B. Mountain Limestone Proper.—Both the Hecla Hook and Liefde Bay strata, and the strata included in the foregoing division, consist of fresh-water formations, devoid of any trace of marine fossils; which proves that Spitzbergen, during the immense period of time in which these strata were deposited, formed a considerable continent. Later, however, these circumstances were altered, inasmuch as that part of the globe was again covered by sea, from which, with only an inconsiderable, perhaps local, break (the strata of the Coal-formation in Bell Sound), during a long sequence of geological periods, strata of great extent, containing marine fossils, were deposited. The oldest and most extensive of these strata belong to the Mountain Limestone formation, which in this part of the polar regions is specially developed and rich in fossils.

The Central-Southern Apennines are the result of the collision between Europe and Africa. Despite the volume of existing literature, many problems remain unsolved such as the presence of Tertiary conglomerates containing exotic basement clasts. The lack of basement rocks in the Central-Southern Apennines implies that the origin of these clasts has to be sought in areas where the basement is extensively exposed. These include the Calabro–Peloritani arc and the Sardinia–Corsica block, which in Cenozoic time were connected to the Central-Southern Apennines. In this work we present the results of sedimentary, geochemical and petrographic analyses performed on the exotic basement-derived clasts. These analyses include lithological, major- and minor-element and rare Earth element compositions which are compared to analogous rocks from Calabria and Sardinia basements. Results indicate Eastern Sardinia as the primary source area for the studied conglomeratic units, linking the Central-Southern Apennines sedimentary cover to the Mesozoic carbonates of Eastern Sardinia prior to the opening of Tyrrhenian Sea. The Cilento unit (Campania) was directly fed by an uplifting Cenozoic orogen, and the Filettino, Gavignano (Latium) and Ariano Irpino (Campania) units were produced by the successive reworking of ‘Cilento-like’ sedimentary units. These results may imply that part of the Central-Southern Apennines represented a portion of the European margin of the Tethys.

Having lately had the privilege of visiting several of the Continental Museums containing collections especially of Palæontological importance, some notes will perhaps be acceptable upon the present aspect of that branch of the science in which the writer is particularly interested. Such a broad survey imparts so many new ideas, and leaves so many pleasant memories of Naturalists in the midst of their work, that it is impossible adequately to incorporate the results in any brief notice; but a few points at least seem to be of general interest.

Álvaro et al. (2018) argued that at least six species of Acadoparadoxides described from the lower–middle Cambrian boundary interval successions in the Anti-Atlas of Morocco all belong to Acadoparadoxides mureroensis (Sdzuy, 1958), which was first described from the Iberian Chains, Spain. Their study is based entirely on a morphometric analysis, which ignores the stratigraphic occurrences of particular morphotypes, deformation-related compaction of individual sclerites and their original relief, and thus underestimates some of the earlier described differences between these species. Their synonymization of a number of named Acadoparadoxides species is based on the morphometric approach that they rely on to distinguish between a number of congeneric species. A morphometric approach as applied by Álvaro et al. will lead to an apparent synonymy based on sclerites of similar taxa. Thus, morphometric study must be complemented by an analysis of which morphologically distinctive sclerites (i.e. cranidia and pygidia) are stratigraphically associated, and evaluation of which measurements are more critical to distinguishing sclerites that may represent distinct taxa, and the recognition of related character sets. Apart from demonstrating problems in the conclusion of Álvaro et al., our more inclusive approach of morphologic and stratigraphic analysis works to reassert the diagnostic characters and differences between six earlier named species of Acadoparadoxides. Our conclusions also emphasize the taxonomic problems associated with the identification and morphological variation of A. mureroensis owing to tectonic deformation of its topotype material and to questionable taxonomic assignment of Acadoparadoxides specimens from the Iberian sections.

The appraisal and development of fractured reservoirs are challenging tasks because of the combined variations in reservoir quality and natural fracture distribution. Fracture models are built routinely to support both appraisal and development decisions for such reservoirs. One of the key objectives of these models is to generate three-dimensional (3D) fracture properties for dynamic flow simulations. In this paper, we illustrate the discrepancy between the scale of observation required to build a thorough geological understanding of the subsurface and the simplification imposed by modelling. We use a case study carried out in the context of an exploration campaign of a Cretaceous carbonate reservoir in Egypt. After describing the regional geological setting of the area, we share a series of detailed observations on open-hole logs, cores, thin-sections and borehole images. These observations are focused on reservoir architecture, fracture typology and fracture connectivity. Observations are then integrated with the regional geological context to build a conceptual fracture model and to characterize the uncertainty affecting the essential parameters of this model. The conceptual model, combined with 3D seismic data, is used to define a fracture modelling strategy. This strategy includes a drastic simplification of the conceptual model to generate 3D discrete fracture network scenarios that are calibrated using pressure communication data from the exploration wells. Another extreme simplification is then necessary to populate 3D simulation grids. In the case study presented, the key tuning parameters to obtain a dynamic match are the grid cell orientation and the width of the modelled fault damage zone.

The block of stone in question, like another exhibited by Mr. A. B. Wynne, was obtained by Dr. Warth, at Chel Hill, in the Punjab Salt Range. This specimen was sent by Dr. Warth to Mr. H. B. Medlicott, Director of the Geological Survey of India, who forwarded it to the present writer, in the hope of learning the views of those who have most experience of similarly marked boulders, and of ascertaining whether the peculiar characters of the present specimen are due to any particular form of ice action or to any other agency.

This note records a unique instance of rhythmic layering which is likely to have an important bearing on the interpretation of such layering in general.

The specimen here figured is a typical example of Actinostroma clathratum. In all its general characters, and particularly in the regular development of the radial pillars and the presence of small astrorhizas, it resembles the specimens from the Middle Devonian of Germany, which may be regarded as the normal form of the species. Very similar examples, however, occur in the Devonian Limestones of Devonshire. The surface of the specimen is not shown, being concealed beneath a crust of Stromatoporella Eifeliensis.

In the course of collecting in the Ballycastle coalfield, the species described in this note were obtained. Details of the associated fauna will be found in the forthcoming memoir of the Geological Survey of Ireland relating to the district. It is only necessary to, mention here that the beds from which the present material comes are, in the memoir, referred to a D2 horizon.

The material to be described was collected in the Shotts-Newhouse area (Sheet 31) of the Central Coalfield from the mussel bands above the Shotts Gas and presumed Lower Drumgray Coals. These horizons are within the Ovalis Zone (Weir and Leitch, 1936, pp. 704, 707). Fossils from above the presumed Lower Drumgray Coal were collected from the waste tip of South Langridge Colliery; material from the Shotts Gas was obtained from the tips at Fortissat, Hassockrigg, and Hirstrigg collieries.

The mafic and felsic Haertaolegai intrusions crop out in Urad Zhongqi, western Inner Mongolia and are dominated by monzogranite, porphyritic granite, and gabbroic diorite intrusions. We investigate the tectonic setting, geochronology, and anorogenic characteristics of the western Inner Mongolia through field investigation, microscopic and geochemical analyses of samples from the Haertaolegai bimodal intrusions and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) zircon U–Pb dating of gabbroic diorite and adakitic granites. Petrographic and geochemical studies of the bimodal intrusions indicate that the gabbroic diorites formed from a primary magma generated by the partial melting of lithospheric mantle material that had previously been modified by subduction-related fluids. The felsic rocks are high-K calc-alkaline and metaluminous, have characteristics of adakitic rocks and were generated during the partial melting of juvenile crustal material. Zircon U–Pb dating indicates that the felsic portion of this pluton was emplaced during late Carboniferous – early Permian time, with the mafic portion of the pluton emplaced during early Permian time. The zircons of adamellites have ɛHf(t) values and TDM2 ages of +1.0 to +2.7 and 1032–1128 Ma, respectively, suggesting that they formed from magmas generated by partial melting of juvenile Mesoproterozoic lower crust. These data, combined with the geology of the region, indicate that the late Carboniferous – early Permian bimodal intrusive rocks in western Inner Mongolia record a transitional period from collisional compression to post-collisional extension. These results indicate that the Paleo-Asian Ocean in western Inner Mongolia closed before 300 Ma.

A new fossiliferous section in the Coralline Crag of Suffolk is described, and its fauna is analysed as a clue to the conditions under which these beds were formed; in particular, the theory that the temperature of the Crag sea was affected by the alternate breaching and closing of land-bridges to the north and south of the North Sea area is considered unnecessary to account for the facts as seen in the field. Further, the Coralline Crag is correlated with the Astian formation of the Mediterranean, and reasons are brought forward to show that the supposed “Boytonian” Zone of the Coralline Crag does in fact not exist.

IN the January number of this Magazine there appeared a rejoinder by Messrs. Kitchin and Pringle to observations published by myself on their reading of the stratigraphical position of the Hunstanton Red Rock and its relation to the beds above and below. Since the following is intended as an answer to this, it is almost inevitable that it should be written in the first person. For this unavoidable egotism apologies are offered to readers.

‘Lower Old Red Sandstone’ deposits preserved by cauldron subsidence at Glen Coe, Scotland have hitherto lacked secure biostratigraphical age constraint. A sporomorph assemblage recovered from basal sediments of these deposits permits age determination, despite being highly carbonized. The sporomorph assemblage is correlated with the micrornatus-newportensis Sporomorph Assemblage Biozone, indicating a late early-early late Lochkovian age (early Devonian). Sporomorph assemblages from basal sediments of the ‘Lower Old Red Sandstone’ sequence at nearby Lorne, a suggested correlative of the Glen Coe deposits, are older (latest Pridoli-earliest Lochkovian age). However, the new biostratigraphical data do not preclude the possibility that the Glen Coe and Lorne deposits are lithological correlatives and the basal sediments are diachronous.

This paper gives the results of investigations made during the early part of the present year with the object of elucidating the relation of the Coal-measures to the Lower Carboniferous rocks in the Clapton and Clevedon districts of Somersetshire.