The Madagascar Cretaceous igneous province exposed in the Mahajanga basin is represented by basalt and basaltic andesite lavas. New 40Ar–39Ar plateau ages (92.3 ± 2.0 Ma and 91.5 ± 1.3 Ma) indicate that the magmatism in the Mahajanga basin started about 92 Ma ago. Four geochemically distinct magma types (Groups A–D) are present. Group A and C rocks have low to moderate TiO2 (1.2–2.6 wt%), Nb (3–9 μg g−1) and Zr (82–200 μg g−1), and show large variations in ɛNdi (+0.1 to −10.8), 206Pb/204Pb (15.28 to 16.33) and γOs (+11.4 to +7378). The large isotopic variations, particularly in Os, Nd and Pb isotopic compositions, are likely due to crustal contamination. The low Pb isotope ratios observed in the Group A and C rocks suggest involvement of continental crust with low μ (238U/204Pb). Group B and D rocks have moderate to high TiO2 (2.2–4.9 wt%), Nb (8–24 μg g−1) and Zr (120–327 μg g−1). Age-corrected isotopes of Group B and D lavas show a small range in ɛNdi (+1.0 to +4.0) and a wide range in γOs (+128 to +1182). Values of 207Pb/204Pb are within the range for Groups A and C, but the Group D 206Pb/204Pb (16.52–17.08) and 208Pb/204Pb (37.51–38.01) values are higher, indicating a different crustal contaminant. Pb isotopic values of the Group B rocks seem to reflect the isotopic features of their mantle source. The magma groups of Mahajanga display a wide range of trace element and isotopic compositions that cannot be explained only by open-system crystallization processes but, rather, by distinct mantle sources.

Mineralogical studies of a silicified serpentinite from the United Arab Emirates throw light on the formative processes. The silicified serpentinite is a residuum of a palaeo-weathering surface that probably developed in a temperate climate with alternating wet and dry periods during middle Eocene to late Miocene times. The rock textures indicate that silicification occurred in a fluid-saturated zone. Silica precipitation is favoured at near-neutral pH. In this study we infer that these pH conditions of the mineralizing fluids could arise in a near-surface mixing zone where acidic meteoric and hyperalkaline groundwater fluids are mingled. This mingling is believed to have resulted from alternating processes of evaporation and precipitation that prevailed during dry and wet seasons, respectively. The silicified serpentinite is composed of > 95% quartz and exhibits a ghost texture of the protolith serpentinite. Preservation of the textures indicates an iso-volumetric grain-by-grain replacement by dissolution of Mg-silicate and simultaneous precipitation of either opal or microquartz as siliceous seeds. These were subsequently overgrown by silica that was probably remobilized from deeply weathered regolith elsewhere.

The Lower Yangtze foreland basin is situated to the northwest of the early Palaeozoic Wuyi–Yunkai orogen in South China. To demonstrate its provenance history and the denudation of the orogen, seven sandstone samples were collected from the upper Ordovician to Silurian strata for U–Pb dating. The zircons show a broad range of ages that can be linked with the ages of specific units in the Wuyi–Yunkai orogen. The zircon spectra in the late Ordovician samples are similar to those in the pre-orogenic strata, suggesting a recycled source. The dominant age population of 880–740 Ma in the early Llandovery samples indicates that the middle Neoproterozoic volcanic rocks were the primary source. A significant age population of 460–425 Ma in the late Llandovery to Wenlock samples reflects the fact that the synorogenic magmatic and metamorphic rocks were exposed to provide detritus. The youngest zircons from the uppermost Silurian strata yield an age of 425 Ma, which approximates the inferred depositional age. This age, together with available biostratigraphic data, indicates that the foreland basin was formed 448–425 Ma ago. We surmise a possible link between the Wuyi–Yunkai orogen and the Appalachian–Caledonian orogen based on the geological constraints and palaeomagnetic data.

A distinct spatial relationship between surface faulting, magmatic intrusions and volcanic activity exists in the Aegean continental crust. In this paper, we provide detailed structural observations from key onshore areas, as well as compilations of lineament maps and earthquake locations with focal plane solutions from offshore areas to support such a relationship. Although pluton emplacement was associated with low-angle extensional detachments, the NNE- to NE-trending strike-slip faults also played an important role in localizing the Middle Miocene plutonism, providing ready pathways to deeper magma batches, and controlling the late-stage emplacement and deformation of granites in the upper crust. Additionally, the linear arrangements of volcanic centres, from the Quaternary volcanoes along the active South Aegean Volcanic Arc, are controlled primarily by NE-trending faults and secondarily by NW-trending faults. These volcanic features are located at several extensional settings, which are associated with the main NE-trending faults, such as (i) in the extensional steps or relay zones between strike-slip and oblique-normal fault segments, (ii) at the overlap zones between oblique-normal faults associated with an extensional strike-slip duplex and (iii) at the tip zone of a NE-trending divergent dextral strike-slip zone. The NE trend of volcano-tectonic features, such as volcanic cone alignments, concentration of eruptive centres, hydrothermal activity and fractures, indicates the significant role of tectonics in controlling fluid and magma pathways in the Aegean upper crust. Furthermore, microseismicity and focal mechanisms of earthquakes in the area confirm the activity and present kinematics of these NE- trending faults.

The Fenestella Shale Formation of Jammu and Kashmir Himalaya comprises latest Viséan or Serpukhovian siliciclastic deposits formed along the southern margins of the Palaeotethys Ocean. A sequence of shallowing upward and deepening upward units indicates changes from shoreface to offshore and deeper shelf conditions, probably controlled by eustatic changes in an otherwise passive depositional system. Some of the finer-grained, shallow marine deposits have yielded fossil floras dominated by sub-arborescent lycopsids (Sublepidodendron, Lepidodendropsis) sphenophytes (Archaeocalamites) and pteridophylls (Nothorhacopteris, Triphyllopteris). The assemblage compares with other Gondwanan floras of this age that have been assigned to the Paraca floral realm, and are taken to indicate relatively warm climatic conditions that existed just prior to the onset of the Carboniferous–Permian ice-age.

Psephophorus polygonus Meyer, 1847, the first fossil leatherback turtle to be named, was described on the basis of shell ossicles from the middle Miocene (MN6–7/8?) of Slovakia. The whereabouts of this material is uncertain but a slab on display at the Naturhistorisches Museum Wien is considered the neotype. We rediscovered further type locality ossicles in four European institutions, re-evaluated their gross morphology and described for the first time their microstructure by comparing them with Dermochelys coriacea, the only living dermochelyid turtle. The gross morphology is congruent with that already described for P. polygonus, but with two significant exceptions: the ridged ossicles of P. polygonus may have a distinctly concave ventral surface as well as a tectiform shape in cross-section. They do not develop the external keel typical of many ossicles of D. coriacea. Both ridged and non-ridged ossicles of P. polygonus are characterized by compact diploe structures with an internal cortex consisting of a coarse fibrous meshwork, whereas the proportionately thinner ossicles of D. coriacea tend to lose the internal cortex, and thus their diploe, during ontogeny. The ossicles of both P. polygonus and D. coriacea differ from those of other lineages of amniotes whose carapace is composed of polygonal ossicles or platelets, in having growth centres situated at the plate centres just interior to the external bone surface and not within the cancellous core or closer to the internal compact layer. The new diagnosis of P. polygonus allows us to preliminarily re-evaluate the taxonomy of some of the Psephophorus-like species. Despite some macro- and micromorphological differences, it seems likely that Psephophorus was as cosmopolitan as extant Dermochelys and had a broadly similar ecology, with a possible difference concerning the dive depth.

Parringtonia gracilis Huene, 1939 is represented by both cranial and postcranial material collected from the lower Middle Triassic (Anisian) Lifua Member of the Manda beds in southwestern Tanzania. This aberrant taxon was previously proposed to have affinities with pseudosuchian archosaurs, and specifically with the enigmatic Erpetosuchus granti from the Upper Triassic of Scotland. Here, we confirm the close affinities of Parringtonia gracilis and Erpetosuchus granti based on the following unambiguous synapomorphies: mediolaterally expanded posterior portion of the maxilla, alveoli present only in the anterior half of the maxilla, and absence of tooth serrations. Furthermore, the two taxa share osteoderms with deep sculpturing, a deep fossa on the dorsal margin of the neural spines and a heavily waisted shaft of the scapula. We added both Parringtonia gracilis and Erpetosuchus granti into a comprehensive phylogenetic analysis of early archosaurs and found that these taxa are clearly referable to Archosauria but that relationships are poorly resolved at the base of this clade. However, our analysis demonstrates that Erpetosuchus granti is not closely related to Crocodylomorpha, as has been hypothesized previously. The Erpetosuchidae are a clade of small-bodied archosaurs that have a poor fossil record but have members from both northern and southern Pangaea, ranging temporally from the Middle to Late Triassic. Thus, Erpetosuchidae is part of the early archosaurian radiation.

A comprehensive palaeoenvironmental reconstruction of the last 219 ka has been carried out by determining the isotopic signatures (δ18O and δ13C) in 766 samples of a thermogene travertine formation in the Guadix-Baza Tertiary basin (Granada, SE Spain). This travertine formation was dated from ≈ 220 to ≈ 5 ka by means of the alpha-spectrometry technique. Initially, the study of the δ18O values of the travertine formation was carried out because they are excellent indicators of the overall palaeoclimatic condition of a particular site. Likewise, the evolution of δ13C values, which can be directly related to the biomass development of the site, has also been studied. Finally, an integrated study of both isotopic records has been performed, identifying a total of 12 climatic periods based on their palaeoclimatic and palaeoenvironmental conditions. These periods are grouped into four climatic scenarios: scenario A, characterized by warm and dry periods; scenario B, characterized by cold and humid periods; scenario C, constituted by warm and humid periods; and scenario D, which is characterized by cold and dry periods. Palaeoclimatic scenarios A and B mainly characterized the palaeoclimatic evolution of the site, while in northern Europe the palaeoclimatic evolution is mainly characterized by scenarios C and D. Therefore, it is suggested that the palaeoenvironmental evolution at lower latitudes on the Iberian Peninsula is the opposite of that identified in northern Europe. However, the main climatic events identified at higher latitudes are also reflected in the studied area.

Jurassic mélange complexes related to the subduction of the Neotethys Ocean occur in the Bükk Mountains, North Hungary. This paper characterizes the sedimentary sequence of basin and slope facies that occur in the southwestern part of the Bükk Mountains, placing special emphasis on the redeposited sedimentary rocks (olistostromes, olistoliths: Mónosbél Group) in order to obtain information on the provenance of the clasts, and the mode and time of their redeposition. The series of formations studied shows a general coarsening-upwards trend. Based on radiolarians and foraminifera, the Mónosbél Group formed in Early to Late Bathonian time. The lower part of the complex is typified by a predominance of pelagic carbonates, shale and radiolarite with andesitic volcaniclastic intercalations. The higher part of the succession is characterized by polymictic olistostromes. Large olistoliths that are predominantly blocks of Bathonian shallow marine limestone (Bükkzsérc Limestone) appear in the upper part of the sequence. Based on the biostratigraphic and sedimentological data, results of analyses of the redeposited clasts and taking into consideration the concepts of the development of the western Neotethys domain, the evolutionary stages of the sedimentary basins were defined. The onset of the compressional stage led to initiation of nappe stacking that led to the formation of polymict olistostromes and then to the redeposition of large blocks derived from out-of-sequence nappes of the former platform foreland.

New geochronological data for the Haolibao porphyry Mo–Cu deposit, NE China, yield Permian crystallization zircon U–Pb ages of 278 ± 5 Ma for granite and 267 ± 10 Ma for the granite porphyry that hosts the Mo–Cu mineralization, and four Re–Os molybdenite ages yield an isochron age of 265 ± 3 Ma. These ages disagree with the previous K–Ar age determinations that suggest a correlation of intrusive rocks of the Haolibao area with the Yanshanian intrusive rocks of Cretaceous age. The mineralizations at the Haolibao area may be related to the tectonic–magmatic activity caused by collisional events between the North China Plate and Mongolian terranes during the Permian. The occurrence of the Haolibao plutonic rocks indicates that the Palaeo-Asian-Mongolian Ocean closed during the Permian along the Xilamulun River suture.

In NW Scotland, several alkaline intrusive complexes of Silurian age intrude the Caledonian orogenic front. The most northerly is the Loch Loyal Syenite Complex, which is divided into three separate intrusions (Ben Loyal, Beinn Stumanadh and Cnoc nan Cuilean). Mapping of the Cnoc nan Cuilean intrusion shows two main zones: a Mixed Syenite Zone (MZ) and a Massive Leucosyenite Zone (LZ), with a gradational contact. The MZ forms a lopolith, with multiple syenitic lithologies, including early basic melasyenites and later felsic leucosyenites. Leucosyenite melts mixed and mingled with melasyenites, resulting in extreme heterogeneity within the MZ. Continued felsic magmatism resulted in formation of the relatively homogeneous LZ, invading western parts of the MZ and now forming the topographically highest terrane. The identification of pegmatites, microgranitic veins and unusual biotite-magnetite veins demonstrates the intrusion's complex petrogenesis. Cross-sections have been used to create a novel 3D GoCad™ model contributing to our understanding of the intrusion. The Loch Loyal Syenite Complex is known to have relatively high concentrations of rare earth elements (REEs), and thus the area has potential economic and strategic value. At Cnoc nan Cuilean, abundant REE-bearing allanite is present within melasyenites of the MZ. Extensive hydrothermal alteration of melasyenites here formed steeply dipping biotite-magnetite veins, most enriched in allanite and other REE-bearing accessories. This study has thus identified the area of greatest importance for further study of REE enrichment processes in the Cnoc nan Cuilean intrusion.

The boundary between the Rhoscolyn and New Harbour formations on Holy Island, Anglesey, has been described as a high strain zone or as a thrust. The boundary is here described at four localities, with reference to the contrasting sedimentary and deformational character of the two formations. At one of these localities, Borth Wen, sandstones and conglomerates at the top of the Rhoscolyn Formation are followed, without any break, by tuffs and then mudstones of the New Harbour Formation. It is concluded that there is clear evidence of depositional continuity across the boundary here, and that both formations subsequently shared a common two-phase deformation. The first (D1) was manifestly different in intensity and scale in the two formations, whereas the second (D2) produced very similar structures in both. The other three localities provide continuity of sedimentary and tectonic features at this boundary in a traverse along the length of Holy Island, leading us to identify two previously unrecognized major D1 folds in addition to the Rhoscolyn Anticline. At one of these localities (Holyhead), we confirm the presence of Skolithos just below the boundary, supporting radiometric evidence for a lower Cambrian or later age for the Rhoscolyn Formation. A turbidite interpretation for both the Rhoscolyn and New Harbour formations best fits the available evidence. A deep-water depositional environment is still compatible with the sporadic presence of Skolithos burrows, but less so with reported observations of hummocky and swaley cross-stratification lower down the South Stack Group.

Early–Middle Miocene intraplate basalts from the Aleppo Plateau, NW Syria have been analysed for their platinum-group elements (PGEs). They contain extremely low PGE abundances, comparable with most alkali basalts, such as those from Hawaii, and mid-ocean ridge basalts. The low abundances, together with high Pd/Ir, Pt/Ir, Ni/Ir, Cu/Pd, Y/Pt and Cu/Zr are consistent with sulphide fractionation, which likely occurred during partial melting and melt extraction within the mantle. Some of the basalts are too depleted in PGEs to be explained solely by partial melting of a primitive mantle-like source. Such ultra-low PGE abundances, however, are possible if the source contains some mafic lithologies. Many of the basalts also exhibit suprachondritic Pd/Pt ratios of up to an order of magnitude higher than primitive mantle and chondrite, an increase too high to be attributable to fractionation of spinel and silicate minerals alone. The elevated Pd/Pt, associated with a decrease in Pt but not Ir and Ru, are also inconsistent with removal of Pt-bearing PGE minerals or alloys, which should have concurrently lowered Pt, Ir and Ru. In contrast, melting of a metasomatized source comprising sulphides whose Pt and to a lesser extent Rh were selectively mobilized through interaction with silicate melts, may provide an explanation.

The Liziyuan goldfield is located along the northern margin of the western part of the Qinling Orogen (WQO). The goldfield consists of five gold-only deposits hosted by metavolcanic rocks, and one polymetallic (Au–Ag–Pb) deposit hosted by the Tianzishan Monzogranite. As the Liziyuan goldfield appears to be spatially and temporally related to the Jiancaowan Porphyry, the study of the deposit provides a crucial insight into the relationship between tectonic-magmatic events and gold metallogenesis in the WQO. In this paper, we present whole-rock major and trace element geochemistry, and in situ zircon U–Pb and Lu–Hf isotopic data from the Tianzishan Monzogranite and Jiancaowan Porphyry. The two granitic plutons are enriched in LILEs and LREEs, depleted in HFSEs and have zircon εHf(t) values between −14.1 and −5.1 for the Tianzishan Monzogranite and between −21.0 and −8.4 for the Jiancaowan Porphyry. These characteristics indicate that the granites are derived from the crust. The Tianzishan Monzogranite has LA-ICP-MS zircon U–Pb ages of 256.1 ± 3.7 to 260.0 ± 2.1 Ma, which suggests that it was emplaced in the WQO during the convergence of the North and South (Yangtze) China cratons in the early stage of the Qinling Orogeny. In contrast, the porphyry has a LA-ICP-MS zircon U–Pb age of 229.2 ± 1.2 Ma, which is younger than the peak collision age, but corresponds to the widespread Late Triassic post-collisional granitic plutons in the WQO. The Tianzishan Monzogranite has somewhat higher Sr contents (196–631 ppm), lower Y (2.23–19.6 ppm) and Yb (0.20–2.01 ppm) contents, and a positive Eu/Eu* averaging 1.15. These characteristics suggest the pluton was derived from partial melting of the thickened crust. In contrast, the relatively higher MgO content (0.85–2.08 wt%) and Mg no. (43.4–58.2) of the Jiancaowan Porphyry indicates that insignificant amounts of subcontinental lithospheric mantle-derived mafic melts were involved in the generation of the magma. The Liziyuan goldfield is hosted by faults in greenschist-facies metamorphic rocks. Fluid inclusion studies suggest that gold was precipitated from CO2-rich, low-salinity and medium temperature fluids. This feature is consistent with the other orogenic gold deposits throughout the world. The field relationships and zircon U–Pb ages of the two granitic plutons suggest that gold mineralization is coeval with or slightly younger than the emplacement of the Jiancaowan Porphyry. Therefore, both the porphyry and deposit formed during the post-collisional stage of the Qinling Orogen.

Stratigraphic, structural, palaeocurrent and palaeomagnetic analyses of Upper Albian deep-water deposits in and around the Deba block (Northern Iberia) are presented. Results indicate an anticlockwise vertical-axis rotation of this block by 35° during a maximum time span of c. 1 Ma (Late Albian intra-C. auritus ammonite Subzone). This Albian syndepositional block rotation is interpreted to be the consequence of the coeval activity of conjugate major sinistral strike-slip faults and minor (antithetic) dextral strike-slip faults, which border the Deba block. On the base of conservative estimations, a minimum block-rotation rate of 35° Ma−1 and a sinistral strike-slip rate of 1.2 km Ma−1 are calculated. As a consequence of the interaction of the rotated Deba block with adjacent non-rotated blocks, its corners experienced coeval transpressive (NW and SE corners) and transtensional deformations (SW and, possibly, NE corners). At the transtensional SW corner, two domal high-reflective seismic structures have been recorded and interpreted as high-level magmatic laccoliths. These magmatic intrusions triggered the development of a mineralizing hydrothermal system, which vented to the Late Albian seafloor warm to hot hydrocarbon-rich fluids. Vented hydrocarbon was generated from Albian organic-rich sediments by contact alteration with hydrothermal fluids.

In this study, we show that the southern branch of the North Anatolian Fault has been active since Late Pliocene time and that evidence of activity is supported by geological and seismological data. The southern branch of the North Anatolian Fault consists of four segments from west to east: Yenice–Gönen, Manyas–Mustafakemalpaşa, Uluabat and Bursa. These faults delimit the Bursa–Gönen Depression, with the Bandırma–Mudanya Uplift to the north and Uludağ–Sularya Uplift to the south. The Bursa–Gönen Depression includes Upper Pliocene to Recent sediments that thicken to the south, suggesting a deposition pattern under active fault control. Study of fault kinematics suggests that the Bursa–Gönen Depression started as a small pull-apart basin during Late Pliocene time, and then evolved to a large depression. The faults delimiting this depression are still active and capable of producing future earthquakes.

The Xiaoxia anticline is a basement-cored fold in the northeastern Qinghai–Tibetan Plateau. It formed during the Middle–Late Cenozoic in a NNE-orientation oblique to prevailing WNW-striking thrusts in the surrounding region. The fold lies within the fault-bounded Xining Basin, which has behaved as a clockwise rotating and internally deforming block during the mid–late Tertiary. Proterozoic crystalline basement rocks and Jurassic–Cretaceous–Cenozoic terrestrial sediments exposed within the fold record three separate oblique-slip deformation events as determined by cross-cutting generations of faults and folds. The modern Xiaoxia anticline developed by: (1) outward-directed thrusting on the two fold limbs and, (2) oblique-slip thrusting on closely spaced minor NNE-striking faults that caused distributed uplift and passive shear folding of the sedimentary cover within the fold core. Tilted and thrusted river terraces on the flanks of the Xiaoxia anticline dated by optically stimulated luminescence and electron spin resonance indicate that folding has continued into the Late Quaternary (post-45.5 ± 5.5 ka) and therefore may still be active today. The development of the Xiaoxia anticline appears to be best explained in the context of the kinematic evolution of the Xining Basin's bounding strike-slip faults. Formation of the Xiaoxia anticline demonstrates that partitioned transpression in an evolving transpressional setting can invert intra-montane basins and produce basement-cored folds, thereby contributing to regional plateau uplift.

Detailed facies analysis and morphotectonic investigations of the Malin River's alluvial fan in the western Ganga Plain, India, reveal that the morphology of the fan is largely tectonically controlled whereas the sedimentary processes are mainly climatically controlled. The sedimentation occurred in two distinct evolutionary cycles which are separated by a time gap. The older cycle deposited thick gravelly units up to the distal-fan area, whereas the sediment fill of the younger cycle is gavel-dominated in the proximal-fan area, gravel–sand dominated in the middle-fan area and sand–mud dominated in the distal-fan area. The gravels of the older cycle were emplaced by intense sediment gravity flows during periods of strengthened monsoon and steeper regional gradient. During the younger cycle, the proximal to distal parts of the fan were dominated by different sedimentary processes. This was a time of relatively weaker monsoon and gentler regional slopes, when gravels could travel only up to the middle-fan area. The gravels in the proximal-fan area have mainly been deposited by sediment gravity flows and channel processes; in the middle-fan area channel processes, sheetfloods and sediment gravity flows have been the main sedimentary processes; and in the distal-fan area fluvial processes of channel migration and overbank deposition have been the main sedimentary processes.

The Kaj-Rostam Abad, Dashtak and Doab diapirs are part of the Precambrian–Cambrian Hormuz series that are rich in igneous inclusions concentrated by dissolution of diapiric salt. They are situated in the Iran–Pakistan salt range and commonly associated with inclusions of basalt, trachyte, andesite, micro-gabbro, gypsum and anhydrite, with lesser amounts of carbonate rocks. The mineral assemblage in these inclusions developed in three stages: (I) magmatic stage (diopside, Ti-augite, kaersutite, plagioclase, apatite, biotite and opaque minerals), (II) late magmatic stage (biotite, quartz, chlorite, albite, calcite, titanite, epidote, actinolite and opaque minerals) and (III) vein mineralization (quartz, chlorite, albite, calcite, garnet, epidote, opaque minerals and actinolite). Clinopyroxene is diopside to Ti-augite. Actinolite, kaersutite, albite and pycnochlorite are constituents of the metasomatic rocks of the area. Chlorite geothermometry yielded a temperature of 330–500 °C for chlorite formation. Clinopyroxene thermobarometry ranges from 960 ≤ T ≤ 1440 °C and 1 ≤ P ≤ 10 kbar. The presence of halite-bearing fluid inclusions in hydrothermal quartz veins with homogenization temperatures between 320 and 350 °C points to strong evidence of hydrothermal events. The salinity of these fluids is 39.8–42.7 wt% NaCl. δ18O data on hydrothermal quartz veins range from 14.89 to 22.09 ‰ (SMOW), indicating that the studied samples were affected by fluids originated from sedimentary-evaporitic rocks. Meteoric water that penetrated the evaporitic rocks likely mixed with late magmatic fluids while subjected to magmatic heat, when buried to depths of several kilometres by the Phanerozoic cover sequence. Whole-rock geochemistry data for the studied rocks emphasize their alkaline to sub-alkaline affinities, in a transitional magmatic series.