Conodont faunas from the Eoplacognathus pseudoplanus Zone in five main areas of Middle Ordovician rocks in Sweden are described and discussed and compared with faunas of comparable age from neighbouring areas. The investigation is based on 118 samples which together yielded 175 114 conodont elements. The Swedish conodont faunas are intermediate between shallower-water faunas from the eastern part of Baltica and deeper-water faunas towards the west. Correlation with the Yangtze platform of south-central China is fairly easy, and the occurrence of key taxa, such as Histiodella, makes it also possible to correlate some levels with Laurentia. Although faunal lists for the Swedish localities are almost identical, the conodont taxa have their relative abundance maxima in separate areas: species of Protopanderodus and Periodon are most common in deeper-water settings, Eoplacognathus, Baltoniodus and Microzarkodina characterize intermediate areas, and Semiacontiodus is typical of shallow subtidal environments

Amphigraptus divergens Lapworth is known to be restricted, in Britain, to the linearis Biozone, and its occurrence in the type Ashgill Series reinforces Rickards' prior independent attribution of that part of the type Ashgill to the linearis Biozone. The thecal structure revealed in this paper allies A. divergens to the dicellograptids rather than the leptograptids, hence it is placed in the family Dicranograptidae. The evolutionary origin of Amphigraptus is almost certainly rooted in Dicellograptus.

Quartz-rich xenoliths hosted in the basaltic–andesitic and andesitic lavas of Monte dei Porri, in the island of Salina, contain fluid and melt inclusions whose study makes it possible to trace back the magma ascent path of this volcano; moreover, they are a source of information about the anatectic processes that occurred under this island. The texture, mineralogy and whole-rock chemistry of these rocks exhibit the typical characteristics of a residual rock which went through several melt extraction events. The chemistry of melt inclusions hosted inside quartz grains (SiO2>72.7%, Al2O3=9.0–13.5%, CaO=0.2–4.3%, K2O>3.1%, MgO, FeOt≤1.5%) supports the hypothesis that a progressive and continuous anatectic processes affected a peraluminous high-grade metamorphic rock (gneiss or micaschist), that constituted the Calabro–Peloritani basement and generated a quartz-bearing residue. The fluids trapped inside these inclusions are rarely composed of high-density CO2, with a homogenization temperature to liquid phase (ThL) within the range 26.2–31.0°C, corresponding to densities of 520 to 690 kg/m3. More commonly, they are made up of low-density CO2, with a homogenization temperature to vapour phase (ThV) within the range 13.2–31.0°C, corresponding to density values of 150 to 460 kg/m3. It is proposed that, during ascent, batches of magma rising from the mantle sampled various fragments of a residual rock from a depleted metamorphic basal layer and carried them to the surface. Magmas probably stopped inside at least two distinct reservoirs located at different depths (≤12.7 km and between 1.7 and 4.7 km), in which they underwent fractional crystallization. The ascent speed of the xenolith-bearing magmas from the deeper storage area to the shallower reservoir was fairly high, as confirmed by the low number of high-density fluid inclusions preserved that show re-equilibration features, and by the contemporaneous presence of denser cumulitic Ol+Cpx±Opx xenoliths in the host lava.

The aim of this study is to describe the biostratigraphic, chronostratigraphic and ecostratigraphic relationships of the Neogene sequence in the Adana Basin. The Adana Basin is located in southern Turkey, and bordered by the Tauride Orogenic Belt to the north, the Amanos Mountains to the east, the Mediterranean coast to the south and the Ecemiş Fault Zone to the west. From base to top, the Neogene sequence consists of the Gildirli Formation (continental redbeds), the shallow marine Kaplankaya Formation, the reefal limestones of the Karaisalı Formation, the shales of the Güvenç Formation (slope to deep marine), a thick submarine fan complex (Cingöz Formation), the shallow marine and fluvio-deltaic Kuzgun Formation and the shallow marine lagoonal–continental Handere Formation. The planktonic foraminiferal biozones identified within the Neogene sequence of the Adana Basin are Globigerinoides trilobus and Praeorbulina glomerosa curva (Burdigalian), Globorotalia fohsi peripheroronda/Orbulina suturalis (Langhian), and Globorotalia mayeri (Serravallian). The Late Tortonian is characterized by the first occurrence of Globorotalia suterae. There are no planktonic foraminiferal zones in the Messinian, but this level may be correlated with a non-distinctive zone in the Mediterranean region. The Pliocene is represented by the Sphaeroidinellopsis Acme Zone.

The Strathy Complex of the Scottish Caledonides is a bimodal association of amphibolites and siliceous grey gneisses that structurally underlies adjacent metasediments of the Moine Supergroup. Both rock units record a common polyphase Caledonian tectonometamorphic history. New elemental and radiogenic isotope data indicate that both end-members of the Strathy suite were derived from a depleted mantle source, that they are cogenetic and that they may have been related by crystal fractionation. δ18O values and their correlations with major and trace elements suggest that the protoliths were hydrothermally altered at temperatures below 200 °C. Tectonomagmatic discrimination based on relatively immobile elements and isotope systems, plus comparison with geochemically similar bimodal supracrustal associations elsewhere, strongly support the conclusion that the igneous protoliths of the Strathy Complex formed in an oceanic destructive margin setting. If TDM model ages of c. 1000 Ma approximate protolith crystallization, the Strathy Complex may have formed as juvenile crust in the peri-Rodinian ocean broadly contemporaneous with the Grenville orogenic cycle.

The supergiant Shizhuyuan W–Sn–Bi–Mo deposit is hosted by the Qianlishan granite, a small, highly fractionated granitic pluton (∼10 km2) with multiple phases of intrusions within the Early Yanshanian granitoid province of SE China. Strong alteration of skarn and greisen that formed in the contact zone between the first and second phases of granite intrusions and Devonian limestone is responsible for the polymetallic mineralizations. SHRIMP U–Pb zircon analysis indicates that the two early phases of the Qianlishan granite formed contemporaneously at 152±2 Ma. Metasomatic minerals (garnet, fluorite and wolframite) separated from the skarn and greisen yield a Sm–Nd isochron age of 149±2 Ma that is interpreted as the formation age of the Shizhuyuan deposit. Therefore, the mineralization of the supergiant Shizhuyuan polymetallic deposit formed contemporaneously with, or very shortly after, the intrusion of the small, highly fractionated Qianlishan granite.

In many cases, when dealing with argillaceous fine-grained sedimentary rocks, the isotopic ages obtained from Rb–Sr whole-rock isochron calculations are of geological significance, despite the fact that the initial conditions of Sr isotopic homogenization are not fulfilled. To explain this, a mechanical mixing during deposition has been suggested, leading to an aggregate of mixed material with fairly uniform 87Sr/86Sr values, whatever Rb/Sr ratio is found in the analysed samples. This investigation of the behaviour of Rb and Sr during sedimentation and early diagenesis, involves study of more than 60 samples of fine-grained recent sediments from selected coastal localities of Brazil. The results indicate that pelitic samples from some recent to present-day transitional or shallow marine environments, such as the Jacarepaguá tidal flat and the Amazonas River mouth, where halmirolysis could have occurred, may produce nearly horizontal best-fit lines in a Rb–Sr isochron diagram. Moreover, the initial isotopic 87Sr/86Sr ratios appear to be well above 0.710. In open marine environments, such as the Campos Basin, where sampling was spread over more than 100 metres, exchanges between the argillaceous sediments and seawater potentially happen at low temperature, inducing a reduction of the 87Sr/86Sr isotopic composition of the sediments to nearly 0.710. An almost horizontal best-fit line is produced for the entire stratigraphic section, independent of the sedimentation age. We believe that in similar environments such ‘zero age isochrons’ are maintained for some time, testifying to exchanges between the sediment and the interstitial fluids, before the onset of burial diagenesis. The above described studies on fine-grained and recent argillaceous sediments seem to confirm the production of horizontal best-fit lines in isochron diagrams, justifying the application of the Rb–Sr whole-rock method to pelitic sedimentary rocks. The nature of the material is critical. The pelitic sediments to be analysed should contain only very limited amounts of coarse clastic material (especially feldspars and mica fragments) and consist mainly of fine clay minerals in which smectites, illite and mixed layers illite–smectite largely predominate.