Regional gravity and aeromagnetic data of Wales have been processed using a variety of techniques. Image processing has greatly assisted qualitative interpretation, whilst automated procedures have provided additional quantitative information. The shaded relief images emphasize gradients in the potential fields, and are useful for displaying strong linear features. The Euler deconvolution method produces plotted solution maps, which define the position of the source of the gravity and magnetic anomalies. Euler solution maps of Wales and the adjacent continental shelf are presented for the first time. These maps are interpreted in relation to the known geology, with special emphasis on the Lower Palaeozoic Welsh Basin. It is proposed that the Euler solutions define a network of fault-bounded blocks within the Precambrian basement.

Sir Andrew Ramsay has described the Coal-fields of the Forest of Dean, Somersetshire, and Bristol as outliers of the great Coal-fields of South Wales; there is, however, a marked thinning out in the thickness of the Carboniferous rock in the Forest of Dean as compared with the development of those rocks in South Wales and Bristol. At Clifton, near Bristol, the total thickness of the Carboniferous Limestone is about 2900 feet, at the northern end of the Forest of Dean Coal-field it is about 600 feet.

Based on the distribution of several stratigraphically important species three distinct larger foraminiferal zones are recognized in the Middle-Upper Eocene succession of Garo Hills, Assam, India. A comparison of these zones with larger foraminiferal assemblages from other Middle-Upper Eocene successions in the Indian region is attempted and observations are made on the demarcation of the Middle and Upper Eocene boundary and the classification of the Upper Eocene succession in this region.

The Paleocene locality of Menat (Puy-de-Dôme, France) has yielded several avian fossils, which remained poorly studied, even though some were found almost a century ago. Here, we review some of the material in public collections and show that those birds from Menat, which are at least tentatively identifiable, resemble taxa from early Eocene fossil localities. A largely complete skeleton of a medium-sized bird with strong feet shows affinities to the early Eocene Halcyornithidae and Messelasturidae, which are considered to be representatives of the clade including Psittaciformes and Passeriformes. Another skeleton of a small species resembles the Songziidae from the lower Eocene of China, which are representatives of Ralloidea, the clade including Rallidae and Heliornithidae. A new and previously unreported specimen exhibits exceptional soft tissue preservation, in that the bones appear to be largely dissolved but the podotheca of the feet and even the soft parts around the shank are visible; the plumage remains of this specimen furthermore show an unusual bluish hue.

The North Pacific Ocean (NPO) has received abundant aeolian dust transported by westerlies from the Asian inland. The aeolian components preserved in NPO sediments record information on palaeoclimatic and palaeoenvironmental changes in Asian source areas at different timescales. Previous studies have systematically investigated the source–sink effect of aeolian dust using the sedimentology, geochemistry, isotope and magnetic methods. In this study, we focus more on recent developments of aeolian signals in NPO sediments obtained by magnetic approaches. Generally, aeolian components contain a mixture of magnetite, maghemite, hematite and goethite of different origins. Magnetic properties (mineral category, concentration and particle size) of these minerals are modulated primarily by climatic/environmental conditions in source areas and sorting effects during the transportation process. Compared with the other methods, magnetic measurements have the advantages of non-sample destruction, high sensitivity and high efficiency. Finally, future studies are also discussed to address the importance of magnetism for tracing the dynamic transportation processes of the aeolian dust.

A detailed gravity survey, carried out to determine the thickness of the Bovey Tracey beds, is described. After removal of the regional gradient a residual gravity anomaly of – 15 mgal can be attributed to the Bovey beds. This has been interpreted assuming that the clay density increases with depth and a maximum Bovey bed thickness of 1245 m is predicted. The western contact of the basin is shown to be faulted with dips of up to 63° and is possibly an extension of the Lustleigh–Sticklepath fault system.

Detailed mapping of the Precambrian rocks of the Llangynog Inlier, made possible by a series of new exposures, has allowed the establishment for the first time of the 1100 m thick succession within the Precambrian rocks of the area. All boundaries of the Precambrian rocks with younger strata in the area are either faults or unconformities. Some 350–400 m of rhyolitic lavas form the oldest rocks seen in the area; they are extensively silicified and devitrified and show little of their original texture, although flow-banding is visible in some outcrops and the presence of perlitic and snowflake textures imply that originally they were glassy in part. These lavas are succeeded by a varied succession dominated by volcaniclastic siltstones showing evidence of shallow water deposition and containing medusoids and trace fossils of Ediacaran age. Interbedded in the sediments are basaltic lavas, autobreccias and rare hyaloclastites displaying textural features characteristic of submarine eruption, and rhyolitic pumiceous and shardic ash-flow tuffs. The name Coomb Volcanic Formation is proposed for this succession, within which are recognized two members, a lower Castell Cogan Rhyolite Member succeeded by the Coed Cochion Volcaniclastic Member. In association are varied intrusions, comprising both dolerites and dacites. A palaeoenvironmental model, built on evidence of petrography, palaeontology and sedimentology is that of shallow water to emergent volcanic islands.

A significant 5- to 30-metre-thick interval of siliciclastic turbidites forming the First Flysch is present in the deep-water succession of the Pindos Zone. Nannofossil investigations in the central parts of the Pindos Mountains of mainland Greece indicate an assemblage of the Marthasterites furcatus zone (CC13). The presence of M. furcatus, together with common Quadrum gartneri suggests that the turbidites were deposited mainly during the middle to upper part of the late Turonian. The siliciclastic turbidites are interpreted as deposits of a lowstand fan as a result of a pronounced short-time eustatic sea-level drop in the late Turonian.

The northernmost exposures of rocks formed during the Late Neoproterozoic Cadomian orogeny in the Channel Islands–northern France region occur on Alderney. The island mainly comprises foliated quartz diorite, once considered to be 2 Ga, pre-Cadomian basement, and an undeformed basic to intermediate plutonic complex. A precise age of 610±2 Ma, based on U–Pb analyses of single and small groups of zircons, for the foliated Fort Tourgis quartz diorite demonstrates that the oldest rocks were emplaced and deformed during a Cadomian magmatic event. The age is virtually identical to ages from similar, foliated syntectonic quartz diorite bodies on the islands of Guernsey and Sark and at La Hague (north Normandy), indicating that this magmatic and deformational event was regional in extent. Discordant zircon xenocrysts define an upper intercept age of c. 2 Ga indicating the presence of Palaeoproterozoic basement at depth. Single zircons from the undeformed Bibette Head granodiorite give a precise U–Pb age of 572±1 Ma. This age is closely similar to that for the emplacement of the Northern Igneous Complex of Guernsey. The emerging data indicate that Cadomian magmatism in the northern Channel Islands region was not a protracted continuum, but occurred during two distinct, short-lived events separated by c. 30–40 my.

Phacopid trilobites are relatively widespread in Devonian deposits of north Gondwana and some have been collected from several sections of the Saoura Valley in SW Algeria. New occurrences of phacopids assigned to Trimerocephalus, Dianops and Phacops sensu lato are described from this area and comparisons are made with closely allied species from Morocco and Europe. The trilobite assemblages of the ‘Argiles de Marhouma’ Formation are considered to be Frasnian–Famennian in age. These new occurrences have been integrated into an analysis of Upper Devonian phacopid biodiversity. Diversity fluctuations reflect environmental changes, bioevents and stratigraphic turnovers throughout the Upper Devonian. Peak diversity was attained after the post-Kellwasser event.

Jointing in some ‘ironstone’ intraclasts in a sandstone from the Sydney Basin, New South Wales shows that the joints were developed prior to contemporaneous erosion. A number of other features observed in the Sydney Basin sequence support this conclusion and suggest that an anisotropic horizontal stress field developed in the sediments very soon after their deposition.

Major stratigraphical inversions are recognized in two parts of the Sulitjelma area, on the border of Norway and Sweden. In the Otervatn area, inversion is directly demonstrated by way-up structures in pillow lavas of the Sulitjelma Amphibolite Group. The porphyritic amphibolites of the group belong to a penecontemporaneous sheeted intrusive complex which originally underlay the pillow lavas. The other inversion, S of Sorjusjaure, is proposed in order to simplify the stratigraphical succession of the area. The inversions are both thought to belong to the inverted limb of the Gasak Nappe, which is the upper tectonic unit at Sulitjelma. Folding associated with the inversion could cause tectonic repetition of the strata-bound Sulitjelma ore horizon.

Significant quantities of clinoptilolite-heulandite, lesser amounts of low tridymite-cristobalite, sparse euhedral biotite, apatite and fresh plagioclase accompany the abundant smectite in the mudrocks from the Corallian sequence in the Baulking and Uffington boreholes. The association is thought to be genetically related, of volcanic origin and formed from the in situ decomposition of volcanic ash. Smectite concentrations fluctuate, showing five maxima, but are unrelated to lithology and hence to environment. This suggests repeated ash-falls during the Corallian sedimentation in the Berkshire area. The initial volcanic episode appears to have been contemporaneous with the shoaling which initiated Corallian sedimentation in southern England, suggesting a common tectonic control.

During the last few years a considerable number of Crocodilian remains have been collected from the Middle and Upper Eocene beds of the Fayûm, most of these specimens having been obtained by Mr. H. J. L. Beadnell in the course of his excavations in that locality. This material has recently been examined and determined, and it is found that several new species belonging to the genera Crocodilus and Tomistoma are represented by more or less complete remains. In the present note it is proposed to give a preliminary account of these new forms, which will be fully described and figured in the Catalogue of the Tertiary Vertebrata of the Fayûm now in course of preparation.

The line of demarcation between the Pliocene and the Pleistocene systems is of more importance than would at first sight appear, if for no other reason than because when stratigraphers and palaeontologists are forced by one consideration or another to use the system in preference to the stage names it is often impossible to gather the actual age which they attribute to the deposit or fauna which they are describing. This paper aims at explaining my own point of view, by which I hope to incline adverse scientific opinion towards a definite predilection for the division which I myself favour. Perhaps this may eventually lead to a pronouncement on the question by an authoritative international committee.

Maps showing depth to the Moho, the 6 km/s and 7 km/s isovelocity surfaces and the thickness of the crust with a velocity greater than 7.0 km/s for the UK and surrounding continental crust have been generated from a compilation of wide-angle/refraction data. The data show that the crust beneath northwestern Scotland is thinner and of higher velocity than that beneath southern Britain. The lower crust beneath the East Irish Sea and parts of the southern North Sea is formed from thick layers of high velocity rock. The lateral extent of these layers cross-cuts the downward projection of major structures mapped at the surface. This suggests that the major structures do not bound regions of lower crust with contrasting properties at depth. Instead these structures may be overprinted by modification of the lower crust, for example, by magmatic underplating, which is not observed directly at the surface. Mapped variations in crustal thickness do not mirror the variations in surface topography, which appears to contradict the view that the crust is in Airy isostatic equilibrium.

In the paper on Coniferous Fruits I described in detail the structure of three cones which had originally been described as, and all. along believed to be, Cycadean. These cones were Zamiostrobus macrocephalus, Endl.; Z. ovatus, Göpp; and Z. Sussexiensis, Göpp. In making, in June last, a careful comparison between the version of M. Brongniart's important essay, “Exposition Chronologique des Périodes de Végétation et des Flores diverses qui se sont succédé a la surface de la Terre,” published in the Dict. univ. d’Hist. Nat. 1849, and the version in the Ann. des Sc. Nat., Ser. III., Vol. xi., p. 285, bearing the same date, but which evidently, from the occasional emendations, had had a careful and later revision by its learned author than the copy with which I had heretofore been working, I found that M. Brongniart had already referred two of the species to the genus Pinites. On a foot-note on pp. 317, 318 of the volume quoted he gives the following reason for this change: “Un échantillon de ce fruit (Zamiostrobus macrocephalus) qui vientde m’être communiqué par M. Wetherell, établit d’une m.anière bien positive que ce n’est pas un fruit de Zamia, mais un cône de Pinus ayant tous les caractères de ce genre, relativement à la forme et à la direction des écailes, et à la position des graines géminés a leur base. Quant au Z. Sussexiensis, son analogie avec le précédent me paraît évidente.” To M. Brongniart then belongs the credit of having first correctly determined the affinities of these two cones, and they must be quoted as Pinites macrocephalus, Brongn., and P. Sussexiensis, Brongn.

The good exposures of virtually undeformed Callovian and Oxfordian strata along the Djeffara escarpment of southern Tunisia and northwestern Libya have allowed analysis of regional depositional history during this time.

A number of lithostratigraphic problems are considered. In Tunisia, the Foum Tatahouine Formation is subdivided into members and in Libya some of the stratigraphic issues are clarified. A correlation between the two sequences is proposed. The widely claimed aeolian origin for the Libyan Chameau Mort Sandstone is rejected.

The depositional patterns of the Callovian and Oxfordian strata are described in the context of Mid and Late Jurassic sedimentation in the eastern Ghadames basin of the African craton. After a regressive Bathonian sequence, transgressive conditions commenced in Early Callovian time. In a series of continental–marine cycles, this transgressive sequence culminated in widespread shallow, restricted-marine micritic deposition. A regression in Late Callovian time resulted in emergence marked by a thin but widespread calcrete horizon. In Mid? Oxfordian time a renewed transgression brought in open marine, high-energy, shallow-water carbonates. Later, regressive conditions returned, leading to increasing restriction, and latest Jurassic time saw the first signs of the fluvio-deltaic deposition that was to dominate the region in Early Cretaceous time.

The trilobite family Lichidae is represented in the Middle Ordovician of Virginia by silicified remains of species of Hemiarges and Amphilichas. One new subspecies, Hemiarges turneri Chatterton & Ludvigsen rasettii, is described. Development stages of both genera are illustrated. The bulla of H. turneri rasettii appears in the meraspis, whereas it is present in the protaspis of a Devonian species. The late metaprotaspis of Amphilichas has a small fixigenal spine, a feature shared with protaspides of the family Odontopleuridae.

Upon glancing at the map of Western Australia, the eye is at once attracted by a series of large lakes in the interior: which are further often emphasized by being coloured blue. The natural inference is, that they represent sheets of water, either fresh or salt.