ALBERT

Beschreibung: At the Bournemouth meeting of the British Association in 1919, Dr. J. W. Evans, in his characteristically stimulating address to Section C, pleaded for the closer examination of sediments by geologists in the field. He instanced especially the presence of rhythmic banding on a small scale in sediments of widely varying ages as a phenomenon badly in need of further study. Engaged in field work on the oil-bearing Tertiary rocks of Burma, the writer has been struck by the repeated occurrence of rhythmic banding in those beds. The present note embodies the firstfruits of the detailed examination of the banding.

Beschreibung: In the course of detailed mapping over this area, with a view to throwing some light on the complicated geological structure of the district, the discovery of various graptolites, largely from new localities, both confirms and extends the previous records of Dr. C. A. Matley and Mr. W. Keeping.

Beschreibung: In a former paper, a short sketch of the geographical and geological features of Western Togoland was given. The main geological divisions, excluding recent deposits, may be tabulated thus:-

Beschreibung: The limestone hills of the Kinta Valley, standing up with white cliff faces from an almost level plain, form a prominent and picturesque feature of this prolific tinfield, and attract attention and present a varying scene as viewed from different points in the valley of the Kinta River. Their mode of origin has been the subject of marked divergence of opinion amongst geologists acquainted with them, as has also their age in relation to the series of metamorphic sediments found in the same valley.

Beschreibung: In his paper on “The Yellow Limestone of Jamaica and its Mollusca” (Geological Magazine, Vol. LX, 1923, p. 345) Dr. C. T. Trechmann referred to an Upper Senonian fauna from shales at Providence, near Port Antonio, underlying a limestone with Rudistae. He recorded Baculites from the upper portion of these shales, and “rather low in the sequence” he collected some ammonites, one of which had been identified by the writer as belonging to the genus Parapachydiscus. The Shales at Providence had already been mentioned by the late Mr. Lucas Barrett1 as containing Baculites and Hamites, and in his collection, now in the British Museum (Natural History), there are preserved a number of fossils including the Pholadomya and Trigonia he recorded and two fragments of Hamites. The matrix of these is the same as that of Dr. Trechmann's examples, namely a brown calcareous sandstone, and the ‘Hamites’ in both collections belong to the same species, but Mr. Lucas Barrett's Baculites I have not been able to trace.

Beschreibung: SummaryFrom the foregoing notes it is evident that there exists in this part of the Kukuruku District an igneous series showing the familiar veining, banding, and mingling of rocks of increasingly acid composition, and also a group of completely altered sediments.

Beschreibung: In the erection of a new home of rest—St. Monica's, in the grounds of what was formerly Cote House, near the top of Westbury Hill, an interesting section1 of the upper part of the Old Red Sandstone and of the lower Avonian rocks up to the top of Zx was exposed in digging the foundations. Although the section lies only a little over a mile north-east of the Avon section and the general succession of the two is very similar, the Westbury section is of considerable interest, particularly as certain levels were well seen which are not exposed in the Avon section. In all the following tables the strata are described from below upwards.

Beschreibung: The question of the zinc content of the Ballachulish granodiorite (Geol. Mag., Dec, 1924, p. 554) has now been thoroughly investigated, Dr. E. G. Zies, of this laboratory, having very kindly interested himself in the matter.

Beschreibung: The following paper deals with the results obtained from investigations made during recent years in North Derbyshire with a view towards elucidating the relation of the so-called “Yoredale“ or “Pendleside ” Series to the Carboniferous Limestone.

Beschreibung: Summary(1) 510 plants are recorded from various localities in the coalfield, fossils having been collected from several new localities.(2) Fossil-plants are noted for the first time from the upper beds of the “Millstone Grit” of this district.(3) Two new species of Sigillaria are described and figured.(4) The known flora of the coalfield has been increased. Of the plants recorded—6 species have not been recorded previously from Britain.62 species have not been recorded previously from the coalfield, and290 species have not been recorded previously from various localities in the coalfield.Many of the species which have been previously recorded are here referred for the first time to definite horizons.(5) The known vertical distribution of 38 species is extended to the Staffordian Series.

Beschreibung: The genus Cyclus contains a number of small Arthropoda which are found in the Carboniferous rocks of Europe and the United States. As a rule the fossils are small, less than an inch in diameter, and very often they are enclosed in ironstone nodules. Consequently they are generally overlooked and are rarely found in collections.

Beschreibung: Small species of Chonetes are frequently found crowding the limestones in the lower part of the Avonian Succession round Bristol and in the Mendips. Of these Ch. cf. hardrensis (Phill.) is the most persistently abundant throughout its range Km-Zl, but the two other species, Ch.failmulensis sp. nov. and Ch. stoddarti, Vaughan, here mentioned, occur in equally large numbers at particular levels within that horizon. The following notes are the outcome of the study of the material recently collected by Professor S. H. Reynolds, and myself, at St. Monica's Home of Rest, Westbury-on-Trym, but this has been considerably supplemented by specimens obtained from other localities in the district.

Beschreibung: The following notice of some fossils recently collected in the northern Malayan Province of Kedah, has been prepared at the instance of Mr. J. B. Scrivenor, M.A., F.G.S., Government Geologist of the Federated Malay States. A study of this new material has rendered necessary the revision of a published paper by the late Professor T. Rupert Jones, F.R.S., dealing with some supposed Phyllopod valves from the same country which were obtained from similarly constituted rocks as those at Kedah, although occurring at a more southern locality in the adjacent province of Perak.

Beschreibung: SummaryThe more important points in connexion with the structure of D. flabelliforme are:—1. The absence of any real approach to the spiral arrangement of the thecae along the stipes.12. The absence of a common canal; and the consequent budding of each hydrotheca direct from the preceding one.13. The initial constriction of each hydrotheca cavity.4. The budding of the bithecae from the sides of the hydrothecae along which they lie.5. The early stage at which the presence of the bithecae is observed.6. The derivation, indifferently “right-handed” or “left-handed” of the crossing canal.7. The nature of the dissepiments—hollow bars derived principally as outgrowths of the bithecae.

Beschreibung: Pygidium elongated, sublanceolate, bluntly pointed posteriorly. Lateral lobes flattened, horizontal, composed of three pairs of pleurae and a median postaxial piece. Axis short, conical, convex, tapering rather rapidly to blunt tip, less than one-third the length of the pygidium and about one-third its width, subcarinate posteriorly, faintly marked off from postaxial piece by weak circumscribing furrow; furnished at anterior end with one strong narrow complete ring, marked off by strong furrow, followed by weaker second ring defined by faint complete furrow, and with traces of a third incomplete ring; posterior two-thirds of axis devoid of annulations. Postaxial piece long, narrow, widening somewhat posteriorly, descending gradually to level of lateral lobes from tip of axis and becoming flattened but distinctly carinated for its whole length. First lateral pleura strongly falcate, bending back suddenly at fulcrum where it is widest and thence narrowing rather slowly to acutely pointed free tip projecting backwards beyond margin; pleural furrow submedian, diagonal, parallel to posterior edge of pleura, running nearly to tip. Second lateral pleura elongate, sublanceolate with tip bent back slightly and projecting freely beyond margin as short recurved point; pleural furrow median, slightly diagonal, not reaching tip. Third lateral pleura sublanceolate, broader than second pleura, incompletely marked off from postaxial piece posteriorly, the bounding furrow not quite reaching the margin but curving gently outwards at its end; tip of pleura undefined and not projecting beyond margin; pleural furrow median, slightly wavy, running nearly straight back parallel to its fellow, curving inwards a little at its end but not clearly connected with bounding furrow. All pleural and interpleural furrows of equal strength. Posterior lateral margins of pygidium behind tips of second pleurae forming nearly half its length and describing a long simple slight curve on each side, uniting behind in a blunt point at about 60°, the median carina of the postaxial piece extending to its tip.

Beschreibung: For some years Dr. W. F. Hume had desired to obtain additional analyses of Egyptian igneous and metamorphic rocks for the purpose of a detailed investigation he proposed to make of their nature and distribution. The Chemical Department of the Egyptian Government was, however, too fully occupied on current work for Government contracts, and could not undertake the specialized analytical work necessary.

Beschreibung: The Lower Greensand forms a well-wooded range of hills in Kent and Surrey which is known in Kent as the Ragstone Range. Between Ashford and Leith Hill this range is broken by the consequent streams of the Stour, Medway, and Mole, and by the obsequent streams of the Shode, Oxted Brook, and that part of the Eden known as Gibb's Brook.

Beschreibung: Barbados, occupying as it does the position of the most easterly isolated and the furthest out in the Atlantic Ocean of all the West Indian Islands, deserves special attention from geologists. Its rocks consist essentially of three units each separated from the other by an important unconformity, namely in descending order the Coral Rock, the Oceanic Series, and the Scotland beds.

Beschreibung: In the Geological Magazine for May appeared an article by Dr. R. H. Rastall entitled “On the Tectonics of the Southern Midlands”, which I feel it absolutely necessary to criticize and correct in so far as it deals with evidence derived from Northamptonshire and quotations from my own papers, the latter in parts verbally accurate and yet altogether misleading as used; and I trust Dr. Rastall will accept the following corrections and additions rather as a contribution than an adverse criticism merely to his theory of “the recurrence of activity along old-established fold-lines of an early date–5, and will be separately referred to.

Beschreibung: It has become increasingly evident during the past few years that there are many geologists working on the older Palaeozoic rocks in various parts of the British Isles, to whom a knowledge of the common assemblages of graptolites characteristic of our different British graptolite zones might be useful. In the following lists, therefore, an attempt has been made to put together the facts gleaned from the study of the Graptolite Shales of the British Isles in many widely separated localities. The lists do not claim to be in any way a complete representation of the entire fauna of any zone, but merely an enumeration of those graptolites which in the author's experience are most universally and abundantly represented, so that they are likely to be the forms met with most characteristically in an exposure of any particular horizon. Some co-mingling at the boundaries of the zones must naturally be expected, especially when dealing with a succession of purely shaly deposits, but as a rule even then the coming in of new forms in abundance should be taken as an index of the passage to a higher horizon. This fact is one upon which great emphasis should be laid, it is upon this coming in of new forms, usually indicative of a more advanced stage in evolution, that the basis of modern zonal stratigraphy is laid; the persistence of old forms tends to vary greatly in different localities with the richness of the previous fauna; when the fauna of the earlier zones was both rich and varied, there are naturally more survivors into the succeeding zones than when the fauna was a poor one.

Beschreibung: Along certain of the coast sections in the province of Manabi, Ecuador, a series of large igneous boulders (of a coarse granitic type) occurs in situ among normal Tertiary sandstones. Tertiary sediments form the greater part of the “littoral” or coast belt of this country. One of the masses of rock referred to above had a weight, at least, of twenty tons—an exceptional size for an undoubted constituent member of a sandstone or a conglomerate.

Beschreibung: Although the full account of the Geological work carried out by the St. George Expedition to the Pacific must await the working out of the specimens collected, the following brief preliminary notes may be of interest.

Beschreibung: Chloritoid-Bearing schists have so far not been recorded from the State of South Australia, though such are known from the Pre-Cambrian rocks of the Broken Hill area. The chloritoid rocks now to be shortly described occur interbedded with quartzites, forming the meridional ridge of the “Frenchman”, on the western coast of southern Eyre Peninsula. In a previous paper (l)1 the rocks of this area have been referred to, as comprised within two groups, a sedimentary series—the Warrow series, and the Dutton series, a group of acid granites of gneissic habit with associated aplites and pegmatites, often rich in tourmaline and carrying garnet, and beryl. These rocks invade the sediments of the Warrow series.

Beschreibung: The fossil which forms the subject of this note was thought, when first found by me, to be a new genus of Tabulate corals. Since it may puzzle, and indeed has puzzled, others in a similar manner, it will perhaps prove useful to describe it.

Beschreibung: The composition of chalk has been shown to consist dominantly of three types of material, in the order of their importance, (1) amorphous, or extremely fine-grained material, (2) spheres, and (3) organic remains.The first, the writer believes, represents chemically precipitated calcite and aragonite, the second a chemically formed oolite, and the last the normal organic constituents.Recent studies have shown that the surface waters of the ocean in favourable localities are saturated with CaCO3 and that variations in amount of CO2 mean either solution or precipitation. It is believed that the physical conditions of the Cretaceous sea favoured precipitation. Bacteria may have been a contributing factor.It is hoped that the above suggestion of the possible chemical origin of a part of the chalk (the larger part) will cause those who have the opportunity of study to apply it further, for until the great amount of extremely fine material is accounted for the origin of chalk is not settled. The writer regards the chemical origin with favour because it seeks to explain the origin of chalk in the light of present knowledge of the precipitation of calcium carbonate from sea water.