Clay Slate Research Articles

Note on the Ogam and Latin Inscriptions from the Isle of Man, and a recently found Bilingual in Celtic and Latin

A brief account of the previously published Latin and Ogam inscriptions on the Isle of Man is accompanied by illustrations. The new discovery from Knoc y doonee, has the first example of a bilingual inscription in Ogam and in Roman capitals from the island. It is a large pillar of clay slate. The fact of the pillar having its edges dressed shows that this cannot be a monument of the earliest period; but the inflexions in the Celtic inscription and the plain capitals and whole character of the Latin one, are, with the forms of the names, in keeping with the idea that it may belong to the first half of the sixth century.

On the Chemical Composition of American Shales and Roofing Slates

IN the preceding paper the statemeut is made that the analyses of the green slates at Slatington, Calif., differ widely from those of any normal clay slates. So little attention is paid to the composition of sedimentary rocks, as compared with that of igneous rocks, that the truth of this statement may not be obvious to all readers. The present paper has been prepared partly for this reason, but more largely because a summary of our present knowledge of the subject seems desirable. Thirty-six analyses of American roofing slates have been compared and used in the preparation of an average. These analyses include all the published records noted by the writer in the course of an examination of the literature, together with several unpublished analyses obtained from the records of the chemical laboratory of the U. S. Geological Survey. The writer's acknowledgments are due to Dr. F. W. Clarke and Dr. W. F. Hillebrand for aid in this work. Geographical distribution of the slates.-The thirty-six analyses of slate discussed in this paper represent material from eleven states, representing twelve distinct slate-producing districts. While this geographic distribution is fairly representative of the present condition of the slate industry in the United States, it is by no means representative of the available supply of good material; for, of the twelve states from which analyses are on file, ten are states of the Atlantic seaboard, or closely adjacent thereto. Utah and California furnish the remaining analyses. This distribution is due to purely commercial causes, which have prevented the exploitation of equally good material located in other states, but without transportation facilities or markets. To this extent, therefore, the analyses are not as representative of a given type of material as one might wish. Geologic distribution of the slates.-Owing in large part to the geographic distribution of the analyses, the geologic distribution

Note on agate specimens from Monzie

Locality. These specimens were obtained from the Porphyrite formation, which for the most part divides the Lower Old Red Sandstone of the great centre valley of Scotland from the Clay Slate and Greywacké of the southern highlands. The exact locality of these agates is a small tributary of the Shaggie, on the left bank, and about three hundred yards north of the schoolhouse at Monzie. (See sketch map adjoining.) Proceeding up this stream from A towards B, as marked on the sketch, we find some interesting variations in the contents of the rock. Association. 1. At A a reef of Carytes runs for some yards on the left bank of the stream. I am inclined to think this reef persists probably as far as B, as I find there in the bed of the stream fragments of the mineral. 2. Further on just above the point where an old road (now disused) crosses the stream, we find amygdaloidal porphyrite. The rounded enclosures of this are mostly calcite, but here and there they are composed of red or blue chalcedony, and some of them are true agates. 3. Still further up the burn we reach the place where the specimens about to be described are found. 4. Then again, about the old road to Sma’ Glen, the rock is intersected by jasper veins. Common Characteristics. 1. Irregularity of shape—so markedly different from the rounded, oval, or flattened form of the common

Note on Altaite from Burma

By the kindness of Mr. A. H. Bromly, Manager of the Choukpazat Gold Mining Company's mines at Choukpazat, Wuntho, Upper Burma, I have received a few hand-samples of the veinstuff from these mines. The vein runs in clay slate or ehloritic slate, parallel apparently to the bedding, with a strike north-east to south-west, and a dip of 20° to 25° to the south. The veinstuff, to judge from the samples submitted to me, consists of white, somewhat saccharoidal quartz, with some calcspar, and contains iron pyrites, alsenieal pyrites, visible free gold (rather pale in colour and apparently rich in silver), and the mineral that forms the subject of the present note.

XXVIII. On a Glacial Mound in Glen Fruin, Dumbartonshire

Glen Fruin* is a quiet secluded glen, about 6 miles in length, extending in a north-westerly direction between Loch Lomond and the Gareloch, and opening off the neck of land which divides these lochs at between 200 and 300 feet above the sea. On the south-east it slopes towards Loch Lomond, of which the Fruin water is one of the principal affluents. On the west it is bounded by a range of hills 1000 to 1200 feet in height, which at the upper extremity, towards Garelochhead, subside into a col or pass of 600 or 700 feet. The upper part of the glen is composed of the mica and clay slates common to the Western Highlands. The lower part is formed of beds of the Calciferous Sandstone series, which have apparently been faulted down between the adjacent Old Red Sandstone and the older Silurian rocks. The huge boulder of mica-schist, resting on the sandstone, at Callendoun, near the mouth of the glen, about 200 feet above the sea (and measuring 28 × 18 × 10 feet), was brought under the notice of the Boulder Committee of the Royal Society of Edinburgh by Mr. R. L. Jack, when engaged on the Geological Survey of the district, and was afterwards visited by the Convener of the Committee, the late Dr. Milne-Home, and figured and described by him in one of the Committee's annual Reports. By some mistake, as we formerly pointed out, † either Mr. Jack, or the Convener in copying his This 250-word extract was created in the absence of an abstract

Relations of the Laurentian and Huronian Rocks north of Lake Huron

Research Article| January 01, 1892 Relations of the Laurentian and Huronian Rocks north of Lake Huron* Alfred E. Barlow Alfred E. Barlow Search for other works by this author on: GSW Google Scholar GSA Bulletin (1892) 4 (1): 313–332. https://doi.org/10.1130/GSAB-4-313 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Alfred E. Barlow; Relations of the Laurentian and Huronian Rocks north of Lake Huron. GSA Bulletin 1892;; 4 (1): 313–332. doi: https://doi.org/10.1130/GSAB-4-313 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Introduction.In this paper, which is a revision and extension of one published in the American Geologist of July, 1890, the writer proposes to bring forward some observations on the nature of the contact between the Huronian rocks of Lake Huron, described by Logan and Murray, and the Laurentian gneisses, which it is thought have an important bearing on the question of the origin and relative age of the latter.THE HURONIAN ROCKS.The rocks of the Huronian area to the north of Lake Huron are made up of a series of quartzites, graywackes, slate conglomerates, clay slates hydromica, chloritic, and hornblendic schists, greenstones and. some bands of cherty limestones or dolomites. Frequently these rocks show a pyroplastic origin, and tuffs and breccias are very commonly met with. The majority of the clay slates have the appearance of being very little altered, except in contact with the greenstone and other . . . This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

VII.—On a Glacial Mound in Glen Fruin, Dumbartonshire

Glen Fruin is a quiet secluded glen, about six miles in length, extending in a north-westerly direction between Lochlomond and the Gareloch, and opening off the neck of land which divides those lochs at between 200 and 300 feet above the sea. To the south-east, it slopes towards Lochlomond, of which the Fruin water is one of the principal affluents. On the west it is divided from the Gareloch by a range of hills 1000 or 1200 feet in height, which at its upper extremity subside into a col or pass of 600 or 700 feet. This upper part of the glen is composed of the mica and clay slates common to the Western Highlands. The lower part is formed of beds of the Calciferous Sandstone series, which have here been faulted down against the older formations.

1. Report of the Boulder Committee, with Remarks by the Convener

Between Crinan Bay on the north and the head of Loch Fyne on the south, there is a trough or hollow now occupied by the Crinan Canal. The highest point along this trough, is about 150 feet above the sea. A series of locks occur at this summit-level, to allow of the passage of vessels between the two sea-lochs.At the summit-level, the rocks form a sort of ridge across the valley, with smooth surfaces towards the north, and rough surfaces towards the south.On both sides of this rocky ridge, there are large boulders; on the north side, I counted between forty and fifty, on the south side, there are not more than two or three. The boulders are a syenitic gneiss; the rocks in situ, are shivery clay slate, nearly vertical, dipping steeply towards the south.

A Successful African Expedition

A Successful African Expedition

On the Geology of Anglesey

The rocks to which these notes chiefly refer were described by Prof Henslow under the heads of Quartz Rock, Chlorite-schist and Grauwacke, in a paper read before the Cambridge Philosophical Society in 1821. He evidently considered them to be distinguishable members of one group, drawing attention to the passage from the quartzite into the schists, and to the generally coinciding dip of the clay slate and schists, even where, as at Porth Corwg, there is a small discordancy between the two, caused by a fault. He points out that green slates and brecciated conglomerates occur in the upper part of the black-slate group; but he records no fossils from which the geological horizon of the beds described can be determined, and his sections do not give much more than the geographical succession of the rocks over the areas referred to in this paper. Prof. Ramsay (Mem. Geol. Surv. vol. iii. p. 175) describes the Cambrian and Silurian Rocks of Anglesey as in great part resembling those of Caernarvonshire. The Cambrian rocks, he further remarks, are, as a rule, highly metamorphic, like those in the promontory of Lleyn (Cambrian in his nomenclature includes only the Harlech group). The Silurian ( i. e. the Lingula-flags and all above them), he goes on to say, are also sometimes metamorphosed into mica-schists and gneiss, while in other places they are rich in Caradoc or Bala and Llandeilo fossils. Unfortunately the genera and species of the Graptolites are not recorded except from one locality mentioned in

On the age of the clay slates and grits of Poughkeepsie

On the age of the clay slates and grits of Poughkeepsie

Observations on the Miocene Beds of Greenland

‶We brought home—that is to say, my companion Mr Edward Whymper (brother of my old travelling friend Mr F. Whymper, a Foreign Member of your Society) and myself, under my direction—an immense load of specimens—leaves, fruits, twigs, and possibly a cone of some coniferous tree—principally from Atanakerdluk (lat. 70° 02′ 30″ N.), Kudlesaet, and Ounartok, all localities in the Waigatz Straits, on the Noursak Peninsula and Disco Island, where alone in all Greenland Miocene strata have been found. Extending over a very limited district, these strata are composed of a great variety of beds of sandstone, alternating with lignitic coal, and topped by shales of various descriptions. In all the sandstones and shales (with the exception of the coarse grits) I found more or less of vegetable impressions, but it was only in the thin layers of a hard clay slate impregnated with iron that they retained their impressions very distinctly. All these strata were cut across by trap-dykes, in some places standing out bare and wall-like from the denuded softer strata through which they had protruded. In other places the trap was interstratified with the sedimentary rocks, and in others again it stood out in bold basaltic (amorphous) headlands or skerries in the sea, from which circumstance, indeed, the principal fossil locality, At-ān-ak-ērd-lŭk (‘the rocks in the sea’), gets its name. ‶The stems I found at Kudlesaet, in lat. (by my observations, August 26, 1867) 70° 05′ 35″ N., wholly imbedded in coal in a horizontal position. The beds

On the Metamorphic and Metalliferous Rocks of Eastern Nova Scotia

I n those parts of Nova Scotia lying eastward of the Shubenacadie River, and northward of Mines Basin and Channel, about half of the surface is occupied by carboniferous beds, whose arrangement has been noticed in various papers communicated to this Society. The remainder, with the exception of a few small patches of new red sandstone and unaltered Silurian strata, consists of metamorphic rocks, for the most part older than the carboniferous system. These metamorphic rocks may, by evidence derived from mineral characters, geographical distribution, and associated fossiliferous beds, be divided into two great groups, which, so far as I am aware, have not hitherto been accurately distinguished by writers on the geology of Nova Scotia. In the present paper I propose to notice the composition, arrangement, and distinctive characters of these groups; and to describe, somewhat in detail, the metalliferous veins which have been discovered in one of them. I. One of these metamorphic groups is, in the part of the province now under consideration, limited to the Atlantic coast and its vicinity. The prevailing stratified rocks in this group are, compact and flaggy grey quartzite (often weathering white), mica slate, and clay slate; the latter usually of dark colours, and occasionally passing into flinty slate and quartzite. These rocks usually occur in beds of great thickness. The hypogene rocks associated with them are white and flesh-coloured granite, which has penetrated the metamorphic rocks in large irregular bands and masses. The white granite, which is the most

On the probable Age and Origin of a Bed of Plumbago and Anthracite occurring in mica-schist near Worcester, Massachussetts

A bed of plumbago and impure anthracite described by Professor Hitchcock in his “Geology of Massachussetts” is found interstratified with mica-schist near Worcester, forty-five miles due west of Boston. It is about two feet in thickness, and has been made use of both as fuel and in the manufacture of lead-pencils. It is much mixed up with the associated rock, has the touch and somewhat of the lustre of plumbago, and gives a streak on paper. It is occasionally iridescent like coal, contains pyrites, which is also found in the associated clay slate and garnetiferous mica-schist, both of which are impregnated with carbonaceous matter. This- plumbaginous rock presents numerous polished surfaces or slickensides, on some of which are delicate parallel striæ, which reminded me so strongly of the finely striated leaves common in coal, that I had first supposed them to be of the same nature; and was thus induced to search very diligently, but in vain, for vegetable impressions.

XXX. On bitumen in stones

In a Paper which I had the honour of presenting to the Royal Society on the 9th of May, 1822, I stated my intention of proceeding with an inquiry into the existence of bitumen in certain stones, not generally supposed to contain such a substance. The result of the investigation, I now beg leave to submit. In the Paper referred to, I described the manner in which the pulverised stone was distilled, in order to obtain the volatile ingredients. I had at that time detected a bitu­minous substance in two varieties of Pitch-stone, the Newry, and the Meissen. I have since subjected to the same process the following minerals, viz., 1. Arran Pitch-stone; 2. Pearl-stone, from Tokay, in Hungary; 3. Pumice, from Iceland; 4. Amygdaloid, from Disco Island; 5. Basaltic, or Secondary Green-stone, from Newry; 6. Transition Green-stone, from Carlingford Mountain in the County of Louth; 7. Bole, from Disco Island; 8. Basalt, from the Giants' Causeway; 9. Basalt, from Disco Island; 10. Transition, by some con­sidered Primitive Green-stone, from Clack Hill, near Castle Wellan, in the County of Down, Ireland; 11. Wacke, from Disco Island; 12. Iron Clay, from Disco Island; 13. Iron Clay,from Howth; 14. Hornblende, from Schneeburg, Upper Saxony; 15. Tourmaline, from Karorulik, in Greenland; 16. Augite, from Arendal, Norway; 17. Serpentine, from Zöplitz, Upper Saxony; 18. Clay Slate, from Bangor, North Wales; 19. White Felspar, from Killiney, near Dublin; 20. Flesh-red Felspar, from Aberdeen, Scotland; 21. Menilite, from Menil Montant, near Paris; 22. Adhesive Slate, from Menil Montant; 23. Mica Slate, from Freyburg, Saxony; 24. Mica, from the Ural Mountains, Siberia; 25. Obsidian, from the Lipari Islands; 26. Fetid Quartz, from Nantes in France; 27. Common Quartz; 28. Rock Crystal, from the Cape of Good Hope.

XIII.—Notices and Extracts from the Minute-Book of the Geological Society.

1. A Notice on Fossil Plants found at the Col de Balme, near Chamouny in Savoy .— By H. T. De la Beche, Esq. F.R.S. &c. [Read Nov. 3, 1820.] The Col de Balme, which closes the valley of Chamouny to the northeast, and separates Savoy from Switzerland, has long been known for the superb view which it commands of the valley of Chamouny, with the Mont Blanc range in one direction, and the mountains of the Valais in the other. The iron cross on the highest part of the Col, or passage, is, according to M. De Saussure, 7086 French feet (7558 6/15 English feet) above the level of the sea. The Col is composed of beds of clay slate, of limestone, and of a few thin beds of sandstone. The rocks of the Col de Balme have been called primitive by M. Ebel, in his Bau der Erde in dem Alpen-Gebirge; but were with more justice named secondary by M. De Saussure*. The beds which compose them seem to be a continuation of the limestones which are remarked in patches in the valley of Chamouny; and which probably once occupied the whole length of the valley. While crossing the Col de Balme, in the autumn of 1819, I picked up two portions of the thin beds of sandstone above mentioned, which I found to contain vegetable impressions, precisely similar to what have been termed coal-plants, because they are usually found in coal formations. But I tried in vain to

XII. Memoir on the Geological Relations of the East of Ireland.

Contents. INTRODUCTION, § 1 to § 4. FORM OF SURFACE. General view of the Limestone Plain; Mountain Groups; Eastern, Southern, Western, Central, and Northern Mountains and Hilly Tracts; Elevation of these respectively, § 5 to § 10. GEOLOGICAL RELATION. General distribution of the subject, § 11. I. Primary Tracts. Eastern mountain chain; general structure, § 12 to § 14. 1. GRANITE. Bounded by other rocks; its extent; structure; minerals found in it; contemporaneous veins; stratified, § 15 to § 20. 2. MICA SLATE. Eastern Division. —Its extent, structure, position; contact with other rocks; interstratified with granite, quartz, talc slate, and trap rocks; traversed by contemporaneous veins; minerals contained in it, § 21 to § 38. Western Division. —Extent; interrupted; bounded by other rocks; in caps; interstratified with granite, quartz, trap, and porphyry; contains discontinuous beds and veins of granite and quartz; minerals imbedded in it, § 39 to § 50. 3. CLAY SLATE. Western Division. —Extent; position; interstratified with trap and porphyry; with clay slate conglomerate, greywacke, and greywacke slate, and with granite, § 51 to 55. Eastern Division. —Extent; position; surrounds isolated portions of the fundamental granite; interstratified with granite, with quartz rock, greywacke, greywacke slate, trap, and porphyry; note on basalt; mutual relations of clay slate and quartz rock with hornstone and flinty slate, and with greywacke and greywacke slate; inflections of strata; general view of the stratified structure; distribution of metals through rocks; application of the term transition, § 56 to § 88. METTALLIFEROUS RELATIONS OF THE