Allonby this flat is bounded by a gravel or shingle ridge; while from Silloth north to Grune Point, and across Morecambe Bay, from Anthorn to the Solway Viaduct, the country on the east of the old beach consists of a loamy plain, several feet below the level of this beach, from 3 to 4 miles broad, and dotted here and there with a few patches of sand and gravel. The height of the raised beach is from 20 to 25 feet, rarely exceeding 30 feet above the present sea-level. However the base of the old sea-cliff from Oyster Bank to Totter Gill, north of Workington, is about 40 feet above mean sea-level, and there is no distinctive cliff marking a 25-feet beach; it would therefore seem that after the first upheaval the elevation continued to take place very gradually until 40 feet was attained, the beginning of the period of elevation being indicated by the level of the land at the base of this cliff, and its close by the present sea-level. A consideration of the evidence to be obtained from Roman camps and other remains along the coast seems to confirm the conclusion arrived at by Mr. MilneHome in regard to the latest elevation of the land on the Scotch coasts, viz. that it was prior to the Roman occupation of this country. Notes on the Drifts and Boulders of the upper part of the Valley of the Wharfe, Yorkshire. By Rev. E. SEWELL, M.A., F.G.S., F.R.G.S. It is evident that the Wharfe valley in many places must once have been filled up to a certain height with gravelly drift and boulder-clays, containing a very large quantity of Millstone-grit blocks, and that since then the river has excavated a channel in the drift to the depth, in many places, of at least 150 feet. |