Burmese amber continues to provide unique insights into the terrestrial biota inhabiting tropical equatorial forests during mid-Cretaceous time. In contrast to the large amount and great diversity of terrestrial species retrieved so far, aquatic biota constitute rare inclusions. Here we describe the first freshwater snail ever preserved in amber. The new species Galba prima sp. nov. belongs in the family Lymnaeidae, today a diverse and near globally distributed family. Its inclusion in terrestrial amber is probably a result of the amphibious lifestyle typical of modern representatives of the genus. The finding of a freshwater snail on the Burma Terrane, back then an island situated at some 1500 km from mainland Asia, has implications for the dispersal mechanisms of Mesozoic lymnaeids. The Cenomanian species precedes the evolution of waterfowl, which are today considered a main vector for long-distance dispersal. In their absence, we discuss several hypotheses to explain the disjunct occurrence of the new species.

The Carrai Granodiorite is an intrusive magmatic pluton with steeply dipping margins surrounded by a well-developed contact metamorphic aureole. Emplacement of the body was accompanied by little distortion of neighbouring rocks and involved vertical displacement of pre-existing material. Scarcity of country rock blocks, and the presence of numerous dioritic xenoliths indicate that stoping was unimportant, and the pluton was accommodated in the upper crust by vertical uplift of earlier rocks (‘block elevation’). A close relationship existed between faulting and granodiorite emplacement. Deep shears possibly account for the generation of the linear zone of plutons in which the Granodiorite is located.

Myanmar is occupied by the N-wards continuation of the Sunda arc and by the Shan Plateau and its continuation through Yunnan into Tibet. Our new tectonic interpretation of the ophiolite–flysch belts, world-famous jadeite and tin deposits in Myanmar west of the Salween adopts previous proposals that, before 450-km post-early Oligocene dextral displacement along the Sagaing Fault, the ophiolite belt in NE Myanmar continued through the topography that is now located west of the fault in the Indo-Burman Ranges. Differences in cross-section through Mogok and the Shan Scarps are reconciled by the recently proposed emplacement, in our view during Permian time, of the Mogok Metamorphic Group onto the Slate Belt to form Sibumasu. We argue that during Early Jurassic time a Neo-Tethys ophiolite nappe was obducted over turbidites on Sibumasu’s passive western margin. Following reversal in tectonic polarity, the remaining Neo-Tethys subducted E-wards generating the 113–128 Ma Mondaung Arc. During ocean closure the Victoria–Katha Block and its Triassic flysch subducted beneath Sibumasu, resulting in jadeite veins in overlying serpentinite that ascended in the subduction zone and were exhumed at Hpakant and Nat Hmaw, bordering the Jade Mines Uplift. Subduction of the Indian Ocean since Albian time generated the Popa–Loimye arc, while extensional faulting led to uplift of the Indo-Burman Ranges and to the formation of the Western Tin Belt granites. Tectonic effects in Myanmar of the India–Asia collision may be confined to the Disang thrust belt in the Naga Hills.

The Castejón-Laspaúles basin is one of the South Pyrenean basins of Late Variscan age that were strongly inverted during the Alpine compression (Late Cretaceous–Tertiary). It is mainly composed by Stephanian pyroclastic and volcanic deposits that reach a maximum thickness of ~ 500 m, and are overlain by Permian and Triassic sedimentary units. A palaeomagnetic and magnetic fabrics (AMS) study was carried out in the Stephanian units, where the general absence of flow markers at the outcrop scale and the Alpine inversional structure prevent the straightforward reconstruction of the original volcanic and basinal configuration. Magnetic fabric data are not overprinted by Alpine internal deformation and can be interpreted in terms of primary volcanic and pyroclastic fabrics. The obtained directions coincide in the different sampled units, suggesting a constant source area during the development of the basin, and show the dominance of N–S-trending K1 axes that are interpreted to be parallel to flow directions. Palaeomagnetic data indicate the presence of a pre-folding palaeomagnetic component that is rotated clockwise by an average of +37° (±32°) with regards to the Stephanian reference. This rotation probably took place during Alpine thrusting since it is also registered by the overlying Triassic deposits. The whole dataset is interpreted in terms of basin development under sinistral transtension with two main fault sets: deep-rooted E–W-striking faults, probably responsible for magmatic emissions, and shallow-rooted, listric faults of N–S orientation.

The Early Palaeozoic Shuanggou ophiolite is the best-preserved part of the Ailaoshan ophiolite belt. The microgabbros (basaltic dykes) and basalts (basaltic lavas) show distinct characteristics in geochemistry, implying that their genetic mechanisms are different. With Al2O3 contents ranging from 14.7% to 17.0%, the microgabbros belong to low-alumina type. They exhibit normal mid-ocean-ridge basalt (N-MORB) -like trace elemental characteristics with positive εNd(t) values (9.7–11.6) and slightly variable (87Sr/86Sr)i ratios (0.7036–0.7046). In contrast, the basalts have high Al2O3 contents (19.5–23.2%), therefore belonging to high-alumina type. A plagioclase-accumulation model is used to account for the high alumina contents. Moreover, the basalts have enriched MORB (E-MORB) -like trace element characteristics with lower εNd(t) values (6.4–8.0) and (87Sr/86Sr)i ratios (0.7032–0.7036). Their incompatible element ratios exhibit linear correlation with the isotopic data, which is probably related to the contribution of a mixed lithosphere–asthenosphere source. In summary, a two-stage model is proposed to explain the formation of the Shuanggou ophiolite: (1) at the continent–ocean transition stage, the basalts were generated by low-degree partial melting of the mixed mantle near a slow-spreading embryonic centre; and (2) at the mature stage of the Ailaoshan Ocean, the microgabbros were produced by moderate-degree partial melting of the depleted asthenospheric mantle.

The palaeoproterozoic Svecofennian orogen in southern Finland contains a number of orogenic gold occurrences. The Jokisivu gold deposit, comprising auriferous quartz veins, is hosted by syn-tectonic quartz diorites to gabbros. Mineralization occurs in approximately WNW–ESE- and WSW–ENE-trending shear zones, which probably branch from regional-scale NW–SE-trending shears. Ore zone fabrics post-date regional-scale folding and the metamorphic peak, and can be correlated with late Svecofennian regional shear tectonics (D6; 1.83–1.78 Ga), indicating that mineralization formed during the late stages of orogenic evolution. SIMS and TIMS U–Pb dating of three samples place tight constraints on the age of gold mineralization. Zircons from both unaltered and altered quartz diorites have ages of 1884±4 Ma and 1881±3 Ma, respectively. These are interpreted as the crystallization age of the rock and as providing the maximum age for mineralization. Zircon rims from an altered quartz diorite from the ore zone give ages of c. 1802±15 Ma, which overlap with the 1801±18 Ma titanite (mean Pb–Pb) age from the ore zone. The ages are similar to the age of the pegmatite dyke that cuts the ore zone and whose zircon age of 1807±3 Ma is approximately the same as the 1791±2 Ma monazite age (TIMS) giving the minimum age of the gold mineralization. The mineralization and its structural framework can be correlated with coeval late Svecofennian shear tectonics related to WNW–ESE-oriented shortening in southern Finland. Extensive c. 1.8 Ga granite magmatism, shear zone development and associated gold mineralization are of regional importance also in the northern and western Fennoscandian Shield (Finnish Lapand and Sweden). A Cordilleran-type setting can explain the widespread distribution of magmatism and gold mineralization associated with shortening, as well as the required heat source triggering hydrothermal fluid flow along shear zones.

In Connemara and South Mayo, three main rock groups have been distinguished. The first group, largely developed in South Mayo (see sketch-map), consists of slates, phyllites, grits, conglomerates and thin limestones, and, although these rocks are much cleaved, sufficient fossils have been found to prove that they vary in age from Arenig to Ludlow. The second group of rocks, occurring principally in northern Connemara, consists essentially of quartzites, limestones and schists, and in this group fossils have not been found. In the pelitic schists of this group, biotite, garnet, staurolite and fibrous sillimanite are of widespread occurrence, proving that the group as a whole is in a state of medium to high grade regional metamorphism. We propose that the term Connemara Schists, which has previously only been used vaguely, should be restricted to this group. The third group, occurring in Southern Connemara, is a gneissic series which was tentatively correlated with the Lewisian Gneiss by early workers, and which is indeed remarkably similar to it in general appearance. Later work by Callaway (1887) and McHenry (1903) has, however, shown that these gneisses are not overlain unconformably by the Connemara schists, but are orthogneisses intrusive into them. Their age, therefore, relative to the Connemara Schists, is not in doubt.

The Upper Cretaceous Kanguk Formation of the Sverdrup Basin, Canadian Arctic Islands, contains numerous diagenetically altered volcanic ash layers (bentonites). Eleven bentonites were sampled from an outcrop section on Ellesmere Island for U–Pb zircon secondary ion mass spectrometry dating and whole-rock geochemical analysis. Two distinct types of bentonite are identified from the geochemical data. Relatively thick (0.1 to 5 m) peralkaline rhyolitic to trachytic bentonites erupted in an intraplate tectonic setting. These occur throughout the upper Turonian to lower Campanian (c. 92–83 Ma) outcrop section and are likely associated with the alkaline phase of the High Arctic Large Igneous Province. Two thinner (<5 cm) subalkaline dacitic to rhyolitic bentonites of late Turonian to early Coniacian age (c. 90–88 Ma) are also identified. The geochemistry of these bentonites is consistent with derivation from volcanoes within an active continental margin tectonic setting. The lack of nearby potential sources of subalkaline magmatism, together with the thinner bed thickness of the subalkaline bentonites and the small size of zircon phenocrysts therein (typically 50–80 μm in length) are consistent with a more distal source area. The zircon U–Pb age and whole-rock geochemistry of these two subalkaline bentonites correlate with an interval of intense volcanism in the Okhotsk–Chukotka Volcanic Belt, Russia. It is proposed that during late Turonian to early Coniacian times intense volcanism within the Okhotsk–Chukotka Volcanic Belt resulted in widespread volcanic ash dispersal across Arctic Alaska and Canada, reaching as far east as the Sverdrup Basin, more than 3000 km away.

Pegmatites and associated granitoids are integral parts of the Alvand plutonic complex in the Sanandaj–Sirjan zone, Iran. Whole rock major- and trace-element lithogeochemistry together with zircon U–Pb geochronology and zircon geochemistry are examined to evaluate the petrogenesis of sapphire-bearing pegmatites and other peraluminous pegmatites in the region. Pegmatites vary in their chemical compositions from mostly peraluminous, high-K calc-alkaline to shoshonitic signatures. A rare variety of extremely peraluminous sapphire-bearing syenitoid pegmatite (Al2O3 > 30 wt %; A/CNK > 2) exists. This silica-undersaturated pegmatite and its sapphire crystals have a primary igneous origin. U–Pb zircon geochronology of three separate samples from this pegmatite indicates the following ages: 168 ± 1 Ma, 166 ± 1 Ma and 164 ± 1 Ma. The zircon grains have notable amounts of Hf (up to 17 200 ppm), U (up to 13 580 ppm), Th (up to 5148 ppm), Y (up to 4764 ppm) and ∑REE (up to 2534 ppm). There is a positive correlation between Hf and Th, Nb and Ta, U and Th, and Y and HREE and a negative correlation between Hf and Y values in the zircons. These zircons exhibit pronounced positive Ce anomalies (Ce/Ce* = 1.15–68.06) and negative Eu anomalies (Eu/Eu* = 0.001–0.56), indicative of the relatively oxidized conditions of the parent magma. Ti-in-zircon thermometry reveals temperatures from as low as ~683 °C up to ~828 °C (average = 755° ± 73 °C). Zircon and monazite saturation equilibria are also consistent with these temperatures. Zircon grains are magmatic (average La < 1.5, (Sm/La)N > 100 and Th/U > 0.7), with chemical characteristics similar to zircons from continental crust.

We investigate the phased evolution and variation of the South Asian monsoon and resulting weathering intensity and physical erosion in the Himalaya–Karakoram Mountains since late Pliocene time (c. 3.4 Ma) using a comprehensive approach. Neodymium and strontium isotopic compositions and single-grain zircon U–Pb age spectra reveal the sources of the deposits in the east Arabian Sea, and show a combination of sources from the Himalaya and the Karakoram–Kohistan–Ladakh Mountains, with sediments from the Indian Peninsula such as the Deccan Traps or Craton. We interpret shifts in the sediment sources to have been forced by sea-level changes that correlate with South Asian monsoon rainfall variation since late Pliocene time. We collected 908 samples from the International Ocean Discovery Program Hole U1456A, which was drilled in the east Arabian Sea. Time series of hematite content and grain size of the sediments were examined downcore. We found South Asian monsoon precipitation and weathering intensity experienced three phases from late Pliocene time. Lower monsoon precipitation, with a lower variability and strong weathering intensity, occurred during 3.4–2.4 Ma; an increased and more variable South Asian monsoon rainfall, along with strengthened but fluctuating weathering intensity, occurred at 1.8–1.1 Ma; and a reduced rainfall with lower South Asian monsoon precipitation variability and moderate weathering intensity marked the period 1.1–0.1 Ma. Maximum entropy spectral analysis and wavelet transform show that there were orbital-dominated cycles of periods c. 100 and c. 41 ka in these proxy-based time series. We propose that the monsoon, sea level, global temperature and insolation together forced the weathering and erosion in SW Asia.

The skeleton of a new vauxiid sponge (Order Verongida), Angulosuspongia sinensis gen. et sp. nov., described on the basis of material from calcareous mudstones of the Kaili Formation (Cambrian Stage 5), Jianhe area, Guizhou, South China, is composed of two layers of fused spicules outlining hexagonal or polygonal openings. These vauxiid remains are the first reported from outside Laurentia, and represent only the second genus attributed to the family. Its age is close to but still slightly older than the Burgess Shale Biota, and it appears to be a primitive relative of other members of the Vauxiidae. The morphological differences between Chinese and Laurentian vauxiid sponges may be a result of vicariance. These specimens not only extend the geographic distribution of vauxiids, but also help to fill a chronostratigraphical gap between North Greenland and North American material and provide additional evidence for understanding the evolutionary history of the Demospongiae.

Mammalian remains are reported from a Pleistocene terrace deposit in the lower Derwent Valley near Derby, which is a correlative of the Beeston Terrace of the nearby River Trent. The faunal assemblage is characteristic of the Ipswichian interglacial and compares favourably with previous finds at other Ipswichian sites in southern Britain. The discovery is significant as it provides the strongest evidence so far for a dating of the Beeston Terrace which is critical to the Pleistocene chronology of the region.

Chemical analyses and petrographic data are given of the eastern granites of the Mourne Mountains. It is shown that the main bulk of the granite is a uniform highly siliceous biotite-bearing type and that the intrusion of this was preceded by a smaller amount of less siliceous and more variable hornblende-bearing granite. The ferromagnesian minerals have a high iron to magnesium ratio.

By systematic sampling (including the drilling of orientated cores) new data are presented on the chemistry, petrography, mineralogy, K/Ar isotopic age and remanent magnetism of the Wolf Rock, Cornwall. The overall homogeneity of the Rock is confirmed as a fine-grained fluxioned microporphyritic phonolite. Major joints strike NNW–SSE and NNE–SSW and there is a pronounced floor jointing. New whole-rock and probe analyses of the constituent minerals are given. Nosean, previously recorded, is found to be replaced by analcime, cancrinite and other minerals. K–Ar determinations on nepheline and K-feldspar give mean ages of 112±2, and 130±6 Ma respectively. The mean pole position of 70° N, 6° E, suggests that the 130 Ma pole for stable Europe may have been somewhat closer to Europe than previously supposed. The significance of this Lower Cretaceous magmatism in the context of Mesozoic volcanism in Southern England and European alkaline provinces is discussed.

From the short notices which are to be found about volcanos in treatises on geology, we might often be led into the belief that they were structures so regular in contour that their form was indicative of their nature. In certain cases this appears to be so remarkably true, that I wish to add a few observations to those which have already been written upon the subject. In other cases, however, the form of a volcano does not appear to have any characteristics which distinguish it from other mountains, as will be seen by glancing through the series of views given by Humboldt of the volcanos of South America. The mountains in Iceland are also very rough. When travelling in that country, where I saw and ascended many volcanos, I do not remember that there was anything about their shape more than their steepness and general ruggedness which particularly attracted my attention. The wilderness of form presented to us by such mountains as these is so evidently the combined effect of many and varied causes, that it would be vain to seek a simple explanation for the formation of the whole.

The invaluable Presidential Addresses by Professor H. H. Read, entitled “Meditations on Granite”, Parts I and II, read to the Geologists’ Association in 1943 and 1944, seem to have aroused a great deal of interest in petrological quarters, more especially as these “meditations” are painted against the lively background of the historical development of ideas embracing a whole century and a half. Professor Read’s “meditations” are the more remarkable since they lead him to conclusions almost diametrically opposed to those propounded by Professor P. Niggli in an address delivered to the Zürich Geological Society at the February meeting of 1942, although both reviewers rely on about the same scope of historical “evidence”.

Pleistocene silty mudflow deposits mantle much of the valley sides and floors of the Balcombe area of the central Weald. Boulder deposits at the foot of cliffs formed of resistant bedrock sandstones are also of Pleistocene age. One well sorted sand from a gentle valley side shows surface grain textures under the scanning electron microscope indicative of wind action. The superficial deposits formed under periglacial conditions, and their distribution indicates most of the landforms are relict Pleistocene features.

On the New Siberian Islands the rocks of the east Russian Arctic shelf are exposed and allow an assessment of the structural evolution of the region. Tectonic fabrics provide evidence of three palaeo-shortening directions (NE–SW, WNW–ESE and NNW–SSE to NNE–SSW) and one set of palaeo-extension directions revealed a NE–SW to NNE–SSW direction. The contractional deformation is most likely the expression of the Cretaceous formation of the South Anyui fold–thrust belt. The NE–SW shortening is the most prominent tectonic phase in the study area. The WNW–ESE and NNW–SSE to NNE–SSW-oriented palaeo-shortening directions are also most likely related to fold belt formation; the latter might also have resulted from a bend in the suture zone. The younger Cenozoic NE–SW to NNE–SSW extensional direction is interpreted as a consequence of rifting in the Laptev Sea.

Among the collections received from the Egyptian Survey for determination is a number of vertebrate remains, chiefly mammalian, from the Wadi-Natrun, whence they were obtained by Captain Lyons, the Director-General of the Survey, and by Messrs. Beadnell and Blanckenhorn, members of his staff. Last year, on my return from Mogara with Mr. T. Barron, I was able to collect for a few hours on the hill called Gart-el-Moluk, from which most of these fossils were obtained, and found a few additional fragments. Finally, Dr. Studer, of the Berne Museum, has very kindly lent me the collection he received from the same locality, and has himself described in some detail.1 I believe, therefore, that a great part of the specimens from this locality are now in my hands. Unfortunately in most cases the remains are in a very fragmentary condition and little can be made of them, but there are a few well-preserved teeth and limb bones which indicate the existence of a fauna of considerable interest, and are sufficient to show that the locality will probably yield good results to a systematic search. At present the collections include remains of a small Hippopotamus, a Hipparion, a small pig-like animal, and various Antelopes. In the present note I propose to give a short account of the more important of these specimens.