Garnet-bearing xenoliths from Letseng-la-Terae display a range of textures from coarse to granuloblastic. Equilibration temperatures and pressures of primary phases are in the ranges 950-1400°C and 27-50 kb, respectively. Deformed lherzolites equilibrated throughout this temperature range but coarse xenoliths are restricted to low temperature equilibration.

All garnets display coronas developed during the reaction:

In some rocks, reaction has completely eliminated garnet.

In rocks where garnet is disrupted, the corona minerals are strung out in the fluidal texture indicating that reaction occurred before deformation. Rocks transitional to, and of granuloblastic texture, contain garnet and aluminous spinel; in addition ‘pools’ of minerals originating by dynamic separation of corona fragments are observed.

Chemical comparison between the corona minerals and minerals in a garnet-spinel rock and two spinel granuloblastites, suggests that these spinel-bearing rocks may be derived from normal garnet peridotite by a complex sequence of reaction, followed by deformation, annealing and chemical homogenisation. The conclusion that reaction and deformation took place at high levels in the upper mantle is contrary to some earlier hypotheses of shearing within the low velocity zone in response to continental plate movement, but is consistent with mantle diapir models.

Au retour de sa belle campagne de 1902 à 1904 dans l'Antarctique, M. le Dr. WILLIAM S. BRUCE m'a fait l'honneur de m'offrir l'étude des Spongiaires recueillis à bord de la Scotia. Voici de quoi se compose cette collection qui, à certains égards, offre un intérêt considérable.

The disintegration of solid bodies by means of active or feeble solvents, or by those invisible processes which go on during long periods of time, has, so far as I know, been studied neither by the chemist nor the natural philosopher. In 1837 I submitted to this Society a paper “On the Optical Figures produced by the Disintegrated Surfaces of Crystals,” containing experiments which I believe have not been repeated, and results which no person has attempted to explain. Since that paper was published, my attention was called to the structure and properties of decomposed glass, in consequence of having had occasion to study the action of its coloured films, in absorbing definite parts of the spectrum.

The origin of a suite of ultrabasic and basic rocks from the Letovice crystalline complex in the eastern part of the Bohemian massif, Czechoslovakia, is discussed on the basis of new geological and geochemical data. Strongly serpentinised spinel peridotites, plagioclase peridotites and pyroxenites, together with metagabbros, amphibolites and minor dykes of metadolerite, make up about 70% of the complex; metasediments, mainly mica schists, make up the remaining 30%. The ultramafic and mafic rocks constitute parts of a dismembered ophiolite considered to have been formed in the Cadomian episode. They show effects of polyphase deformation and were variously metamorphosed under conditions of greenschist to garnet amphibolite fades at 400–600°C and 2–5 kb. Geochemical features of the ultrabasic suite are similar to those of other ophiolite complexes, such as those of Bay of Islands, Oman, Papua, Pindos, Sarmiento and Troodos and are likely to be products of a marginal sea environment.

On the 3d November 1869, a huge Finner whale was stranded on the beach at Gosford Bay, Longniddry, Firth of Forth.

Most of the large Fin whales which have been examined by British and Continental anatomists have been found floating dead on the surface of the sea, and have then been towed ashore by their captors. But, from the account which was given in the Edinburgh daily newspapers, it would appear that, for some days previously, this animal had been recognised by the fishermen, swimming to and fro in the Firth. On the morning of the 3d it was seen from the shore, blowing with great violence from its nostrils, flapping its huge tail, and obviously struggling to disengage itself from the rocks and shoals, amidst which an unusually high tide had permitted it to wander. Shots were fired at it, and, from the wounds produced, blood poured forth which tinged the surrounding waves. As the tide receded, the animal was fairly stranded; and, after some vigorous but ineffectual attempts to disengage itself from its position, it slowly died. The animal lay some yards above low-water mark, so that for several hours each day it could be examined, and photographs taken from various points of view.

In an account of the Jurassic flora of Sutherland, published in 1911, it was stated that a few petrified specimens from Eathie Bay, Cromarty, and from Helmsdale on the coast of Sutherland, would be dealt with in a subsequent paper. One of the best preserved of them forms the subject of a recent communication to the Royal Society of London. The majority of the specimens described in the following pages are from the Hugh Miller collection in the Royal Scottish Museum, Edinburgh. We take this opportunity of expressing our thanks to the Director of the Museum for the loan of the fossils, and for permission to have sections prepared for microscopical examination. For the loan of the section reproduced in Plate II. fig. 19 we are indebted to the generosity of Dr Kidston.

The paraphyletic genus ‘Paleorhinus’ is understood currently as a cosmopolitan phytosaur taxon from the Late Triassic. There is no consensus regarding the number of species of ‘Paleorhinus,’ with multiple species and genera synonymised into a single genus or even a single species at various points in its published history. The taxonomy is confounded by historical descriptions without the benefit of comparisons to more recently collected specimens, emphasis on plesiomorphic cranial morphology as diagnostic features of the genus, and lack of cladistic analyses. When included in a recent explicitly cladistic phylogenetic analysis, the holotype of ‘Paleorhinus’ scurriensis (TTU P-00539) was found to be the earliest-branching phytosaur with respect to other North American specimens previously referred to ‘Paleorhinus,’ and is generically distinct from Paleorhinus. ‘Paleorhinus’ scurriensis differs from all known phytosaurs in five unambiguous characters: basitubera widely separated mediolaterally; ridge present on lateral surface of jugal; thickened shelf present along posteroventral edge of expanded pterygoid-quadrate wing; ‘septomaxillae’ separated and excluded from internarial septum; and nasal swelling present posterior to posterior borders of nares. This detailed morphological description of an early-branching phytosaur taxon is a first step towards resolving long-standing issues surrounding specific anatomical features and relationships among early members of the clade.

The Late Triassic reptile Leptopleuron lacertinum Owen, 1851 is described for the first time in full anatomical detail, based on newly produced silicone and plastic casts of the numerous specimens preserved as natural moulds. Previously, only the braincase has been described from these detailed casts. Leptopleuron is reconstructed as a 270-mm-long reptile with a long tail, although it is possible that even the largest known specimens were still sub-adults. Within Procolophonoidea, Leptopleuron is distinguished by the following non-braincase autapomorphies: two flattened, triangular spines of equal size on the quadratojugal; V-shaped groove on the jugal; the anterior tip of the jugal in contact with the posterolateral extension of the nasal; minimal contact between the jugal and the postorbital; frontals narrow anterior to the orbitotemporal openings; the vomerine dentition consisting of a tall and a short pair of fangs; broad medial ridge of pleurocentra of the dorsal vertebrae divided into three separate ridges by two deep grooves on each pleurocentrum; distinct three-fold depression pattern on the ventral side of ischium; and the first phalanx on the fifth pedal digit being long and slim. Leptopleuron shares some features with living sand lizards and might have lived a burrowing lifestyle. The dentition and body shape of Leptopleuron imply it ate a diet of fibrous plant material or hard-shelled invertebrates.

A section of the Vitabäck Clays at Eriksdal in southern Sweden was sampled for vertebrate fossils. Large bulk samples were collected from three horizons, including two coquina beds, VC3 and VC11, and a silty clay bed, VC7. Shark teeth are very common and constitute the main portion of the vertebrate material discussed herein. The selachian tooth faunas are almost exclusively represented by hybodonts, although a single tooth from a neoselachian shark, Squatinidae indet., was recorded from one horizon (VC3). Hybodont species identified from the Vitabäck Clay samples include Egertonodus basanus, Hybodus parvidens and Parvodus rugianus. Hybodont remains, other than teeth, include five morphotypes of placoid scales, incomplete cephalic spines and fragmentary fin spines.

Other fossil groups represented in the sieved residues from the bulk samples include bivalves, gastropods and bony fish. Together with the selachians, they indicate fluctuating palaeosalinities in the area. The lower coquina bed, VC3, includes taxa indicating mesohaline conditions while the composition of the fauna in the other coquina bed, VC11, suggests oligohaline settings. In bed VC7, the presence of amphibian remains and the rarity of selachian fossils indicate an even lower salinity. Palynomorphs from the basal part of the section, immediately below bed VC3, indicate an earliest Cretaceous (Berriasian) age.

Among the problems for the study of which the remarkably varied geology of the British Isles offers peculiar facilities, perhaps none ranks higher in importance or in general interest than the history of volcanic action. Placed on the oceanic border of an ancient continental area, the region of Britain has lain within the limits where hypogene activity is specially prone to manifest itself. From early geological times this activity has been displayed in various characteristic forms. Hence, within the geological records of Britain there has been preserved a more continuous and complete chronicle of volcanic phenomena than, so far as I am aware, has yet been discovered in any tract of similar size on the face of the globe. The rocks of the country have been investigated so long and so minutely that their general chronological succession has been accurately ascertained, and hence the precise horizon of each volcanic episode can be definitely fixed. The varying phases of eruptivity in different geological periods can be made out, and a large body of evidence can thus be amassed bearing on the general question of the past history of volcanism.

A summary of previous gravity and magnetic field interpretations is presented along with a review of the LOWNET and LISPB models. Recently acquired seismological data are compared with the LISPB upper crustal model. The LISPB Layer 1 is found to represent an average of lower velocity (VP = 3·0–3·7 km s−1) Carboniferous and Upper Old Red Sandstone sediments, and higher velocity (VP = 4·0–5·5 km s−1) Lower Old Red Sandstone and Lower Palaeozoic sediments.

On the basis of high P-wave velocities along strike (VP = 60·6–1 km s−1), the LISPB Layer 2 S of Glasgow and Edinburgh is re-interpreted as a quartzofeldspathic crystalline layer of igneous or metamorphic origin, which is also seen to cross the surface of the Southern Uplands fault at around 2·5 km depth.

This interpretation implies that within the southern part of the Midland Valley, the Lower Palaeozoic sediments are nowhere thicker than about 3 km, as postulated under the Silurian inliers, and generally much less.

Most zoned plutons described in the geological literature have mafic rims and felsic cores and are referred to as “normally zoned”, whereas relatively few “reversely zoned” intrusions (felsic rims and mafic cores) have been described. That unusual zonation pattern has been variously attributed to in situ processes or to the reordering of an underlying, vertically stratified, magma chamber either by intrusion through an orifice or by emplacement of composite diapirs. The Turtle Pluton is an early Cretaceous, reversely zoned, intrusion that is divided into four facies: a Rim Sequence that is graditionally zoned from bt + ilm + muse monzogranite to hb + bt + mt + sph granodiorite; a Core Facies of more homogeneous hb + bt + mt + sph granodiorite to quartz monzodiorite; between these two facies, a structural discontinuity termed the Schlieren Zone; and an Eastern Facies of monzogranite to granodiorite. Field relationships, distribution of strain, and geochemical and isotopic studies (including a range of initial87Sr/86Sr from 0·7085–0·7065) suggest that the reverse zonation of the Turtle Pluton is the result of sequential emplacement of two diapirs each derived from the same underlying, vertically stratified, magma chamber, and that the Rim Sequence zonation is chiefly the result of mixing of intermediate and felsic magmas from distinct sources accompanied by minor fractional crystallisation.

Since the publication of my “Report” in December 1899, Mr Tait, fossil collector to the Geological Survey of Scotland, has been successful in adding a number of specimens of great interest to the valuable series of Scottish Silurian Fishes which supplied the material for that memoir, and with the permission of the Director of the Survey, to whom my best thanks are due, I propose to give descriptions of them in the following Supplement. The search for these remarkable fishes has likewise been taken up by private collectors, and I have therefore pleasure in acknowledging my indebtedness to Messrs J. Young, of Lesmahagow, P. Macnair, of Glasgow, A. Whyte and F. White, of Muirkirk, and D. Nimmo, of Hamilton, for kindly submitting to me the material resulting from their own work in this field.

Six new specimens of petrified cupules of Hydrasperma cf. tenuis from Oxroad Bay, East Lothian (Cementstone Group) have been examined. Sections of one show a close similarity in size and shape to compressed cupules of Sphenopteris bifida L. and H. from the Lewis Burn (Scremerston Coal Group or lower Viséan) of Northumberland. The conclusion reached is that cupules of Hydrasperma cf. tenuis Long are petrified equivalents of the compressed cupules of Sphenopteris bifida L. and H. The morphological significance of this identification is discussed.

Macrurous decapod crustaceans are generally uncommon and are often incompletely preserved. However, at certain horizons in the Speeton Clay (Ryazanian–Albian) and Atherfield Clay (Lower Aptian) of Yorkshire and the Isle of Wight respectively, macrurans form the dominant element of the fauna. Two species in particular, Meyeria ornata (Phillips) and Meyerella magna (M'Coy), are not only very common in these formations, but are also very well preserved. Recent collections have yielded a large number of specimens of both species. This material is examined with the aid of SEM techniques, gross morphology is discussed, and the details of the exoskeletons are compared. In the case of M. magna, examples are figured which show traces of a colour pattern and the effects of regeneration on the first pereiopods. A discussion is included of the possible function of the appendages in M. magna and M. ornata, and of their other, unique features. Finally, the mode of life of both species is inferred from a consideration of their morphology, and of the evidence from their preservation, distribution and relationships with associated faunas.

Graphite bodies of economic importance occur in the Eastern Ghats migmatite complex of Orissa, India, which consists of sillimanite-rich gneiss (khondalite), calc-silicate granulite, basic (pyroxene) granulite and acidic gneiss palaeosomes and a variety of quartzofeldspathic neosomes and pegmatite veins. There is more graphite in migmatised khondalite and calc-silicate granulite than in their unmigmatised counterparts and it is common at pegmatite-country rock margins. Lodes of graphite are structurally controlled by fold hinge zones, necks of boudins and along the dominant foliation in rocks that show the effects of polyphase deformation. Faults, fractures and joints also act as structural controls. The richest lodes are located where there is the coincidence of several lithological and structural features.

The graphite occurs in graphite-rich schists and gneisses, as veins and as disseminated flakes along grain boundaries and in microfractures and cleavages. It is present in all rock types except pegmatites emplaced after the D4 deformational phase, and is localised in structures developed during the D1, D2, D3 and D4 phases. Most of the bodies of graphite are lenticular and show pinch and swell characters. Fourteen textural and microstructural habits have been recognised and are described with many of the features of fabric, such as intergrowths, inclusions and kinks being particularly well shown under reflected light.

Methanation of carbonate minerals is considered the most likely initial stage in the formation of the carbon with subsequent pyrolysis of the methane being the process of graphitisation. While the possibility of the carbon being either of sedimentary derivation orfrom igneous-derived CO2 cannot be ruled out, there is no convincing evidence for such sources. Remobilisation of graphite following its formation by pyrolysis of methane in structurally controlled low pressure zones is the dominant mechanism of concentration. Thefabric features point to the graphite having moved as a solid phase along open spaces inthe gangue minerals while still maintaining its crystallinity, and having been deformed in the process. The effects of remobilisation apparently have obliterated evidence relating to other methods of concentration.

1. Every purely periodical function is, as is well known, expressible by means of a series of constant coefficients multiplying sines and cosines of the independent variable with a constant factor and its multiples. This important truth was arrived at by an admirable piece of mathematical analysis, called for by Daniel Bernouilli, partially given by La Grange, and perfected by Fourier.

Studies of the chemistry of Lower Carboniferous igneous rocks in the Midland Valley of Scotland throw light on the nature and magmatic evolution of transitional basaltic suites. Major oxide and trace element chemistry of least altered lavas of the Campsie Fells reveals a lower group of basalts, basaltic hawaiites and hawaiites, and an upper, more variable group, ranging from basalt to trachyte. Chemical composition of associated vent intrusions confirms their association with the lower group of flows. The magmatically evolved condition of the erupted material indicates high-pressure fractionation of clinopyroxene at depth followed by fractional crystallisation of olivine, plagioclase and Ti-Fe ores at lower pressures. In the case of the upper lavas, further differentiation appears to have taken place in a shallow magma chamber under a central volcano.

The observed chemical variations in the Campsie Fells and other areas of Lower Carboniferousvolcanic activity can be attributed to a number of different factors during the evolution of the magmas. Detailed studies of the cumulative phases of the lavas may throw further light on the various stages involved.

The following observations were made during a prospecting expedition which left the Falkland Islands in the late spring of 1913 for the South Shetlands, the Palmer Archipelago, and Graham Land. The cost of the expedition was provided by Messrs Salvesen of Leith, the well-known shipping and whaling firm, who are lessees from the Colonial Office of the minerals in these remote areas. Arrangements were made to prospect as large an area as possible during the whaling season 1913–14. The steamer Hanka, a modern whaler, proved very suitable for prospecting work, owing to its light draught, small size, and fairly high speed. It could, however, owing to its small capacity, operate only within a limited radius of a supply base, and Messrs Salvesen's big whaling factory ships in King George Island; Leith Harbour, Belgica Strait, Graham Land; and Fournier Bay, Schollaert Channel, Anvers Island, formed effective bases of supply.

A stem-base of Oxroadia gracilis is described showing 12 distal rhizophores and 72 roots. The rhizophores branch in a manner interpreted as dichotomy in successive planes at right angles. Each has a siphonostele which may possess medullary tracheids. Root-traces are monarch and wedge-shaped in section and their departure leaves ramular gaps in the siphonostele. The largest root may have functioned as a tap-root formed earlier than the rhizophores and exogenous. Only two out of ten known rooting specimens show rhizophores.

An aerial stem with leaves shows secondary xylem up to the level of the probable second dichotomies.

Leaves have slightly decurrent clasping bases forming low cushions and are recurved. Ligules (when preserved) occur in deep cavities of leaf-bases. In the apical region young leaves are small, recurved, and grooved distally below, giving a pseudo-forked appearance in cross sections of the stem.

Only incomplete strobili are known.

Comparisons are made with ‘Lepidodendron’ saalfeldense Solms-Laubach, and Trabicaulis ftabellilignis Meyer-Berthaud; these are considered co-generic.

Oxroadia is recorded from the Oil-Shale Group (late Viséan or Asbian) near Kinghorn, Fife, Scotland; and from the Cementstone Group (late Tournaisian or Courceyan) East Lothian, Scotland; Berwickshire, Scotland; and Northumberland, northern England.