The Upper Cretaceous (Turonian) Bissekty Formation of Uzbekistan has yielded many isolated bones and teeth representing a variety of non-avian theropod dinosaurs. A pedal phalanx II-2 indicates the presence of a dromaeosaurid theropod that attained a larger body size than any previously known member of that clade. The same formation also yielded a large maxillary fragment that has recently been described as a neovenatorid carcharodontosaurian (Ulughbegsaurus uzbekistanensis). However, this specimen lacks unambiguously diagnostic features of that clade, and its purported carcharodontosaurian characters are either taphonomic artefacts or also shared by dromaeosaurids. Thus, the phylogenetic relationships of Uleghbegsaurus uzbekistanensis remain uncertain. A giant dromaeosaurid occurred together with the medium-sized tyrannosauroid Timurlengia euotica in the Bissekty assemblage.

Turbidity currents commonly bypass sediment in submarine channels on the continental slope, and deposit sediment lobes farther down-dip on the flat and unconfined abyssal plain. Seafloor and outcrop data have shown that the transition from bypass to deposition usually occurs over complex zones referred to as channel–lobe transition zones (CLTZs). Recognition of these zones in cores and outcrop remains challenging due to a lack of characteristic sedimentary facies and structures. This paper focuses on Unit E of the Permian Fort Brown Formation in the Karoo Basin, South Africa, in the Slagtersfontein outcrop complex, which has previously been interpreted as a CLTZ. This study integrates thin-section micrographs, sedimentary facies, bed-set and stratigraphic architecture, and palaeoflow directions to achieve a multiscale analysis of CLTZ features. A novel process-based facies scheme is developed to evaluate deposits in terms of the depositional or erosional tendencies of the flows that formed them. This scheme allows bypass to be distinguished from depositional zones by the spatial distribution of certain sediment facies. Areas of net sediment bypass were predominantly marked by erosive sediment facies and a larger variability in palaeoflow direction while depositional areas showed a lower variability in palaeoflow directions. Metre-scale structures in the bypass-dominated area reveal seafloor erosion and scour formation. Field relations suggest the presence of a ∼500 m long mega-scour in the CLTZ. The characteristic structures documented here are applicable for identifying CLTZs in sparse datasets such as outcrops with limited palaeogeographical context and sediment cores obtained from subsurface systems.

Except in containing small nodules of phosphate of lime, the Chalk shows no structural change where it terminates in the Ely section, but passes down almost imperceptibly into a dark greenish layer, and rests on it at an angle of about 35°. This greenish band, scarcely a foot thick, is full of nodules of phosphate of lime, and consists largely of glauconite. It is the Upper Green-sand, with Ammonites auritus, Terebratula biplicata, Dentalium ellipticum, and the usual local features. Nowhere can the passage of one rock into another be more marked than that of the Upper Greensand of this district into the Chalk. Conditions have changed a little with physical geography, but nothing suggests any break in time. About Cambridge the section is exactly the same; the Chalk just above is often flaggy, contains a few green grains, a little phosphate of lime, and the commoner Greensand fossils mixed with those of the Chalk. Sometimes, however, there are some 10 or 12 feet of dark greyish-green marls above the Upper Greensand. They are separated by sharp lines of bedding from the Chalk, are very local, and perhaps only indicate a trifling denudation of the Gault.

It is fortunate that Captain Lelean not merely discovered these fossils at Garadimi in Sokoto, but that he had enough sense of their importance to spend some time and trouble in their collection, and that now he has generously presented them to the British Museum. The collection includes four echinoid tests, five natural casts of Mollusca, and a few rock-specimens containing Operculina and other Foraminifera. The Mollusca, so far as their state of preservation admits, have been determined by Mr. R. Bullen Newton as: 3 Lucina cf. gigantea Deshayes, 1 Voluta cf. cithara Lamarck, and 1 undetermined Gastropod. The Echinoidea were partly covered by an impure limestone closely adherent to the test. The portions not so covered were in many places considerably worn, and the calcite was split by cracks, probably due to alternations of temperature, and rendering it very difficult to follow the course of the sutures. The appearance of these and the other specimens shows clearly that they have been lying on the surface of the ground for some time, and, in fact, Captain Lelean informs me that they were not picked out of the solid rock, but from the talus at the foot of the cliff. The notable variations in the matrix of the different specimens are thus accounted for. None the less it will be seen in the sequel that all the specimens are consistent with the ascription of a Middle Eocene age to the mass of limestone from which they were derived. Of the four echinoids, two have been determined as belonging to the genus Plesiolampas and two to the genus Hemiaster.

It will be recalled that to the list of theories relating to the origin of flint Liesegang has added another, namely, that the flint is due to the rhythmic precipitation of a silica solution diffusing through the Chalk. Cole in an admirable essay has made this view accessible to English readers, and at the same time somewhat expanded the original suggestion. Yet little by way of evidence is offered beyond a certain plausibility in the idea, and its undoubted competence to explain better than any other hypothesis yet suggested the remarkably regular recurrence of flint lines. When reading over the chief Cretaceous literature with this problem in mind, there seemed to me to be a not inconsiderable body of fact lending support to this view. Accordingly the object of this paper is to examine existing data in the light of Liesegang's suggestion in order to see whether or not it may be regarded as a reasonable working hypothesis.

In a preliminary article (1) dealing with the British Quaternary strand-line oscillations it was shown that unexpected correlations had emerged as a result of the methods employed. Of the possible assumptions the only one to prove workable was that there had been, during Quaternary time, a temporary lowering of ocean level of 1,000 metres or more. The graphs left no reasonable doubt that if the ocean level had moved in the way assumed the Mindel-Kiss interval of Penck's Alpine sequence must be equated with the major glaciation of North-West Europe and the British Isles. In order to test this, the only assumption made, it was applied to the coral reef problem (2) and there it was successful in offering what should be an acceptable solution. It was surprising to find that Darwin had actually used an apparent rise of ocean level, of the same order of magnitude, to illustrate his own theory of subsiding islands. The success of the postulate when faced with the coral reef problem was held to have invested it with a high degree of probability. It was pointed out, however, that changes in ocean level of that magnitude could best be explained by the sinking of the ocean floor, and the North Pacific Ocean was indicated as the probable position. The cause of the changes of ocean level will now be investigated and then its consequences discussed in the light of ascertained facts.

IN the Geological Magazine for February, 1919, J. W. Jackson and W. E. Alkins described the occurrence of a quartzose conglomerate at Caldon Low, Staffordshire. In August one of us (F. B.) pointed out some previous references to this outcrop. The curious and ambiguous reply by Messrs. Jackson and Alkins

The theory of plate tectonics suggests that deformation occurs mainly along plate boundaries; however, compression can result in the formation of orogens and basins within intracontinental settings. During these two tectonic processes, the sedimentation and environmental changes occur in response to marginal and intracontinental deformation. Early Jurassic – Early Cretaceous deformation and basin formation along the Qinling orogenic belt and the northwestern Sichuan Basin in central–SW China are ideal for investigating a reactivated tectonic belt and basin formation. We studied the Lower Jurassic – Lower Cretaceous sedimentary sequences and structures along the northwestern margin of the Sichuan Basin, and obtained detrital zircon U–Pb ages for these rocks. The structures show that deformation migrated SE-wards and S-wards into the Sichuan Basin along the Longmen Shan, Micang Shan and Daba Shan tectonic belts during middle–late Mesozoic time. The Lower Jurassic oligomictic conglomerates have a smaller grain size and thicken towards the south, indicating protracted transport from a northern source. The conglomerates deposited near-source record post-orogenic south-vergent thrusting during the Late Triassic – Early Jurassic epochs. The Lower Cretaceous conglomerates and sandstones have multiple sources, which indicate that they were rapidly deposited near their source, synchronous with thrusting that occurred in response to coeval SE-wards and S-wards thrusting in the Longmen Shan and Daba Shan tectonic belts during the Late Jurassic – Early Cretaceous epochs. Detrital zircon grains from the Lower Jurassic – Lower Cretaceous sedimentary rocks yielded age peaks of 2600–2200, 1850–1600, 850–700, 540–400, 250–180 and 180–140 Ma. A comparison of these ages with those of surrounding exposed rocks indicates that the sediments in the northwestern Sichuan Basin were supplied from the Qinling orogenic belt, the northwestern Yangtze Block, the south margin of the North China Block and the Songpan–Garzê Terrane. The youngest peaks of detrital zircon U–Pb ages at 207 and 159 Ma constrain the two stages of intracontinental shortening and highlight the link between intracontinental deformation and sedimentation.

A Lower Cretaceous mixed carbonate-siliciclastic sequence is well exposed in the Zaraya Mountains in Guipuzcoa Province, northern Spain. The sequence begins with interfingering deltaic platform facies and marine patch-reef carbonates. This unit is dominated by mudstones and sandstone with minor interbeds of shallow-water carbonates (calcareous mudstones and sandstones and grainstone-packstones). A thick mixed carbonate-terrigenous unit overlies the siliciclastics and is composed principally of limestones and marls. Periodic influx of terrigenous sediments over a dominantly carbonate sea-floor gave rise to repeated cycles typical of a mixed shallow-water platform. Demise of the southerly derived deltaic input allowed the development of a mainly carbonate third unit. Large (several metres across) bioherms resulted from high in situ organic productivity (mechanical breakage of bioclasts, algal-induced precipitation, trapping and baffling of lime mudstone). The mounds grew making up a coral carbonate mound complex. This prograded to the south, towards a small backreef basin, and slightly retreated in its forereef margin. A period of tectonic instability is thought to have been responsible for the drowning of the shallow-water complex, which was unable to keep pace with relative sea-level rise.

The determination of the stability conditions of chlorite, especially the stability temperature between 500° and 700° C. by B. W. Nelson, D. M. Roy, R. Roy, and H. S. Yoder complements the conclusions arrived at from the microscopical study of the interstitial chlorite in the diabase-minverite series of south-west England. These disprove the assumption that the chlorite generally originates from metasomatic reaction or devitrification of a glassy residue. Considering the formation of chlorite at a late stage of solidification, an explanation of its genesis is attempted on that basis. Possible effects on the petrologic evolution are discussed.

The chlorite taking part in the filling of amygdales and pseudoamygdales has formed preferentially by replacement of carbonates. Variation in form, degree, and associated products is exemplified. The appearance of a liquid carbonate phase, ascertained by P. J. Wyllie, O. F. Tuttle, and R. I. Harker in the system calcitewollastonite-water at temperatures between 640° and 680° C. seems to be realized likewise under natural conditions, and to provide a basis for the understanding of certain phenomena, especially in reaction zones.

The fossils, which will be described hereafter by Dr. Günther, F.R.S., Prof. T. Rupert Jones, F.R.S., H. Woodward, F.R.S., and H. B. Brady, F.R.S., were found in the years 1873 and 1874 partly in rocks of the “Padangsche Bovenlanden” (Highlands of Padang), Government of the West Coast of Sumatra, and partly in marls and limestones of the Island of Nias.

Summary. A rare and typically Lower Riphean stromatolite Plicatina is reported from the Indian subcontinent for the first time. Elsewhere, its only well-known report is from the Lower Riphean rocks of Morocco. The present form has been identified as Plicatina misrai, a new form-species. It occurs in the thick calcareous Kapkot Formation, which is a practically unfossiliferous and widespread rock unit of the Lesser Himalaya. The present report has wider implications in many aspects, especially in raising the level of confidence in assigning a definite age to the rock unit in which it occurs.

The relations of the various rocks of the district lying to the North and South of Nuneaton have already been discussed by Prof. Lapworth from the data afforded by investigation in the field. He put into my hands many specimens of the different rocks for the purpose of microscopical examination. I have also received specimens from Mr. W. J. Harrison, and have collected some myself. Mr. J. J. H. Teall has also placed at my disposal a number of slides which he has had prepared from material of his own collecting.

The object of this paper is to bring before the notice of those interested a number of examples of spherulitic structures which seem to throw some light on the nature of the processes by which spherulites, lithophysae, and pyromerides are formed.

In a collection of Coal-measure Vertebrata made by Mr. J. Ward, of Longton, and recently acquired by the British Museum, there is an imperfect, crushed skeleton of a small Labyrinthodont from the Ash-coal Shale of Longton Hall Colliery, Staffordshire. This specimen was noticed by Miall in 1874 in his British Association Report on the Classification of the Labyrinthodonts, where it is referred to Urocordylus, some of the characters given in his diagnosis of that genus being taken from it. Some measurements of the skull were added. The same specimen was afterwards figured in Mr. Ward's paper “On the Geological Features of the North Staffordshire Coal-field” (Trans. N. Staffs. Instit. Mining Engineers, vol. x. 1890, pl. ix. fig. 2) as Keraterpetum Galvani. This figure, which is natural size, unfortunately does not show any details of the structure of the skull, some account of which may be of interest.

In bringing the last of a long series of papers on the Surface Drifts of the Lake District of Cumberland and Westmoreland to a close, Mr. Mackintosh sums up the general results at which he has arrived. All will agree with the first of his conclusions, “that land-ice may have planed, smoothed, polished, and striated rock surfaces, and pushed loose débris forward….” But I cannot see his reason for adding, “to the nearest protected situations,” for one would expect to find a terminal moraine at the open entrance of a valley, on a plain, or even on what can be proved to have been a true sea-bottom.

Heliolites caespitosa Salter (1873) is shown to be identical with Heliolites parvistella Roemer (1861) var. intricate Lindström (1899). The varietal name must, therefore, become caespitosa. Evidence is brought forward to suggest that the two varieties of this coral are the results of differing environments.