ALBERT

Description: The biostratigraphic significance of selected uppermost Famennian (Upper Devonian) and lower Tournaisian (Mississippian) brachiopod genera, belonging to the orders Rhynchonellida (e.g. Araratella ), Spiriferida (e.g. Sphenospira , Prospira ), Spiriferinida ( Syringothyris ) and Productida (except Chonetidina), is discussed. Owing to the difficulties of identifying productidine and strophalosiidine genera, in contrast to rhynchonellides and spiriferides, the biostratigraphic potential of the former has generally been overlooked. Brachiopods flourished in neritic environments that were unfavourable for conodonts and ammonoids. In the absence of the latter traditional marker fossils, they are potentially important for locating the Devonian–Carboniferous boundary in shallow water depositional settings in conjunction with rugose corals and foraminifers. On a worldwide scale, further work is required to reach a better assessment of the aftermath of the Hangenberg biological Crisis on brachiopods, notably in revising the faunas from the classical areas of the Famennian and Tournaisian stages in Western Europe.

Description: The selection of the global biomarker of the lower boundary of the Moscovian stages is one of the pressing issues of Carboniferous stratigraphy. Several solutions are suggested for this problem: Diplognathodus ellesmerensis Bender, Streptognathodus expansus (Igo & Koike) and Idiognathoides postsulcatus Nemirovskaya. The conodont species Declinognathodus donetzianus Nemirovskaya is one of the most prospective. It was detected in the rock sections of west Europe, the Donets Basin, the Moscow Syneclise, south Ural and the Appalachian Basin. The Volga region is also one of the places where Declinognathodus donetzianus Nemirovskaya is often met and this article is dedicated to detailed analysis of this species.

Description: Graptoloid evolutionary dynamics show a marked contrast from the Ordovician to the Silurian. Subdued extinction and origination rates during the Ordovician give way, during the late Katian, to rates that were highly volatile and of higher mean value through the Silurian, reflecting the significantly shorter lifespan of Silurian species. These patterns are revealed in high-resolution rate curves derived from the CONOP (constrained optimization) scaled and calibrated global composite sequence of 2094 graptoloid species. The end-Ordovician mass depletion was driven primarily by an elevated extinction rate which lasted for c . 1.2 Ma with two main spikes during the Hirnantian. The early Silurian recovery, although initiated by a peak in origination rate, was maintained by a complex interplay of origination and extinction rates, with both rates rising and falling sharply. The global 13 C curve echoes the graptoloid evolutionary rates pattern; the prominent and well-known positive isotope excursions during the Late Ordovician and Silurian lie on or close to times of sharp decline in graptoloid species richness, commonly associated with extinction rate spikes. The graptoloid and isotope data point to a relatively steady marine environment in the Ordovician with mainly background extinction rates, changing during the Katian to a more volatile climatic regime that prevailed through the Silurian, with several sharp extinction episodes triggered by environmental crises. The correlation of graptoloid species diversity with isotopic ratios was positive in the Ordovician and negative in the Silurian, suggesting different causal linkages. Throughout the history of the graptoloid clade all major depletions in species richness except for one were caused by elevated extinction rate rather than decreased origination rate.

Description: A multidisciplinary correlation of the Devonian–Carboniferous (D–C) boundary sections from the Moravian Karst (Czech Republic) and the Carnic Alps (Austria), based on conodont and foraminifer biostratigraphy, microfacies analysis, field gamma-ray spectroscopy (GRS), carbon isotopes and element geochemistry, is presented in this paper. The study is focused on the interval from the Middle Palmatolepis gracilis expansa Zone (Late Famennian) to the Siphonodella sandbergi Zone (Early Tournaisian). In Lesní lom (Moravian Karst), a positive 13 C excursion in the Bisphatodus costatus – Protognathodus kockeli Interregnum from a distinct laminated carbonate horizon is correlated with a carbon isotope excursion from the Grüne Schneid section of the Carnic Alps and is interpreted as the equivalent of the Hangenberg black shales and a local expression of the global Hangenberg Event sensu stricto . Higher up at both sections, a significant increase in the terrigenous input, which is inferred from the GRS signal and elevated concentrations of terrigenous elements (Si, Ti, Zr, Rb, Al, etc.), provides another correlation tieline and is interpreted as the equivalent of the Hangenberg sandstone. Both horizons are discussed in terms of relative sea-level fluctuations and palaeoceanographic changes. Recent studies show that conodont biostratigraphy is facing serious problems associated with the taxonomy of the first siphonodellids, their dependence on facies and discontinuous occurrences of protognathodids at the D–C boundary. Therefore, the correlative potential of geochemical and petrophysical signatures is high and offers an alternative for the refining of the problematic biostratigraphic division of the D–C boundary.

Description: Wiwaxia is an extinct early metazoan with uncertain affinities, which is well represented in strata of Cambrian Series 2–3 age. Well-preserved representatives of Wiwaxia are known from the Burgess Shale Biota and the Kaili Biota. Here, new material of Wiwaxia corrugata (Matthew, 1899) is reported from the upper part of the Tsinghsutung Formation (Cambrian Series 2) near Balang Village, Guizhou Province, China. These specimens have a close evolutionary relationship to Wiwaxia taijiangensis Zhao, Qian & Lee, 1994 from the overlying Kaili Formation. New Wiwaxia material from the Tsinghsutung Formation and observations of specimens with articulated individuals from the Kaili Formation suggest that Wiwaxia taijiangensis should be a junior synonym of W. corrugata . A new study indicates that W. corrugata has a wide geographic distribution, a short geological history and evolutionary uniqueness and provides new data on taphonomy of this genus.

Description: Trepostome bryozoan Dianulites borealis Astrova, 1965, the earliest known member of this genus, has been identified from the Early Ordovician of Severnaya Zemlya, Arctic Russia. This species developed hemispherical colonies which indicate that it lived on a relatively soft substrate with moderately low rates of sedimentation and erosion. The new record from Severnaya Zemlya expands the palaeogeographical distribution of Dianulites , known before from the Early Ordovician of Novaya Zemlya, Arctic Russia.

Description: New thermochronological data show that rapid Middle Miocene exhumation occurred synchronously along the Bitlis suture zone and in the southeastern Black Sea region, arguably as a far-field effect of the Arabia–Eurasia indentation. Collision-related strain focused preferentially along the rheological boundary between the multideformed continental lithosphere of northeastern Anatolia and the strong (quasi)oceanic lithosphere of the eastern Black Sea. Deformation in the southeastern Black Sea region ceased in late Middle Miocene time, when coherent westward motion of Anatolia and the corresponding activation of the North and East Anatolian Fault systems mechanically decoupled portions of the foreland from the Arabia–Eurasia collision zone.

Description: A preliminary summary of the lower Visean to uppermost Moscovian (Carboniferous) conodont succession and biostratigraphy of the Dianzishang section in Zhenning, Guizhou, South China is presented. Eleven conodont zones, in ascending order, can be recognized: Gnathodus praebilineatus , Gnathodus bilineatus , Lochriea ziegleri , Declinognathodus noduliferus , Neognathodus symmetricus , ‘ Streptognathodus ’ expansus (primitive form), ‘ Streptognathodus ’ expansus , Mesogondolella donbassica – Mesogondolella clarki , Idiognathodus podolskensis , Swadelina fauna and Idiognathodus swadei zones. The first occurrences of Lochriea ziegleri at the base of the Serpukhovian Stage, Declinognathodus noduliferus noduliferus at the base of the Bashkirian Stage and ‘ Streptognathodus ’ expansus at the base of the Moscovian Stage are recognized. The definitions of these stage boundaries, as well as that of the base of the Kasimovian Stage are discussed. Correlations with the Naqing section in South China, Russian and North American sections, as well as other important sections in the world, are considered.

Description: The Archaean Jiaodong Terrane is located in the southern segment of the Palaeoproterozoic Jiao-Liao-Ji Belt, which separates the Eastern Block of the North China Craton into the Longgang and Langrim blocks. Controversy has long surrounded the issue of whether the Jiaodong Terrane is part of the North China Craton or an exotic terrane. This study presents new zircon U–Pb ages for the major lithologies of the Jiaodong Terrane, and the results indicate that the terrane underwent two main magmatic events at ~2.89 Ga and 2.62–2.56 Ga and two metamorphic events at ~2.5 Ga and 1.9–1.8 Ga. These ages are consistent with those of other metamorphic complexes in the Eastern Block, suggesting that the Jiaodong Terrane was part of the Neoarchaean basement of the Eastern Block, which was reworked at 1.9–1.8 Ga in association with the development of the Palaeoproterozoic Jiao-Liao-Ji Belt.

Description: This study reports the conodont succession across the Visean–Serpukhovian (V/S) boundary interval at the Naqing section, South China. Continuous centimetre-scale sampling of the relatively deep-water section in recent years has provided new data for a more detailed biostratigraphy of conodonts across the Visean–Serpukhovian boundary. Three conodont zones were described in ascending order: the Gnathodus bilineatus , Lochriea nodosa and Lochriea ziegleri zones. The first appearance datum (FAD) of L. ziegleri has been moved down to 60.1 m above the base of the Naqing section. The correlation of the conodont succession across the Visean–Serpukhovian boundary in the Naqing section with other sections in Eurasia is discussed.

Description: The Tournaisian and Viséan were formerly considered as series and in Belgium were divided into two (Hastarian and Ivorian) and three stages (Moliniacian, Livian and Warnantian), which are now considered as substages. The Belgian substages are based on conodonts and foraminifers, and incidentally on rugose corals, and are described here. Their boundaries, biostratigraphy and sequence stratigraphy are well detailed and clearly defined. The base of the Hastarian (lower Tournaisian) corresponds to the base of the Tournaisian (base of Carboniferous); the base of the Ivorian (upper Tournaisian) corresponds to the appearance of the conodont Polygnathus communis carina , a little above the last Siphonodella ; the base of the Moliniacian (lower Viséan) corresponds to the base of the Viséan stage defined by the first occurrence of the foraminifer Eoparastaffella simplex ; the Livian (middle Viséan) corresponds to the foraminiferal MFZ12 Zone and is marked by the appearance of Koskinotextularia and Pojarkovella nibelis ; the base of the Warnantian (upper Viséan) is marked by the appearance of Neoarchaediscus , Vissariotaxis , Planospirodiscus , and Palaeotextularia with a bilaminar wall, the index taxa of the MFZ13- Neoarchaediscus Zone. The up-to-date chronostratigraphic subdivision of the Tournaisian and Viséan is not limited to Belgium and the surrounding areas. It can be applied through Eurasia as far as South China. The Belgian units could therefore be the basis for a future international division of the Tournaisian into two parts (Hastarian and Ivorian) and of the Viséan into three parts (Moliniacian, Livian and Warnantian), corresponding to time intervals of c. 5–8 Ma.

Description: The uninterrupted succession of the Mississippian–Pennsylvanian boundary beds in the Muradymovo section in the South Urals contains diverse fossils and has a high correlative potential. The Muradymovo section is located in the Zilair Megasynclinorium (ZM), which belongs to the West Uralian Subregion and displays carbonate-siliciclastic deep-water facies of the Bukharcha Formation, which is partly Serpukhovian (Kosogorian, Protvian and Yuldybaevian) and partly Bashkirian (Syuranian). In the southern ZM, the lower part of the formation contains argillaceous carbonates with beds of shale and siltstone, subordinate clastic limestones and limestone breccia, while the upper part is mostly limestone with cherty interbeds. In the north of the ZM, the formation mainly consists of limestone. The Muradymovo succession contains no identifiable gaps in the Mid-Carboniferous Boundary (MCB) portion and has a succession of foraminiferal, conodont, ammonoid and ostracod zones. The MCB in this section coincides with the base of the Bogdanovkian and is defined by the entry of Declinognathodus noduliferus. This level falls within the upper part of the foraminiferal Monotaxinoides transitorius Zone, is near the base of the ammonoid Homoceras–Hudsonoceras Genozone and can be correlated worldwide.

Description: The Task Group charged with proposing the GSSP for the base of the Serpukhovian Stage (Mississippian, Lower Carboniferous) is likely to use the global First Appearance Datum (FAD) of the conodont Lochriea ziegleri in the lineage Lochriea nodosa – L . ziegleri for the definition and correlation of the base of the stage. It is important to establish that the FAD of L . ziegleri in different basins is penecontemporaneous. Ammonoids provide high-resolution biostratigraphy in the Late Mississippian but their use in international correlation is limited by provincialism. However, it is possible to assess the levels of diachronism of the First Occurrence Datum (FOD) of L . ziegleri in sections in NW Europe using ammonoid zones. Published conodont distribution in the Rhenish Slate Mountains of Germany show the FOD of L . ziegleri in the Emstites novalis Biozone (upper part of the P 2c zone of the UK and Ireland) but L . ziegleri has also been reported as occurring in the Neoglyphioceras spirale Biozone (P 1d zone). In the Yoredale Group of northern England, the FOD of L . ziegleri is in either the P 1c or P 1d zone. In NW Ireland, the oldest records of both L . nodosa and L . ziegleri are from the Lusitanoceras granosum Biozone (P 2a ). Although there is some discrepancy in the recorded levels of the FOD of L . ziegleri in NW Europe, this may be as a result of collection failure. The base of the Serpukhovian based on the FAD of Lochriea ziegleri will be in the middle of the Brigantian regional Substage.

Description: A variety of host-fabric elements (HE) cut by cross-cutting elements (CE) in rocks defines flanking structures (FS) on mesoscopic and microscopic scales. There has been renewed interest in studying and classifying the FS for their morphologies, useful as shear sense indicators and geneses. Existing non-genetic morphologic parameters for the FS are reviewed, and two new classification schemes are presented. One of these is based on the nature of the CE and whether HE penetrates it. The other scheme takes account of all the potential combinations of drag/no drag and slip/no slip of the HE. Deciphering the shear sense of the rock body from FS is complicated because the angular relationship between the CE and the primary shear planes might be opposite to what is found between S- and C- ductile shear fabrics. Further, single CEs can curve and several similar FS occur in reverse forms. As with mineral fish, the shape asymmetries of microscopic CEs indicate the shear sense. Conjugate FS (with non-parallel CEs) with interfering perturbation fields around the CEs are more reliable shear-sense indicators than FS with single CE. During low but increasing bulk strains, FS may evolve from one type to another, e.g. from a- to s-type. At high strain, FS can resemble intrafolial or sheath fold. Whether the drag is normal or reverse depends fundamentally on the initial angle between the HE and the CE and the relative magnitudes of throw and vertical separation.

Description: Fifteen sandstone samples taken from pre-Cretaceous strata of the Yangtze Block are analysed to constrain the evolution of the South China Block, especially the assembly between the Yangtze and Cathaysia blocks. The results show that the maximum depositional age of the Neoproterozoic Lengjiaxi Group adjacent to the Cathaysia Block is c . 830 Ma, differing from that of the Kunyang and Dahongshan groups (〉 960 Ma) on the southwestern margin of the Yangtze Block. The detrital zircons from Palaeozoic samples from the Yangtze Block have similar age populations to those in the Cathaysia Block, and they may originate from the Cathaysia Block according to palaeogeographic, palaeocurrent and former research data. The detrital zircons of Middle–Upper Jurassic sandstones in the southwestern and central Yangtze Block yield dominant age populations at 2.0–1.7 Ga and subordinate groups of 2.6–2.4 Ga, 0.8–0.7 Ga and 0.6–0.4 Ga. The Upper Triassic strata may be derived from the southern Yangtze and North China blocks due to the collisions between the Indosina, South China and North China blocks, whereas the Jurassic sediments may be partly derived from uplift and erosion of the Jiangnan Orogen due to an intracontinental orogeny induced by Pacific subduction towards the Eurasia Plate. The detrital age spectra and provenance data for basement in the South China Block are analysed and compared with each other. The South China Block has affinity with Australia not only in the Columbia supercontinent but also in the Rodinia supercontinent. We infer the existence of an ancient orogen under the western Jiangnan Orogen, which may have occurred during the Columbia age, earlier than the Sibao orogeny. This is supported by seismic profile proof from the SinoProbe.

Description: New magnetic and seismic datasets offer a unique opportunity to document the geometry of the Appalachian front in a poorly studied segment of the orogen. Interpretation of high-resolution magnetic data allows, for the first time, the documentation of the contact between the autochthonous St Lawrence Platform and the Appalachians and highlights the regional significance of previously poorly documented ENE faults that experienced post-Ordovician strike-slip motion. Seismic data reveal tectonic slices in the foreland domain underlying the Appalachians and show that the depth of the décollement at the base of the Appalachian tectonic wedge varies significantly. Taken together, geological, magnetic and seismic data suggest that the geometry of the Appalachian front exhibits significant variations in map and cross-section views and recorded a polyphased structural history.

Description: The red-bed deposits in northern Iraq are situated in an active foreland basin adjacent to the Zagros Orogenic Belt, bound to the north by the Iranian plate thrust over the edge of the Arabian plate. The red-bed successions are composed of alternating red and brown silty mudstones, purplish red calcareous siltstone, fine- to coarse-grained pebbly sandstone and conglomerate. The red beds in the current study can be divided into four parts showing a trend of upward coarsening with fine-grained deposits at the top. A detailed petrographic study was carried out on the sandstone units. The clastic rocks consist mainly of calcite cemented litharenite with rock fragments (volcanic, metamorphic and sedimentary), quartz and minor feldspar. The petrographic components reflect the tectonic system in the source area, laterally ranging from a mixed orogenic and magmatic arc in Mawat–Chwarta area to recycled orogenic material rich in sedimentary rock fragments in the Qandel area. The Cretaceous–Palaeogene foreland basin of northern Iraq formed to the southwest of the Zagros Suture Zone and the Sanandaj–Sirjan Zone of western Iran. During Palaeogene time deposition of the red beds was caused by renewed shortening in the thrust sheets overlying the Arabian margin with uplift of radiolarites (Qulqula Formation), resulting in an influx of radiolarian debris in addition to continuing ophiolitic detritus. Mixed sources, including metamorphic, volcanic and sedimentary terranes, were present during deposition of the upper part of the red beds.

Description: The role of travertine fissure-ridges in reconstructing tectonics and related earthquakes is a challenging issue of recent debate directed at delineating historical/prehistorical seismic records. Indeed, direct measurements on a travertine fissure-ridge immediately after a seismic event have never been previously performed. We describe the co- and post-seismic effects of a M = 3.6 earthquake on fluid flow and travertine deposition in a geothermal area of Tuscany (Italy). Direct observation allows us to demonstrate that thermal spring (re)activation is directly influenced by transient seismic waves, therefore providing a basis for reconstructing seismic events in the past.

Description: At the southern boundary of the Rhodope Massif, NE Greece, the Kavala Shear Zone (KSZ) represents an example of the Eastern Mediterranean deep-seated extensional tectonic setting. During Miocene time, extensional deformation favoured syntectonic emplacement and subsequent exhumation of plutonic bodies. This paper deals with the strain-related changes in macroscopic, geochemical and microstructural properties of the lithotypes collected along the KSZ, comprising granitoids from the pluton, aplitic dykes and host rock gneisses. Moreover, we investigated the evolution of seismic anisotropy on a suite of granitoid mylonites as a result of progressive strain. Isotropic compressional and shear wave velocities ( V p , V s ) and densities calculated from modal proportions and single-crystal elastic properties at given pressure–temperature ( P – T ) conditions are compared to respective experimental data including the directional dependence (anisotropy) of wave velocities. Compared to the calculated isotropic velocities, which are similar for all of the investigated mylonites (average values: V p ~ 5.87 km s –1 , V s ~ 3.4 km s –1 , V p / V s = 1.73 and density = 2.65 g cm –3 ), the seismic measurements give evidence for marked P-wave velocity anisotropy up to 6.92% (at 400 MPa) in the most deformed rock due to marked microstructural changes with progressive strain, as highlighted by the alignment of mica, chlorite minerals and quartz ribbons. The highest P- and S-wave velocities are parallel to the foliation plane and lowest normal to the foliation plane. Importantly, V p remains constant within the foliation with progressive strain, but decreases normal to foliation. The potential of the observed seismic anisotropy of the KSZ mylonites with respect to detectable seismic reflections is briefly discussed.

Description: New petrological and U–Pb zircon geochronological information has been obtained from intrusive plutonic rocks and migmatites from the Cap de Creus massif (Eastern Pyrenees) in order to constrain the timing of the thermal and tectonic evolution of this northeasternmost segment of Iberia during late Palaeozoic time. Zircons from a deformed syntectonic quartz diorite from the northern Cap de Creus Tudela migmatitic complex yield a mean age of 298.8±3.8 Ma. A syntectonic granodiorite from the Roses pluton in the southern area of lowest metamorphic grade of the massif has been dated at 290.8±2.9 Ma. All the analysed zircons from two samples of migmatitic rocks yield inherited ages from the Precambrian metasedimentary protolith (with two main age clusters at c . 730–542 Ma and c . 2.9–2.2 Ga). However, field structural relationships indicate that migmatization occurred synchronously with the emplacement of the quartz dioritic magmas at c . 299 Ma. Thus, the results of this study suggest that subduction-related calc-alkaline magmatic activity in the Cap de Creus was coeval and coupled with D 2 dextral transpression involving NNW–SSE crustal shortening during Late Carboniferous – Early Permian time ( c . 299–291 Ma). Since these age determinations are within the range of those obtained for undeformed (or slightly deformed) calc-alkaline igneous rocks from NE Iberia, it follows that the Cap de Creus massif would represent a zone of intense localization of D 2 transpression and subsequent D 3 ductile wrenching that extended into the Lower Permian during a transitional stage between the Variscan and Cimmerian cycles.

Description: During Early, as proposed by the International commission on stratigraphy Pleistocene times, interacting fluvial and aeolian processes constructed wide alluvial plains over an evaporite-dominated Miocene substratum in the central Ebro Basin. An exceptional site where these deposits show faults, folds, diapirs, karst structures and unconformities has been studied in detail. Analysis of particular structures demonstrates the interaction by that time of tectonic faulting, diapirism, karstification and sedimentation in an area where deformation was traditionally linked to the presence of underlying evaporites, without proposing any precise mechanism. Multiple approaches (sedimentology, structural geology and geophysics) have been used in order to discriminate the origin of each type of structure as well as to understand the interaction between different processes. Numerous normal faults and fractures of variable size are consistent with the regional stress field. Pleistocene deposits are pierced by diapirs of Miocene evaporites and disrupted by karst structures with different geometries (tubular, funnel and vault), both partially controlled by tectonics. The example described is proposed as an analogue model that could successfully illustrate evolution patterns of basins of potential interest for petroleum geology where similar processes have actuated, resulting in complex stratigraphical architectures.

Description: Gold-bearing mineral deposits occur over a strike distance of 〉300 km within the Grampian Terrane of Scotland and Ireland. This terrane consists of Neoproterozoic–Lower Ordovician rocks of the Dalradian Supergroup that were polyphase deformed and metamorphosed during the c . 470 Ma Grampian Orogeny. Sulphide-rich Au–Ag deposits occur in Scotland at Calliachar–Urlar Burn, Tombuie, Tyndrum and Cononish, and in Ireland at Curraghinalt (Omagh), Cavanacaw, Croagh Patrick, Cregganbaun and Bohaun. They are hosted by 0.1–6 m thick quartz veins and have a similar overall mineralogy, including native gold, As, Cu, Fe, Pb and Sn sulphides, with hessite, tetrahedrite and electrum present in the first six localities above. The mineralized quartz veins, which are characterized by open-space textures, crystallized at c . 3–5 km depth in the crust. All of the deposits were structurally controlled and, apart from Curraghinalt, occur within second-order Riedel R, R' and T fractures resulting from a regional N–S-trending maximum principal stress. These deposits are of Upper Silurian to Lower Devonian (post-Scandian) age, and are inferred to have crystallized from hot, silica-rich metamorphic fluids derived from dehydration reactions at the greenschist/amphibolite-facies boundary. Curraghinalt is an older, Grampian, thrust-related deposit. Plutonic igneous rocks (mainly granitoid) contributed in part to the fluids, which were channelled into major orogen-parallel, strike-slip faults, to be injected by fault-valve pumping into the damage zones and fault breccias of newly formed Riedel fractures. Any residual fluid probably percolated to the ground surface to form Rhynie chert-type hot-springs.

Description: This study reports on a ~ 150 m thick macrofossil-barren sequence of siliciclastic sediments from a Burdigalian age (Early Miocene) freshwater lake. The lake was located within an incipient rift system of the Most Basin in the Ohře (Eger) Graben, which was part of the European Cenozoic Rift System, and had an original area of 1000 km 2 . Sediments from the HK591 core that cover the entire thickness of the lake deposits and some of the adjacent stratigraphic units were analysed by X-ray fluorescence spectroscopy (a proxy for element composition) and magnetic polarity measurement. The element proxies were subjected to frequency analysis, which provided estimated sedimentation rates, and allowed for sediment dating by magnetostratigraphy and orbital tuning of the age model. Based on the resulting age model and the known biostratigraphy, the lake was present between 17.4 and 16.6 Ma, which includes the onset of the Miocene Climatic Optimum in the latest Early Miocene. The identification of orbital forcing (precession, obliquity and short eccentricity cycles) confirms the stability of the sedimentary environment of the perennial lake in an underfilled basin. The dating allowed the sediment record to be interpreted in the context of the current knowledge of the European climate during that period. The stability of the sedimentary environment confirms that precipitation was relatively stable over the period recorded by the sediments.

Description: Spectacular celestine geodes occur in a Jurassic peri-evaporitic sequence (Ardon Formation) exposed in Makhtesh Ramon, southern Israel. The geodes are found only in one specific location: adjacent to an intrusive contact with a Lower Cretaceous basaltic dyke. Celestine, well known in sedimentary associations worldwide and considered as a low temperature mineral, may therefore be associated with magmatic-induced hydrothermal activity. Abundant fluid inclusions in celestine provide valuable information on its origin: gas-rich inclusions in celestine interiors homogenized at T≥200°C whereas smaller liquid-rich inclusions record the growth of celestine rims at T≤200°C. Near 0°C melting temperatures of some fluid inclusions and the occurrence of hydrous Ca-sulphate solid crystals in other inclusions indicate that celestine precipitated from variably concentrated Ca-sulphate aqueous solutions of meteoric origin. Celestine crystallized from meteoric water heated by the cooling basaltic dyke at shallow levels ( c. 160 m) during a Lower Cretaceous thermal perturbation recorded by regional uplift and magmatism. The 87 Sr/ 86 Sr ratio of geode celestine, 0.7074, is similar to that measured in the dolostones of the host Jurassic sequence, but differs markedly from the non-radiogenic ratio of the dyke. Strontium in celestine was derived from dolostones preserving the 87 Sr/ 86 Sr of Lower Jurassic seawater, while sulphur ( 34 S = 19.9) was provided by in situ dissolution of precursor marine gypsum ( 34 S = 16.8) indicated by relict anhydrite inclusions in celestine. Low-temperature meteoric fluid flow during the Campanian caused alteration of the dyke into secondary clays and alteration of geodal celestine into quartz, calcite and iron oxides.

Description: The Phanerozoic subduction system of the Korean peninsula is considered to have been activated by at least Middle Permian time. The geochemically arc-like Andong ultramafic complex (AUC) occurring along the border between the Precambrian Yeongnam massif and the Cretaceous Gyeongsang back-arc basin provides a rare opportunity for direct study of the pre-Cretaceous mantle wedge lying above the subduction zone. The tightly constrained SHRIMP U–Pb age of zircons extracted from orthopyroxenite specimens (222.1±1.0 Ma) is indistinguishable from the Ar/Ar age of coexisting phlogopite (220±6 Ma). These ages represent the timing of suprasubduction zone magmatism likely in response to the sinking of cold and dense oceanic lithosphere and the resultant extensional strain regime in a nascent arc environment. The nearly coeval occurrence of a syenite-gabbro-monzonite suite in the SW Yeongnam massif also suggests an extensional tectonic setting along the continental margin side during Late Triassic time. The relatively enriched Hf range of dated zircons (+6.2 to –0.6 at 222 Ma) is in contrast to previously reported primitive Sr–Nd–Hf isotopic features of Cenozoic mantle xenoliths from Korea and eastern China. This enrichment is not ascribed to contamination by the hypothetical Palaeozoic crust beneath SE Korea, but is instead attributable to metasomatism of the lithospheric mantle during the earlier subduction of the palaeo-Pacific plate. Most AUC zircons show a restricted core-to-rim spread of Hf values, but some grains testify to the operation of open-system processes during magmatic differentiation.

Description: Lower Cretaceous pedogenic carbonates exposed in SE China have been dated by U–Pb isotope measurements on single zircons taken from intercalated volcanic rocks, and the ages integrated with existing stratigraphy. 13 C values of calcretes range from –7.0 to –3.0 and can be grouped into five episodes of increasing–decreasing values. The carbon isotope proxy derived from these palaeosol carbonates suggests p CO 2 mostly in the range 1000–2000 parts per million by volume (ppmV) at S ( z ) (CO 2 contributed by soil respiration) = 2500 ppmV and 25°C during the Hauterivian–Albian interval ( c . 30 Ma duration). Such atmospheric CO 2 levels are 4–8 times pre-industrial values, almost double those estimated by geochemical modelling and much higher than those established from stomatal indices in fossil plants. Rapid rises in p CO 2 are identified for early Hauterivian, middle Barremian, late Aptian, early Albian and middle Albian time, and rapid falls for intervening periods. These episodic cyclic changes in p CO 2 are not attributed to local tectonism and volcanism but rather to global changes. The relationship between reconstructed p CO 2 and the development of large igneous provinces (LIPs) remains unclear, although large-scale extrusion of basalt may well be responsible for relatively high atmospheric levels of this greenhouse gas. Suggested levels of relatively low p CO 2 correspond in timing to intervals of regional to global enrichment of marine carbon in sediments and negative carbon isotope ( 13 C) excursions characteristic of the oceanic anoxic events OAE1a (Selli Event), Kilian and Paquier events (constituting part of the OAE 1b cluster) and OAE1d. Short-term episodes of high p CO 2 coincide with negligible carbon isotope excursions associated with the Faraoni Event and the Jacob Event. Given that episodes of regional organic carbon burial would draw down CO 2 and negative 13 C excursions indicate the addition of isotopically light carbon to the ocean–atmosphere system, controls on the carbon cycle in controlling p CO 2 during Early Cretaceous time were clearly complex and made more so by atmospheric composition also being affected by changes in silicate weathering intensity.

Description: The absence of a sedimentary record on large cratonic areas often prevents the reconstruction of the history of their vertical movements. The Reguibat Rise, belonging to the West African Craton, is typically a large basement high, whose Meso-Cenozoic history is poorly known because of the extreme reduction of this sedimentary record. In this paper we present the first thermochronological data from the centre of the Reguibat Rise, and combine them with the geometry of the sedimentary formations in the adjoining Tindouf and Taoudeni basins situated north and south, respectively. Fission track analysis on apatite yields ages from 256±21 Ma to 139±8 Ma, and 120±10 Ma by (U–Th)/He dating. Two competing scenarios are tested based on these data with thermal history modelling. We favour the scenario that includes a Late Jurassic/Early Cretaceous cooling of the samples, based on stratigraphical constraints and the thermochronological results. We then propose a new model for the evolution of this region and reveal the occurrence of a previously unknown major exhumation event at the Jurassic/Cretaceous transition accounting for the main present-day structures.

Description: Cretaceous granites are widespread in the North Dabie orogen, Central China, but their emplacement sequence and mechanism are poorly known. The Tiantangzhai Complex in the North Dabie Complex is the largest Cretaceous granitic suite consisting of six individual intrusions. In this study, zircon U–Pb ages are used to constrain the crystallization and protolith ages of these intrusions. The Shigujian granite is a syn-tectonic intrusion with an age of 141 Ma. This granite was emplaced under a compressional regime. Oscillatory rims of zircons have yielded two peaks at 137±1 Ma and 125±1 Ma. The 137±1 Ma peak represents the beginning of orogenic extension and tectonic collapse, whereas the 125±1 Ma peak represents widespread granitic magmatism. Zircon cores have yielded concordant ages between 812 and 804 Ma, which indicate a crystallization age for the protolith. The Tiantangzhai granites show relatively high Sr contents and high La/Yb and Sr/Y ratios. The Shigujian granite has positive Eu anomalies resulting from partial melting of a plagioclase-rich source in an over-thickened crust. Correspondingly, in situ Lu–Hf analyses from zircons yield high negative Hf ( t ) values from –24.8 to –26.6, with two-stage Hf model ages from 2748±34 to 2864±40 Ma, suggesting that the magmas were dominantly derived from partial melting of middle to lower crustal rocks. The Dabie orogen underwent pervasive NW–SE extension at the beginning of the early Cretaceous associated with subduction of the Palaeo-Pacific plate beneath eastern China.

Description: The Rogart igneous complex is unique within the northern Scottish Caledonides because it comprises an apparent continuum of magma types that records a progressive change in emplacement mechanisms related to large-scale tectonic controls. Syn-D 2 leucogranites and late-D 2 quartz monzodiorites were emplaced during crustal thickening and focused within the broad zone of ductile deformation associated with the Naver Thrust. In contrast, emplacement of the post-D 2 composite central pluton was controlled by development of a steeply dipping dextral shear zone along the Loch Shin Line, interpreted as an anti-Riedel shear within the Great Glen Fault system. The mantle-derived nature of the late-to-post-D 2 melts implies that the Naver Thrust and the Loch Shin Line were both crustal-scale structures along which magmas were channelled during deformation. A U–Pb zircon age of 425±1.5 Ma for the outer component of the central pluton provides an upper limit on regional deformation and metamorphism within host Moine rocks. These findings are consistent with the view that a fundamental change in tectonic regime occurred in the Scottish Caledonides at c. 425 Ma, corresponding to the switch from regional thrusting that resulted from the collision of Baltica and Laurentia, to the development of the orogen-parallel Great Glen Fault system.

Description: 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 K 1 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.

Description: U–Pb and Lu–Hf isotope analyses of detrital zircon from the latest Ordovician (Hirnantian) Langøyene Formation, the Late Silurian Ringerike Group and the Late Carboniferous Asker Group in the Oslo Rift were obtained by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Overall the U–Pb dating yielded ages within the range 2861–313 Ma. The U–Pb age and Lu–Hf isotopic signatures correspond to virtually all known events of crustal evolution in Fennoscandia, as well as synorogenic intrusions from the Norwegian Caledonides. Such temporally and geographically diverse source areas likely reflect multiple episodes of sediment recycling in Fennoscandia, and highlights the intrinsic problem of using zircon as a tracer-mineral in ‘source to sink’ sedimentary provenance studies. In addition to its mostly Fennoscandia-derived detritus, the Asker Group also have zircon grains of Late Devonian – Late Carboniferous age. Since no rocks of these ages are known in Fennoscandia, these zircons are inferred to be derived from the Variscan Orogen of central Europe.

Description: The sandstone composition analysis carried out on the samples from three different sections (western section, middle section and eastern section) of the Upper Jurassic Emuerhe Formation in the Mohe Basin, northeastern China, reveals that the Okhotsk orogenic belt and the Ergun massif basement are the source areas for the Emuerhe Formation. The source area of the western section and the A segment of the middle section is the Okhotsk orogenic belt. The tectonic attributes of the Okhotsk orogenic belt are those of a dissected arc. The transportation distance of clastic rocks from these sections gradually lengthened, and the uplift rate of the Okhotsk orogenic belt gradually increased. The source area of the eastern section and the B segment of the middle section is the Ergun massif basement. Compared with the Okhotsk orogenic belt, the tectonic attributes and uplift rate of the Ergun massif basement are different from the former. The attributes of the Ergun massif basement are those of basement uplift. The transportation distance of clastic rocks from the eastern section and the B segment of the middle section gradually shortened, and the uplift rate of the Ergun massif basement gradually decreased. These conclusions are consistent with the characteristics of a foreland basin. Thus, we can draw the conclusion that the Mohe Basin belongs to the foreland basin.

Description: In Timpoweap Canyon near Hurricane (Utah, USA), spectacular outcrop conditions of Early Triassic rocks document the geometric relationships between a massive Smithian fenestral-microbial unit and underlying, lateral and overlying sedimentary units. This allows us to reconstruct the evolution of depositional environments and high-frequency relative sea-level fluctuations in the studied area. Depositional environments evolved from a coastal plain with continental deposits to peritidal settings with fenestral-microbial limestones, which are overlain by intertidal to shallow subtidal marine bioclastic limestones. This transgressive trend of a large-scale depositional sequence marks a long-term sea-level rise that is identified worldwide after the Permian–Triassic boundary. The fenestral-microbial sediments were deposited at the transition between continental settings (with terrigenous deposits) and shallow subtidal marine environments (with bioturbated and bioclastic limestones). Such a lateral zonation questions the interpretation of microbial deposits as anachronistic and disaster facies in the western USA basin. The depositional setting may have triggered the distribution of microbial deposits and contemporaneous marine biota. The fenestral-microbial unit is truncated by an erosional surface reflecting a drop in relative sea level at the scale of a medium depositional sequence. The local inherited topography allowed the recording of small-scale sequences characterized by clinoforms and short-distance lateral facies changes. Stratal stacking pattern and surface geometries allow the reconstruction of relative sea-level fluctuations and tracking of shoreline migrations. The stacking pattern of these small-scale sequences and the amplitude of corresponding high-frequency sea-level fluctuations are consistent with climatic control. Large- and medium-scale sequences suggest a regional tectonic control.

Description: We present detailed biostratigraphy based on conodonts and palaeoenvironmental trends deduced from microfacies and conodont abundance through the Famennian (Late Devonian) at Col des Tribes (Montagne Noire, France). The succession is characterized by micritic limestones deposited in settings oscillating between mid to outer ramp. Facies contain poor fauna, widely dominated by nektonic organisms. This section is complete and one of the most conodont-rich for the Famennian of the north Gondwana-related area. The Upper Kellwasser event (Frasnian–Famennian boundary) and the Hangenberg (Devonian–Carboniferous boundary) have been lithologically identified. They are characterized by decimetre-thick black dysoxic to anoxic argillaceous sediments. The Condroz and annulata events, although not materialized by lithological changes, have been positioned due to the precise stratigraphy. The first event occurred during the deposition of condensed ferruginous facies (griotte limestones) and the second event during the deposition of micrites barren of benthic fauna. The combination of information from both facies and conodont biofacies changes allows a general sea-level curve through the entire Famennian for north Gondwana to be proposed for the first time. At Col des Tribes, the general trend is a slight deepening upwards from triangularis to trachytera zones, then a pronounced shallowing-upwards trend from upper trachytera to praesulcata zones. This curve correlates with the well-known reference curve from Euramerica concerning the late Famennian ( trachytera to praesulcata Zones). There are some discrepancies in minor cycles which can be explained by tectonical phenomena at the onset of the edification of the Variscan belt in Europe.

Description: Sinaspideretes wimani Young & Chow, 1953 was based on a single shell from the Jurassic red beds of the Sichuan Basin. Originally referred to Trionychidae but later tentatively assigned to Carettochelyidae, it was long thought to be the oldest representative of those families. The re-examination of the carapace and further preparation of the plastron of the holotype of S. wimani revealed a number of important characters which clearly exclude this taxon from both Trionychidae and Carettochelyidae, but unite it with the primitive trionychoid Yehguia tatsuensis (Ye, 1963). S. wimani is therefore considered as the basalmost member of Trionychoidae. Our study adds to the evidence from the fossil record for the antiquity of Trionychoidae, thus is in agreement with the early split of Trionychia (Trionychidae and Carettochelyidae) among the crown Testudines suggested by the molecular phylogeny of turtles.

Description: The geochemical and isotopic characteristics of metamorphosed Svecofennian mafic dykes from the Dannemora area in the NE part of the Bergslagen region in central Sweden were investigated and compared to mafic intrusive rocks in their vicinity. The dykes, with an inferred age of c . 1860–1870 Ma, are calc-alkaline, sub-alkaline and basaltic in composition and have a mixed subduction and within-plate geochemical affinity. They are the result of mixing of at least three mantle source components with similar basaltic major element composition, but different concentrations of incompatible trace elements. Magma M1 is strongly enriched both in Rare Earth Elements (REE) and High-Field-Strength Elements (HFSE); magma M2 is highly enriched in Large-Ion Lithophile Elements (LILE, except Sr) with only moderate enrichment in HFSE and REE (particularly low in Heavy Rare Earth Elements); and magma M3 is enriched in Sr and has a flat REE profile. Magma M3 also has a somewhat more positive (depleted) initial Nd value of +1.8, compared to +0.4 to +0.5 for magmas M1 and M2. The magma evolution was controlled by a mixture of fractionation (mainly affecting the compatible elements) and mixing, best seen in the incompatible element concentrations and the Nd isotope data. The basaltic overall composition indicates little or no wholesale contamination by upper continental crust, but the dykes have undergone later metasomatic changes mainly affecting the alkali elements.

Description: We focus on an active continental margin related to northwards subduction during the Eocene in which sedimentary melange (‘olistostromes’) forms a key component. Maastrichtian – Early Eocene deep-marine carbonates and volcanic rocks pass gradationally upwards into a thick succession (〈800 m) of gravity deposits, exposed in several thrust sheets. The lowest levels are mainly siliciclastic turbidites and debris-flow deposits. Interbedded marls contain Middle Eocene planktonic/benthic foraminifera and calcareous nannofossils. Sandstones include abundant ophiolite-derived grains. The higher levels are chaotic debris-flow deposits that include exotic blocks of Late Palaeozoic – Mesozoic neritic limestone and dismembered ophiolite-related rocks. A thinner sequence (〈200 m) in one area contains abundant redeposited Paleogene pelagic limestone and basalt. Chemical analysis of basaltic clasts shows that some are subduction influenced. Basaltic clasts from unconformably overlying alluvial conglomerates (Late Eocene – Oligocene) indicate derivation from a supra-subduction zone ophiolite, including boninites. Taking account of regional comparisons, the sedimentary melange is interpreted to have formed within a flexurally controlled foredeep, floored by continental crust. Gravity flows including large limestone blocks, multiple debris flows and turbidites were emplaced, followed by southwards thrust imbrication. The emplacement was possibly triggered by the final closure of an oceanic basin to the north (Alanya Ocean). Further convergence between the African and Eurasian plates was accommodated by northwards subduction beneath the Kyrenia active continental margin. Subduction zone rollback may have triggered collapse of the active continental margin. Non-marine to shallow-marine alluvial fans prograded southwards during Late Eocene – Oligocene time, marking the base of a renewed depositional cycle that lasted until latest Miocene time.

Description: The ancient marine limestone beds of the upper part of the Guanling Formation, Panxian County, Guizhou Province, SW China, yielded a wide range of high-diversity well-preserved marine reptiles such as the fully aquatic protorosaur with an extremely long neck Dinocephalosaurus orientalis , the oldest mixosaurid ichthyosaurs and lariosaurs. However, there is no precise isotopic age to study the intriguing origin, evolution and emigration history of the important fauna. We report a sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon age for a volcanic tuff bed within the upper part of the Guanling Formation. The result indicates that the age of the fossil horizon is 244.0±1.3 Ma, 14 Ma earlier than the previously estimated age based on conodont evidence. We consider that the marine reptiles had a relatively rapid evolution during Middle Triassic time, some 8 Ma after the end-Permian mass extinction.

Description: The discovery of c . 1.77 Ga A-type granite in the Tarim Craton (TC) provides the first evidence that supports an extensional event related to fragmentation of the Columbia supercontinent in the late Palaeoproterozoic. We present laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb ages, Lu–Hf isotopic data and the whole-rock geochemical and Nd isotopic data of A-type granites in the Dunhuang area in the SE Tarim Craton. Zircon U–Pb dating for three granite samples indicate that they were emplaced at c . 1.77 Ga. Zircons from these granites have Hf ( t ) values ranging from –5.9 to 8.7, corresponding to two-stage model ages of 1.9–2.7 Ga. These granites exhibit the following petrological geochemical characteristics that are typical of A-type granite: (a) high content of SiO 2 and alkalis (i.e. high K 2 O + Na 2 O with K 2 O/Na 2 O 〉 1), enrichment of high-field-strength elements (HFSE) and rare Earth elements (REE) (except for Eu) and extreme depletion of Ba, Sr, P, Ti and Eu; (b) 10000 x Ga/Al ratios in the Dunhuang granites of 3.5–4.4, with an average value of 3.79 which is similar to the global average of 3.75 for A-type granites; (c) the presence of characteristic minerals such as amphibole, sphene and perthite; and (d) zirconium saturation temperature results indicate that the Dunhuang granites have high initial magmatic temperatures in the range 887–950°C, similar to those of typical of A-type granites. Whole-rock Nd ( t ) values range from –2.5 to –6.2 and T DM model ages from 2.3 to 2.7 Ga. Nd–Hf isotopic and whole-rock geochemical data indicate that these granites were most likely derived from the late Archean crustal source in a post-collisional/post-orogenic extensional tectonic environment. The late Palaeoproterozoic A-type granites in the TC could be correlated with those of the North China Craton (NCC), India and the Canadian Shield, thus demonstrating extensional tectonics and break-up of the Columbia supercontinent.

Description: Ion microprobe dating in Wedel Jarlsberg Land, southwestern Spitsbergen, provides new evidence of early Neoproterozoic ( c . 950 Ma) meta-igneous rocks, the Berzeliuseggene Igneous Suite, and late Neoproterozoic ( c . 640 Ma) amphibolite-facies metamorphism. The older ages are similar to those obtained previously in northwestern Spitsbergen and Nordaustlandet where they are related to the Tonian age Nordaustlandet Orogeny. The younger ages complement those obtained recently from elsewhere in Wedel Jarlsberg Land of Torellian deformation and metamorphism at 640 Ma. The Berzeliuseggene Igneous Suite occurs in gently N-dipping, top-to-the-S-directed thrust sheets on the eastern and western sides of Antoniabreen where it is tectonically intercalated with younger Neoproterozoic sedimentary formations, suggesting that it provided a lower Tonian basement on which upper Tonian to Cryogenian sediments (Deilegga Group) were deposited. They were deformed together during the Torellian Orogeny, prior to deposition of Ediacaran successions (Sofiebogen Group) and overlying Cambro-Ordovician shelf carbonates, and subsequent Caledonian and Cenozoic deformation. The regional importance of the late Neoproterozoic Torellian Orogeny in Svalbard's Southwestern Province and its correlation in time with the Timanian Orogeny in the northern Urals as well as tectonostratigraphic similarities between the Timanides and Pearya (northwestern Ellesmere Island) favour connection of these terranes prior to the opening of the Iapetus Ocean and Caledonian Orogeny.

Description: Here we record the occurrence of a new species of the Herefordshire Lagerstätte ostracod genus Pauline from the Lower Silurian (upper Telychian) of North Greenland. Pauline nivisis sp. nov. was recovered from a limestone boulder (Pentamerus Bjerge Formation) collected south of Kap Schuchert, Washington Land. It is reasonable to transpose the palaeobiology known from the Herefordshire Pauline avibella – body, limbs including swimming antennae, lateral eyes, gills and alimentary system – into the carapace of the Greenland species, which represents the oldest cylindroleberidid myodocopid and almost the oldest known myodocope, and is the first record of a Herefordshire Lagerstätte genus from outside the Welsh Borderland locality. Morphological, sedimentological and faunal evidence suggest that the Greenland species was nektobenthic. This is compatible with the notion that ostracods (specifically myodocopids) did not invade the water column until later in the Silurian, in the Wenlock and Ludlow epochs. Pauline is an Early Silurian link between ‘Baltic-British’ and North Laurentian ostracod faunas, endorsing the idea that the UK and Greenland were in close geographical proximity, near a remnant Iapetus Ocean, during late Llandovery time.

Description: The final stages of the Variscan orogeny in Central Europe were associated with voluminous granitic plutonism and widespread volcanism. Four samples representative of the main rhyolitic volcanic units from the Stephanian–Permian continental succession of the North-Sudetic Basin, in the eastern part of the Variscan Belt, were dated using the SIMS (SHRIMP) zircon method. Three samples show overlapping 206 Pb– 238 U mean ages of 294 ± 3, 293 ± 2 and 292 ± 2 Ma, and constrain the age of the rhyolitic volcanism in the North-Sudetic Basin at 294–292 Ma. This age corresponds to the Early Permian – Sakmarian Stage and is consistent with the stratigraphic position of the lava units. The fourth sample dated at 288 ± 4 Ma reflects a minor, younger stage of (sub)volcanic activity in the Artinskian. The silicic activity was shortly followed by mafic volcanism. The rhyolite samples contained very few inherited zircons, possibly owing to limited contribution of crustal sources to the silicic magma, or owing to processes involved in anatectic melting and magma differentiation (e.g. resorption of old zircon by Zr-undersaturated melts). The SHRIMP results and the stratigraphic evidence suggest that the bimodal volcanism terminated the early, short-lived (10–15 Ma) and vigorous stage of basin evolution. The Permian volcanism in the North-Sudetic Basin may be correlated with relatively late phases of the regional climax of Late Palaeozoic volcanism in Central Europe, constrained by 41 published SHRIMP zircon age determinations at 299–291 Ma. The Permian volcanism and coeval plutonism in the NE part of the Bohemian Massif can be linked to late Variscan, post-collisional extension.

Description: A microbioherm-bearing hardground within the middle Silurian (Wenlock) Massie Formation near Napoleon, southeastern Indiana, United States is encrusted by the attachment structures of numerous pelmatozoan echinoderms. Among the most common of these holdfasts are multi-plated discoidal structures representing the thecal attachments of diploporite ‘cystoids’. This large population of holdfasts permits the first detailed taphonomic and palaeoecologic study of hardground diploporite attachments, allowing for increased morphological understanding of these rarely studied structures and facilitating identification of holdfasts in deposits where they might have been overlooked or misidentified. The biostratinomic sequence commences with detachment of thecae, followed by weathering of isolated discoidal holdfasts to bring out radiating canal structures and plate sutures, eventually leading to removal of the interior floor to expose the underlying substrate. Continued exposure can result in separation of component holdfast plates, though cementation to the substrate prevents scattering of plates. Diagenetic precipitation of pyrite occurred after burial; the large size of crystals suggests late diagenesis, perhaps seeded by early diagenetic pyrite crystallites produced by decay of ligamentary tissue. Extrinsic taphonomic factors include overgrowth of holdfasts by laminar stenolaemate bryozoans and other echinoderm attachment structures. Diploporite holdfasts are not bored and are absent on microbioherms. Taphonomic data indicate the time-averaged nature of this hardground and its diploporite assemblage and permit prediction of similar occurrences at major flooding surfaces.

Description: In the Variscan fold belt of Morocco, the Jebilet massif is characterized by Palaeozoic metasedimentary rocks intruded by syntectonic magmatism that includes an ultramafic–granitoid bimodal association and peraluminous granodiorites emplaced c . 330 Ma, intruded by younger leucogranites c . 300 Ma. The mafic–ultramafic rocks belong to a tholeiitic series, and display chemical and isotopic signatures consistent with mixing between mantle-derived and crust-derived magmas or assimilation and fractional crystallization. The granites within the bimodal association are mainly metaluminous to weakly peraluminous microgranites that show characteristics of A 2 -type granites. The peraluminous, calc-alkaline series consists mainly of cordierite-bearing granodiorites enclosing magmatic microgranular enclaves and pelitic xenoliths. Detailed element and isotope data suggest that the alkaline and the peraluminous granitoids were formed in the shallow crust (〈30 km) by partial melting of tonalitic sources at high temperatures (up to 900°C) and by partial melting of metasedimentary protoliths at relatively low temperatures ( c . 750°C), respectively. Mixing between the coeval mantle-derived and crust-derived magmas contributed to the large variation of initial Nd values and initial Sr isotopic ratios observed in the granitoids. Further contamination occurred by wall-rock assimilation during ascent of the granodioritic plutons to the upper crust. The ultramafic–granitoid association has been intruded by leucogranites that have high initial Sr isotopic ratios and low initial Nd values, indicating a purely crustal origin. The heating events that caused emplacement of the Jebilet magmatism are related to cessation of continental subduction and convective erosion/thinning of the lithospheric mantle during plate convergence.

Description: The lower bathyal Ocean Drilling Program Hole 1261A was sampled near an upper Quaternary oxygen minimum zone (OMZ). Glauconite, the percentage of the foraminiferal assemblage as benthic specimens and assemblage composition were used to investigate the behaviour of the OMZ. Benthic foraminifera and glauconite were comparable with the upper margin of the modern OMZ off California. The percentage abundances of U. peregrina and C. laevigata were on the Demerara Rise negatively correlated, the proportional abundance of U. peregrina increasing upwards through the section. This reflects variations in proximity to the upper margin of the OMZ. This might reflect either crustal subsidence or long-term shallowing of the OMZ during the earlier late Quaternary. Neither hypothesis can be accepted unequivocally. The purported subsidence can be ascribed to crustal loading by the Amazon and Orinoco deep-sea fans, but this would require that the palaeodepth to the top of the OMZ remains constant across several glacial–interglacial cycles. In contrast, it is difficult to envisage any mechanism that could have caused progressive shallowing of the OMZ across several glacial–interglacial cycles. The epifaunal Planulina wuellerstorfi is related to more oxic waters and enhanced current action. This suggests that intervals with more abundant P. wuellerstorfi were somewhat less dysoxic than those with few. These intervals approximate to those with more abundant C. laevigata. Superimposed on this low-frequency signal is a higher-frequency signal, indicated by a between-sample assemblage turnover index (ATIs) that might prove useful for long-range sequence stratigraphic correlation at bathyal depths.

Description: The robust spines and sclerites of the early to middle Cambrian ‘mollusc’ Wiwaxia are ubiquitous in suitably preserved deposits, but are strikingly absent from the Chengjiang Lagerstätte (Cambrian Stage 3, Yunnan Province, SW China). Here we provide the first record of Wiwaxia sclerites from this rich deposit, extending the record of the genus to the earliest Cambrian Series 2. This reinforces the cosmopolitan distribution of this iconic Cambrian lophotrochozoan and demonstrates the strong faunal continuity that unites distant Cambrian Lagerstätten.

Description: Andros is a key island for understanding both the timing of high-pressure–low-temperature (HP-LT) metamorphism and the dynamics of crustal-scale detachment systems exhuming high-grade units in the Cyclades (Greece). Using phengite 40Ar–39Ar geochronology coupled with thermobarometry, as well as data from literature, we constrain the pressure–temperature–time (P-T-t) paths of the Makrotantalon and Attic–Cycladic Blueschist units on Andros. Peak conditions of the HP-LT episode in the Makrotantalon unit are 550°C and 18.5 kbar, dated at 116 Ma. We correlate this episode with Early Cretaceous blueschist facies metamorphism recognized in the Pelagonian zone of continental Greece. This is a new argument favouring a Pelagonian origin for the Makrotantalon unit. In the Attic–Cycladic Blueschist unit, the P-T-t path is characterized by: (1) exhumation after peak conditions in HP-LT conditions between 55 and 35 Ma; (2) isobaric heating at 7 kbar until 30 Ma; and (3) isothermal decompression until 21 Ma. This thermal evolution and timing are similar to those of the neighbouring Tinos Island, emphasizing major thermal re-equilibration at the transition between stable and retreating subduction. Modifications of the crustal thermal state played a major role in the evolution of the North Cycladic Detachment System, below which Andros HP-LT units were exhumed.

Description: The Oligocene sedimentary succession in the eastern North Sea is revised and re-interpreted by applying new state-of-the-art reflection seismic data integrated with new bio- and Sr-stratigraphy data from three key wells in the study area. The Oligocene succession in the eastern North Sea is divided into four transgressive–regressive (T-R) sequences, characterized by non-accretional and/or aggradational transgressive systems tracts and prograding regressive systems tracts. Detailed studies of three wells, including biostratigraphy and Sr analysis, constrain the age relationships between the T-R sequences. Internal clinoform geometry indicates that the sediments were sourced from the present southern Norwegian mainland to the north of the depositional area. The direction of progradation shifted from being SE-directed in the earliest Rupelian (early Oligocene) to S- and SW-directed during Chattian time (late Oligocene). Rapid basin subsidence is indicated by the development of non-accretionary transgressive systems tracts, with subsequent progradation into water depths of hundreds of metres. The creation of accommodation space was out of phase relative to eustatic sea-level changes, and mainly controlled by regional-scale differential vertical movements where uplift and exposure of landmasses of the hinterland (southern Norway) occurred concurrently with basin subsidence. Halokinesis had an intra-basinal influence on the main sediment transport direction, but probably did not contribute much in creation of accommodation space.

Description: We thank Liu Jun for his comment on our recent paper (Wang et al. 2014) and are grateful for his calling our attention to this apparent contradiction, and we welcome the opportunity to reply. Based on the sensitive high-resolution ion microscope (SHRIMP) U–Pb zircon age for a volcanic tuff bed within the upper part of the Guanling Formation, we suggested in our study that the age of the fossil horizon of the Panxian fauna is 244 ± 1.3 Ma, which is 14 Ma earlier than the previously estimated age that Li, Rieppel & LaBarbera (2004) published in Science. However, Liu Jun argued that this conclusion is confused, that there is no 14 Ma difference and that there is agreement between the biostratigraphic data and the new radiometric age.

Description: High-resolution SIMS U–Pb dating of metamorphic zircons of the TTG gneisses, gneissic granitoid and amphibolites of the Lushan terrane, Taihua metamorphic complex, suggests that the metamorphism had taken place at least as early as ~1.96–1.86 Ga. These new dates, along with reference data, demonstrate that the southern and middle terranes of the Trans-North China Orogen had been involved in the continent–continent collision between the Western Block and the Eastern Block of the North China Craton. This orogenic process started as early as 1.96 Ga and lasted as late as 1.80 Ga.

Description: The Santa Eulália Plutonic Complex (SEPC), located in the Ossa Morena Zone (south Portugal), is composed of a medium- to coarse-grained pink granite (G0-type) and a central grey medium-grained biotite granite (G1-type). Available Rb–Sr data indicates an age of 290 Ma. An emplacement model for the SEPC is proposed, taking into account magnetic fabric, 2D gravity modelling and fluid inclusion planes studies. The G0 and G1 types demonstrate different magnetic behaviour: G0 is considered a magnetite-type granite and G1 is an ilmenite-type granite. The formation of G0 required oxidized conditions related to the interaction of mafic rocks with a felsic magma. The 2D gravity modelling and subvertical magnetic lineations show that the feeder zone of the SEPC is located in the eastern part of the pluton, confirming the role of the Assumar and Messejana Variscan faults in the process of ascent and emplacement. The magma emplacement was controlled by ENE–WSW planar anisotropies related to the final brittle stages of the Variscan Orogeny. The emplacement of the two granites was almost synchronous as shown by their gradational contacts in the field. The magnetic fabric however suggests emplacement of the G0-type first, closely followed by emplacement of the G1-type, pushing the G0 laterally which becomes more anisotropic towards the margin. The G1-type became flattened, acquiring a dome-like structure. The SEPC is a nested pluton with G0-type granite assuming a tabular flat shape and G1-type forming a rooted dome-like structure. After emplacement, SEPC recorded increments of the late Variscan stress field documented by fluid inclusion planes in quartz.

Description: 40Ar/39Ar in situ UV laser ablation of white mica, Rb–Sr mineral isochrons and zircon fission track dating were applied to determine ages of very low- to low-grade metamorphic processes at 3.5±0.4 kbar, 280±30°C in the Avalonian Mira terrane of SE Cape Breton Island (Nova Scotia). The Mira terrane comprises Neoproterozoic volcanic-arc rocks overlain by Cambrian sedimentary rocks. Crystallization of metamorphic white mica was dated in six metavolcanic samples by 40Ar/39Ar spot age peaks between 396±3 and 363±14 Ma. Rb–Sr systematics of minerals and mineral aggregates yielded two isochrons at 389±7 Ma and 365±8 Ma, corroborating equilibrium conditions during very low- to low-grade metamorphism. The dated white mica is oriented parallel to foliations produced by sinistral strike-slip faulting and/or folding related to the Middle–Late Devonian transpressive assembly of Avalonian terranes during convergence and emplacement of the neighbouring Meguma terrane. Exhumation occurred earlier in the NW Mira terrane than in the SE. Transpression was related to the closure of the Rheic Ocean between Gondwana and Laurussia by NW-directed convergence. The 40Ar/39Ar spot age spectra also display relict age peaks at 477–465 Ma, 439 Ma and 420–428 Ma attributed to deformation and fluid access, possibly related to the collision of Avalonia with composite Laurentia or to earlier Ordovician–Silurian rifting. Fission track ages of zircon from Mira terrane samples range between 242±18 and 225±21 Ma and reflect late Palaeozoic reburial and reheating close to previous peak metamorphic temperatures under fluid-absent conditions during rifting prior to opening of the Central Atlantic Ocean.

Description: Altered volcanic ash interbeds (bentonites) in the upper Katian of Baltoscandia indicate significant volcanic activity in neighbouring tectonically active areas. Katian bentonites in the East Baltic can be reliably correlated using sanidine phenocryst composition. Ratios of immobile trace elements TiO2, Nb, Zr and Th to Al2O3enable extension of the correlations to Scandinavia, where late diagenetic alterations could have caused recrystallization of sanidine phenocrysts. At least seven volcanic eruptions were recognized in Baltoscandian sections. Several bentonites found in deep-sea sediments are absent in shallow-sea sediments, indicating extensive breaks in sedimentation and erosion during late Katian and Hirnantian times. The areal distribution pattern of Katian bentonites in Baltoscandia indicates a volcanic source from the north or northwest (present-day orientation) from the margins of the Iapetus Palaeo-Ocean. Signatures of ultra-high-pressure metamorphism in the Seve Nappe (Central Sweden) and intrusions in the Helgeland Nappe Complex in Central Norway have been proposed as potential sources of the magmas that generated the volcanic ashes deposited in the East Baltic in Katian times. Geochemical similarities between Baltoscandian and Dob's Linn bentonites from southern Scotland suggest a common volcanic source in Katian times.

Description: Root-associated stalactites (rootsicles) in Galeria da Queimada lava tube have a mineralogical composition and developmental association with microbes that render them unique. Samples were examined by X-ray diffraction, micro-Raman spectrometry and scanning electron microscopy/X-ray energy-dispersive spectroscopy. Three types of rootsicle were defined: incipient; hard (white and red); and black spongy. The incipient rootsicles still contained rotten organic material and showed the beginning of mineralization by allophane. The white hard and black spongy types were also composed of allophane, while the red hard type was composed of hydrous ferric oxi-hydroxide minerals (HFO). The allophane and HFO in the andisol covering the cave roof precipitated out of the dripwater running along the roots to form the studied rootsicles. All three types of rootsicle showed black layers, coatings, spots or patches composed of manganese oxide minerals and, occasionally, hisingerite (iron (III) phyllosilicate). An alternation of organic precipitation caused by filamentous bacteria and inorganic precipitation (the latter facilitated by pH changes in the dripwater and the cave's temperature) built up both the porous and compact rings observed in the white and red hard rootsicles. The largely straight filaments seen in the porous rings of the white hard rootsicles may be indicative of the previous presence ofLeptothrixspp., while the helical morphologies seen in the red hard rootsicles may be indicative of that ofGallionellaspp. The manganese oxide minerals detected probably formed via microbial activity. This study reflects the important role of filamentous bacteria in rootsicle formation, independent of their mineralogy.

Description: 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.

Description: The planktonic foraminifera assemblage across the Global Boundary Stratotype Section and Point (GSSP) for the base of the Cenomanian Stage defined at Mont Risou (Haute-Alpes in France) is here restudied to clarify the identification and stratigraphic distribution ofThalmanninella globotruncanoides( =Rotalipora globotruncanoidesSigal, 1948) andPseudothalmanninella tehamaensis( =Rotalipora tehamaensisMarianos & Zingula, 1966) whose appearance levels are primary and secondary criteria for placing the Albian/Cenomanian boundary. Since the ratification of the GSSP in 2002, the identification of the foraminifera index species across the Albian/Cenomanian boundary has been reported to be sometimes difficult either because of their rarity or uncertainty in the taxonomic identifications. We discuss the taxonomic status ofThalmanninella brotzeniSigal 1948, a species regarded for a long time to be a junior synonym ofTh. globotruncanoides, through images of Sigal's type materials deposited at the Musée National d’Histoire Naturelle (Paris), and elucidate the taxonomically important characters that enable unequivocal identification ofTh. brotzeni, Th. globotruncanoidesandPs. tehamaensis. Planktonic foraminifera marker species from Mont Risou are compared with well-preserved specimens from Blake Nose Plateau (ODP 171B, North Western Atlantic Ocean) to verify the reliability and stratigraphic distribution of these marker taxa outside the Mediterranean Tethyan area.

Description: The basement of the Central Pontides, and by implication that of Crimea, consists of pre-Permian low-grade metaclastic rocks intruded by latest Permian – Early Carboniferous (305–290 Ma) granitoids. Further up in the stratigraphic sequence are Triassic limestones, which are now preserved as olistoliths in the deformed Upper Triassic turbidites. New conodont and foraminifera data indicate an Anisian to Carnian (Middle to Late Triassic) age for these hemi-pelagic Hallstatt-type limestones. The siliciclastic turbidites surrounding the Triassic limestone contain the Norian (Late Triassic) bivalveMonotis salinaria; the same species is also found in the Tauric series in Crimea. The Upper Triassic flysch in the Central Pontides is locally underlain by basaltic pillow lavas and includes kilometre-size tectonic slices of serpentinite. Both the flysch and the serpentinite are cut by an undeformed acidic intrusion with an Ar–Ar biotite age of 162 ± 4 Ma (Callovian–Oxfordian). This indicates that the serpentinite was emplaced into the turbidites before Middle Jurassic time, most probably during latest Triassic or Early Jurassic time, and that the deformation of the Triassic sequence pre-dates the Middle Jurassic. Regional geological data from the circum-Black Sea region, including widespread Upper Triassic flysch, Upper Triassic eclogites and blueschists of oceanic crustal affinity, and apparent absence of a ‘Cimmerian continent’ between the Cretaceous and Triassic accretionary complexes indicate that the latest Triassic Cimmeride orogeny was accretionary rather than collisional and is probably related to the collision and accretion of an oceanic plateau to the southern active margin of Laurasia.

Description: Three isolated limestone deposits and their fauna are described from a middle Eocene Flysch succession in northwestern Istria, Croatia. The limestones are identified as ancient methane-seep deposits based on fabrics and characteristic mineral phases, δ13Ccarbonatevalues as low as −42.2 ‰ and13C-depleted lipid biomarkers indicative of methane-oxidizing archaea. The faint bedding of the largest seep deposit, the great dominance of authigenic micrite over early diagenetic fibrous cement, as well as biomarker patterns indicate that seepage was diffusive rather than advective. Apart from methanotrophic archaea, aerobic methanotrophic bacteria were present at the Eocene seeps as revealed by13C-depleted lanostanes and hopanoids. The observed corrosion surfaces in the limestones probably reflect carbonate dissolution caused by aerobic methanotrophy. The macrofauna consists mainly of chemosymbiotic bivalves such as solemyids (Acharax), thyasirids (Thyasira) and lucinids (Amanocina). The middle Eocene marks the rise of the modern seep fauna, but so far the fossil record of seeps of this age is restricted to the North Pacific region. The taxa found at Buje originated during the Cretaceous Period, whereas taxa typical of the modern seep fauna such as bathymodiolin mussels and vesicomyid clams are absent. Although this is only a first palaeontological glimpse into the biogeography during the rise of the modern seep fauna, it agrees with biogeographic investigations based on the modern vent fauna indicating that the dominant taxa of the modern seep fauna first appeared in the Pacific Ocean.

Description: The Central Asian Orogenic Belt is an accretionary orogen with many distinct terranes including the Chinese Central Tianshan, whose Precambrian tectonic affinity is not yet clearly known. We present Precambrian age spectra of inherited/xenocrystic zircons from magmatic rocks in the Chinese Central Tianshan, collected from published papers. The age patterns are dominated by zircons with ages ranging from 3261 to 541 Ma. These spectra provide robust clues regarding the Precambrian affinity of the Chinese Central Tianshan. The age spectra record two major tectonothermal events, represented by salient age peaks of c. 950 and 900 Ma within the ‘Grenville Orogeny’ period, and age peaks at c. 750 and 630 Ma, synchronous with magmatic events corresponding to Rodinia break-up. These results are consistent with the hypothesis that the Chinese Central Tianshan was part of the Tarim craton during Precambrian time as well as documenting its incorporation into, and separation from the Rodinia landmass.

Description: The uppermost Famennian – lowermost Tournaisian interval has been analysed in detail using biostratigraphy, sedimentology, magnetic susceptibility and geochemistry in a reference section of the relatively shallow carbonate ramp environment within the Pomeranian Basin. High-resolution biostratigraphic study, based on miospores, allows recognition of the standard western Europeanlepidophyta–nitidus(LN) andverrucosus–incohatus(VI) zones, as well as theConvolutispora majorZone, a local Pomeranian equivalent of the European standardhibernicus–distinctus(HD) Zone. The sedimentary succession and specific phenomena recognized close to the Devonian/Carboniferous boundary, such as fluctuations in water column euxinia, wildfire evidence, relative sea-level changes and perturbations of the carbon cycle reflected by positive carbon excursions, display a pattern partly similar to that observed in many areas in Europe during the Hangenberg Event, although the Hangenberg Black Shale horizon is not developed here. These important microscale environmental perturbations were observed not only within the Famennian LN miospore Zone but in a wide interval between the LN and the lowermost localConvolutispora majormiospore zones ( = lower part of HD standard miospore Zone). It is still uncertain whether the recognized event(s) were connected solely with the Hangenberg Event, which was possibly complex and multi-phased as is sometimes suggested, or whether they represent a succession of regionally limited, post-Hangenberg events. This question needs to be further investigated on broader stratigraphic and geographical scales.

Description: The North Singhbhum Mobile Belt (NSMB) is a 200 km long, curved Proterozoic fold–thrust belt that skirts the northern margin of the Archean Singhbhum Craton of NE India. The Singhbhum Shear Zone (SSZ) developed between the Dhanjori and Chaibasa formations near the southern margin of the NSMB and represents an important Cu-U-P metallotect. A SHRIMP U–Pb zircon date of 1861±6 Ma, obtained for the syn- to post-kinematic Arkasani Granophyre that has intruded the SSZ, provides a minimum age for the prolonged tectonic activity and mineralization along the SSZ and for the time of closure of the Chaibasa and Dhanjori sub-basins. The Dalma Volcanic Belt, a submarine rift-related bimodal mafic-felsic volcanic suite, forms the spine of the NSMB. A SHRIMP U–Pb zircon igneous crystallization date of 1631±6 Ma was obtained for an unfoliated felsic volcanic rock from the base of the Dalma volcanic sequence. These new findings suggest that the different sub-basins in the NSMB evolved diachronously under contrasting tectonic environments and were juxtaposed during a later orogenic movement.

Description: Burlingia balangensissp. nov. from the lower Cambrian of South China represents the earliest species of this genus, and suggests that the genus may have originated in South China. A revision of the genus shows thatB. primitivaandB. obscuracan be used in order to indentify the base of the Cambrian Stage 5 when other trilobites are absent because their last appearance datum (LAD) coincides with the first appearance datum (FAD) ofOryctocephalus indicus. Available palaeogeographic and palaeoclimatic models suggest five major palaeocurrents during Cambrian times which could control the migration patterns of theBurlingiaclade from South China to Baltica.

Description: The Mingshui–Jilasitai–Suolun area, located in the central part of the Great Xing’an Range, is characterized by large volumes of alkali feldspar granites. However, the formation time and tectonic setting of these rocks remains controversial owing to a lack of precise geochronological and detailed geochemical data. In this paper, we report new SIMS U–Pb zircon ages and mineralogical, petrographical and geochemical data for Lower Cretaceous alkali feldspar granites from the Mingshui–Jilasitai–Suolun area. The SIMS zircon dating results indicate that these granites formed at 133.6–135.9 Ma. The mineralogical, petrographical and geochemical data show that these granitic rocks belong to highly fractionated I-type granites. Combined with the regional geology data, we propose that the formation of the Lower Cretaceous alkali feldspar granitic rocks was related to an extension induced by delamination of the lithosphere that arose from subduction of the Palaeo-Pacific plate.

Description: The Diguva Sonaba area (Vishakhapatnam district, Andhra Pradesh, South India) represents part of the granulite-facies terrain of the Eastern Ghats Mobile Belt. The Precambrian metamorphic rocks of the area predominantly consist of mafic granulite (±garnet), khondalite, leptynite (±garnet, biotite), charnockite, enderbite, calc-granulite, migmatic gneisses and sapphirine–spinel-bearing granulite. The latter rock type occurs as lenticular bodies in khondalite, leptynite and calc-granulite. Textural relations, such as corroded inclusions of biotite within garnet and orthopyroxene, resorbed hornblende within pyroxenes, and coarse-grained laths of sillimanite, presumably pseudomorphs after kyanite, provide evidence of either an earlier episode of upper-amphibolite-facies metamorphism or they represent relics of the prograde path that led to granulite-facies metamorphism. In the sapphirine–spinel-bearing granulite, osumilite was stable in addition to sapphirine, spinel and quartz during the thermal peak of granulite-facies metamorphism but the assemblage was later replaced by Crd–Opx–Qtz–Kfs-symplectite and a variety of reaction coronas during retrograde overprint. Variable amounts of biotite or biotite+quartz symplectite replaced orthopyroxene, cordierite and Opx–Crd–Kfs–Qtz-symplectite at an even later retrograde stage. Peak metamorphic conditions of c. 1000°C and c. 12 kbar were computed by isopleths of XMg in garnet and XAl in orthopyroxene. The sequence of reactions as deduced from the corona and symplectite assemblages, together with petrogenetic grid and pseudosection modelling, records a clockwise P–T evolution. The P–T path is characteristically T-convex suggesting an isothermal decompression path and reflects rapid uplift followed by cooling of a tectonically thickened crust.

Description: U–Pb zircon ages from volcanic rocks of Early Permian age (Southern Alps, Lombardy), associated with fault-controlled transtensional continental basins, were determined with the laser ablation (LA)-ICP-MS technique. Four samples were collected at the base and at the top of the up to 1000 m thick volcaniclastic unit of the Cabianca Volcanite. This unit pre-dates the development of a sedimentary succession that still contains, at different stratigraphic levels, volcanic intercalations. Age results from a tuff in the basal part of the unit constrain the onset of the volcanic activity to 280 ± 2.5 Ma. Ignimbritic samples from the upper part of the unit show a large scatter in the age distribution. This is interpreted as the occurrence of antecrystic and autocrystic zircons. The youngest autocrystic zircons (c. 270 Ma) are thus interpreted as better constraining the eruption age, constraining the duration of the volcanic activity in the Orobic Basin to about 10 Ma. The new geochronological results compared with those of other Early Permian basins of the Southern Alps reveal important differences that may reflect (1) a real time-transgressive beginning and end of the volcanic activity or (2) the complex mixing of antecrystic and autocrystic zircon populations in the analysed samples.

Description: The Weeks Formation preserves a diverse, yet largely undescribed, exceptionally preserved fauna of late Guzhangian age. Here I describeNotchia weugigen. et sp. nov., a new arthropod characterized by a short cephalon, a trunk with 12 tergites and weakly differentiated into two morphological regions, and a spine-bearing rectangular telson. This combination of characters is incompatible with its assignment to any known groups. The new taxon also adds to examples of convergent evolution of ramified digestive glands in arthropods, possibly as an adaptation to infrequent feeding.

Description: We use detrital provenance data from Cambrian sandstones to examine whether the Yangtze and Cathaysia blocks in South China were separated by an ocean during the Cambrian period. Zircons from the Cambrian sandstones exhibit a dominant ~ 800 Ma age peak in the central Yangtze Block, being sourced from the western Yangtze Block, whereas a ~ 980 Ma peak dominates in the northwestern Cathaysia Block, being sourced from an exotic continent once connected to Cathaysia. A mixed provenance with both age peaks is found in Cambrian sandstones from the southeastern Yangtze Block, indicating that detritus can travel from the Cathaysia Block to the Yangtze Block, and therefore arguing against the existence of a broad Cambrian ocean.

Description: The Palaeozoic rocks of the Dingle Peninsula provide a record of the evolution of the Caledonides, Acadides and Variscides. The succession ranges from Early Ordovician deep-water sediments, through Silurian shallow marine to non-marine sediments and volcanic rocks to an Old Red Sandstone (ORS) succession topped by Carboniferous marine shales. Comparison of structural styles in the unconformity-bounded groups, together with a detailed analysis of fault zones, allows the tectonic history to be deduced. The older rocks record Caledonian processes on the margin of Avalonia during Early Ordovician time and convergence then soft collision with Laurentia during Silurian time. The Dingle Basin was developed during the late Silurian – Early Devonian transtension in the Iapetus suture zone and was inverted in the latest Emsian Acadian orogenic episode. Post-Dingle Group ORS groups in the north of the peninsula were deposited in a syn-rift footwall block to the main Munster Basin. The Acadian transpressional and Munster Basin extensional structures were reactivated or overprinted in the Variscan deformation such that Acadian folds are transected by Variscan cleavage in both plan and vertical views. After Iapetus closure, changes in the tectonic regime are believed to be a result of adjustments in the geometry of subduction of the Rheic Ocean.

Description: The olistostromes form two belts within the Pieniny Klippen Belt (PKB) in the Northern Carpathians. They mark an early stage of the development of the accretionary prism. The first belt was formed during Late Cretaceous time as a result of subduction of the southern part of the Alpine Tethys. The fore-arc basin originated along this subduction zone, with synorogenic flysch deposits. Huge olistoliths deposited within the Cretaceous–Palaeogene flysch of the Złatne Basin, presently located in the vicinity of the Haligovce village (eastern Slovakia), provide a good example of the fore-arc olistostrome setting. The second belt is related to the movement of the accretionary prism, which overrode the Czorsztyn Ridge during Late Cretaceous–Paleocene time. The destruction of this ridge led to the formation of submarine slumps and olistoliths along the southern margin of the Magura Basin. The Upper Cretaceous – Paleocene flysch sequences of the Magura Basin constitute the matrix of olistostromes. The large Homole block in the Jaworki village represents the best example of the Magura Basin olistolith. Numerous examples of olistoliths were documented in western Slovakia, Poland, eastern Slovakia and Ukraine. The olistostromes formed within the Złatne and Magura basins orginated during the tectonic process, forming the olistostrome belts along the strike of the PKB structure.

Description: A Lower Devonian silicified ostracod fauna has been recovered from limestone interbeds in the Büyükdere section of the Kozyatağı Member of the Pendik Formation. Forty-one species belonging to 33 genera have been recognized. Twenty-three are already known, and 15 are described in open nomenclature. One genus and three species (Omerliella rectangulatagen. et sp. nov.,Microcheilinella istanbulensissp. nov. andRoundyella goekchenaesp. nov.) are described. Silicified larval stages of trilobites, agglutinated foraminifers and conodonts co-occur with the ostracods. The ostracod assemblages are ‘mixed faunas’, between the epineritic Eifelian Mega-Assemblage, representative of high-energy environments, and the basinal Thuringian Mega-Assemblage, representative of low-energy environments. The conodont faunas of the Pendik Formation represent theserotinus,patulusandpartitusbiozones of the late Emsian – earliest Eifelian. The Emsian ostracods of NW Turkey show numerous species-level links between the Western Pontides (Istanbul Terrane) and assemblages of contemporaneous faunas of the Cantabrian Mountains (Spain), Morocco and Thuringia (Germany), and of similar biofacies. This supports the notion that the Istanbul Terrane, Armorican terrane-collage and northern margins of Gondwana were in geographical proximity in late Early Devonian time.

Description: The uppermost metavolcanic layer of the Cambro-Ordovician Ollo de Sapo Formation, the largest accumulation of pre-Variscan igneous rocks in the Iberian Peninsula, have been dated in its northernmost part using U–Pb SHRIMP-RG zircon age techniques at 479.0 ± 4.7 Ma. The age obtained is the youngest age found so far in the metavolcanic facies of Ollo de Sapo Formation and represents the cessation of the rifting-related Cambro-Ordovician Ollo de Sapo volcanism at the northernmost tip of the Iberian Peninsula. Our results show that the Cambro-Ordovician volcanism in the NW of the Iberian Peninsula is not as short-lived as previously thought and confirm the correlation between the Cambro-Ordovician volcanic sequences that crop out in the Central Iberian Zone and the French Southern Armorican Massif. Finally, our study suggests that the cessation of the Cambro-Ordovician volcanism along the Ibero-Armorican Arc was synchronic or, less probably, slightly diachronic with younger ages towards the north (in present-day geographical coordinates).

Description: A new genus and new species of primitive eucryptodiran turtle, Phunoichelys thirakhupti gen. et sp. nov., is described on the basis of shell remains from the lower part of the Phu Kradung Formation, at Phu Noi locality, Kalasin Province, NE Thailand. It is assigned to Xinjiangchelyidae on the basis of the marginals covering the lateral end of the costals and the anal scutes invading the hypoplastra. The new taxon is further characterized by a low and rounded carapace without a cervical notch; the whole carapace and plastron covered with a clear ornamentation consisting of tiny irregular vermiculated furrows; a complete neural series that reaches the suprapygal; a very wide and short cervical scute; relatively wide vertebral scutes; and a long first thoracic rib that extends along the full width of the first costal. The sutured plastron/carapace connection and the marginals covering the lateral end of the second to seventh costals suggest that the turtles from Phu Noi may be related to some primitive xinjiangchelyids from the Sichuan Basin. The discovery of a xinjiangchelyid turtle in the lower part of the Phu Kradung Formation supports a Late Jurassic age for that part of the formation.

Description: Marine invertebrate borings are very rare in crystalline rocks, providing evidence of particular strategies producers use to colonise these unfavourable substrates. In the Sorbas Basin (Almería, southern Spain), Upper Miocene transgressive successions contain blocks of metamorphic and igneous rocks of the Nevado–Filabride Complex of the Betic Cordillera. Ichnological analysis of the embedded blocks shows the presence of two types of macroborings located in gneiss boulders, revealed to be an extraordinary case worldwide. The most abundant are regular hemispherical depressions ascribed reservedly to the well-known, mostly bivalve boringGastrochaenolites. The second one is a pouch-like depression, tapering downward, elliptical in outline, and clearly different to other non-circular-in-outline, pouch-shaped macroborings. Thus, a new ichnogenus and ichnospeciesCuenulites sorbasensishas been defined. According to the overall shape, an endolithic or semi-endolithic bivalve using chemical means to bore is suggested as the tracemaker. Colonisation could be determined by sea-level coastal dynamics, with decreasing energy during advancing transgression allowing boring, which was then stopped due to supply of fine-grained sediment that killed the borers.

Description: 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.

Description: We amend the taxonomy and provide new anatomical information on the hadrosaurid dinosaur Saurolophus morrisi (upper Maastrichtian Moreno Formation, central California, USA) derived from full preparation of the referred skull roof. The cranial morphology of this species is distinct enough to justify the new combination Augustynolophus morrisi gen. nov. The morphology of the nasals and surrounding cranial bones indicates that A. morrisi sported a solid nasal crest ending in an elongate triangular plate that extended above the skull roof. Autapomorphies include a crescentic base of the frontal caudodorsal process and extension of the process caudal to the frontal ‘dome’; distal end of nasal crest with knob-like process inflected rostrally; circumnarial depression lightly incised and weakly emarginated, adjacent to caudolateral margin of nasal and occupying two-thirds the width of lateral surface of distal region of crest; and caudal surface of distal nasal crest subrectangular. We formally establish the new tribe Saurolophini consisting of Prosaurolophus, Augustynolophus and Saurolophus. Saurolophin synapomorphies include a premaxilla with broad arcuate contour of rostrolateral region of thin everted oral margin and flat and steeply inclined occlusal surface of dentary dental battery, among other characters. Saurolophin crests evolved towards increasing caudodorsal length, along with caudal extension of the circumnarial fossa and involvement into the crest of adjacent facial elements. Augustynolophus is the second described genus of North American late Maastrichtian hadrosaurids. Its recognition implies a greater diversity among late Maastrichtian dinosaur faunas than previously recognized and is congruent with hypotheses of endemism and/or provinciality during Late Cretaceous time.

Description: The Neoproterozoic Hedmark Basin in the Caledonides of South Norway was formed at the western margin of the continent Baltica by rifting 750–600 Ma ago. The margin was destroyed in the Caledonian Orogeny and sedimentary basins translated eastwards. This study uses provenance analysis to map the crustal architecture of the pre-Caledonian SW Baltican margin. Conglomerate clasts and sandstones were sampled from submarine fan, alluvial fan and terrestrial glacigenic sedimentary rocks. Samples were analysed for U–Pb isotopes and clast samples additionally for Lu–Hf isotopes. The clasts are mainly granitesc. 960 Ma and 1680 Ma old, coeval with the Sveconorwegian Orogeny and formation of the Palaeoproterozoic Transscandinavian Igneous Belt (TIB). Mesoproterozoic (Sveconorwegian) ages are abundant in the western part of the basin, whereas Palaeoproterozoic ages are common in the east. Lu–Hf isotopes support crustally contaminated source for all clasts linking them to Fennoscandia. Detrital zircon ages of the sandstones can be matched with those from the granitic clasts except for ages within the range 1200–1500 Ma. These ages are typically found in the present-day Telemark, SW Norway. The sandstones and conglomerate clasts in the western part of the Hedmark Basin were sourced from the Sveconorwegian domain in the present SW Norway or its continuation to the present-day NW. The conglomerate clasts in the eastern part of the Hedmark Basin were sourced mainly from the TIB domain or its northwesterly continuation. The Hedmark Basin was initiated within the boundary of two domains in the basement: the TIB and the Sveconorwegian domains.

Description: During Early, as proposed by the International commission on stratigraphy Pleistocene times, interacting fluvial and aeolian processes constructed wide alluvial plains over an evaporite-dominated Miocene substratum in the central Ebro Basin. An exceptional site where these deposits show faults, folds, diapirs, karst structures and unconformities has been studied in detail. Analysis of particular structures demonstrates the interaction by that time of tectonic faulting, diapirism, karstification and sedimentation in an area where deformation was traditionally linked to the presence of underlying evaporites, without proposing any precise mechanism. Multiple approaches (sedimentology, structural geology and geophysics) have been used in order to discriminate the origin of each type of structure as well as to understand the interaction between different processes. Numerous normal faults and fractures of variable size are consistent with the regional stress field. Pleistocene deposits are pierced by diapirs of Miocene evaporites and disrupted by karst structures with different geometries (tubular, funnel and vault), both partially controlled by tectonics. The example described is proposed as an analogue model that could successfully illustrate evolution patterns of basins of potential interest for petroleum geology where similar processes have actuated, resulting in complex stratigraphical architectures.

Description: The role of travertine fissure-ridges in reconstructing tectonics and related earthquakes is a challenging issue of recent debate directed at delineating historical/prehistorical seismic records. Indeed, direct measurements on a travertine fissure-ridge immediately after a seismic event have never been previously performed. We describe the co- and post-seismic effects of a M = 3.6 earthquake on fluid flow and travertine deposition in a geothermal area of Tuscany (Italy). Direct observation allows us to demonstrate that thermal spring (re)activation is directly influenced by transient seismic waves, therefore providing a basis for reconstructing seismic events in the past.

Description: Alicja M. Lacinska and Michael T. Styles reply: We appreciate the comment by C. R. M. Butt on the publication by Lacinska & Styles (2013) on the silicified serpentinites described from the Hajar Mountains in the United Arab Emirates. This comment is based on his very extensive knowledge of laterites and regoliths from ancient shield areas around the world; the degree to which this knowledge is directly applicable to the rocks formed at the margins of a recently uplifted mountain range, as described in the original paper, is debatable.

Description: Conodonts are rare in the Permian carbonates of Indochina but abundant conodonts and ostracodes have been obtained from turbiditic limestones of the Permian E-Lert Formation along with radiolarians from overlying cherts, all deposited on the margins of the interplatform Nam Duk Basin. Conodonts are typically Tethyan and are very similar to faunas from Sicily and south China. They includeHindeodus gulloides,Pseudohindeodus oertlii,Mesogondolella siciliensisandSweetognathus subsymmetricuswhich indicate a probable late Kungurian – Roadian age range although a Wordian age cannot be excluded.M. siciliensis, which has a high blade and small cusp supposedly typical of warm-water conodonts, is found in deep (

Description: We report two newly identified Ordovician ophiolite belts in west Junggar, NW China: Tajin–Tarbahatai–Kujibai–Honguleleng (TTKH) and Tangbale–Baijiantan–Baikouquan (TBB) ophiolitic belts. These two ophiolitic belts provide constraints for the Palaeozoic reconstruction of Central Asia and the geological evolution of this region. The TTKH and TBB ophiolitic belts are dismembered parts of different ophiolitic belts which represent relics of Ordovician oceanic floor; they subducted to the north under the Chingiz–Tarbahatai arc and to the south under the Junggar plate, respectively. The Baijiantan–Baikouquan ophiolite mélanges comprise the major part of the TBB. Flat rare Earth element (REE) patterns with positive Eu anomalies and insignificant depletion of high-field-strength elements (HFSE) relative to melts of primitive mantle suggest a mid-ocean-ridge basalt (MORB) origin for the metagabbro. Lherzolite samples define a Sm–Nd isotopic isochron with age of 474 Ma andɛNd(t)of +8.9. Lherzolite samples with positiveɛNd(t)values of +8.8 to +9.1 and initial87Sr/86Sr ratios of 0.7037–0.7040 are rather homogeneous in Sr–Nd isotopic composition, whereas metagabbro samples show wider Sr–Nd isotopic compositional ranges withɛNd(t)of +5.9 to +11.0. The Sm–Nd isotopic isochron age (c.380 Ma) for garnet amphibolite samples, consistent with a zircon U–Pb age (c.385 Ma) for metagabbro, represents a magmatic event prior to subduction. Thermodynamic calculations for garnet amphibolite yield a clockwise pressure–temperature path with peak metamorphic condition ofc.15 kbar and 520–560°C at 342 Ma, indicating a subduction-channel setting. The Rb–Sr isochron ages (335 Ma, 333 Ma) for metagabbro represent a metamorphic event during exhumation.

Description: Eggshell fragments attributed to large birds have been known from the Palaeogene of southern France for half a century, but reconstructing their original dimensions and identifying the birds that laid the eggs has been fraught with difficulties. On the basis of numerous newly collected specimens and using geometrical calculations, the original size of the thick-shelled eggs is reconstructed, showing that they were slightly larger than ostrich eggs, with a greatest length of 17.8 cm and a mean diameter of 12.0 cm in transversal section. The estimated volume is 1330.4 cm3. The fossil eggs from southern France are thus among the largest known avian eggs, being only surpassed byAepyornisand some moas. Estimated egg mass is about 1.4 kg. On the basis of egg mass, the body mass of the parent bird is estimated at between 135.4 kg and 156.4 kg, assuming that the hatchlings were precocial. These calculations are in good agreement with the dimensions and mass estimates for the Palaeogene giant birdGastornis, a probable anseriform, which lived in Europe at the time the eggs were laid. Other large Early Tertiary birds from Europe (Remiornis,Palaeotis) are too small to have laid these eggs. In all likelihood, the large eggs from the Palaeogene of southern France were laid by gastornithid birds.

Description: A volcanic tuff 1.0 m above the base of the Triebenreuth Formation in the Franconian Forest provides the first precise and biostratigraphically bracketed date within the traditional Middle Cambrian. The first illustration of fossils from the Triebenreuth Formation in this report and their discussion allow a more highly refined correlation within the Middle Cambrian. A weighted mean 206Pb–238U date of 503.14±0.13/0.25/0.59 Ma on zircons from this subaerial pyroclastic tuff was determined by U–Pb chemical abrasion isotope dilution mass spectrometry (CA-TIMS) techniques. At c. 6.0–7.0 Ma younger than the base of the traditional Middle Cambrian in Avalonia, the new West Gondwanan date from east-central Germany suggests that estimates of 500 Ma for the base of the traditional Upper Cambrian and 497 Ma on the base of the Furongian Series may prove to be too ‘old’. Biostratigraphically well-bracketed dates through most of the Middle Cambrian/Series 3 and below the upper Upper Cambrian/upper Furongian Series do not exist. An earlier determined 494.4±3.8 Ma date from the Southwell Group of Tasmania may actually prove to be a reasonable estimate for the age of the base of the traditional Upper Cambrian. Until high precision dates are determined on the base of the traditional Upper Cambrian and base of the Furongian Series, the rates of biotic replacements and geological developments and the durations of biotic zones in the Middle/Series 3 and Upper Cambrian/Furongian Series remain as ‘best guesses’.

Description: A thick Ordovician intra-rhyolitic palaeosol was studied to investigate the peculiarities of early Palaeozoic continental environments, shortly before the development of vascular plants, and to compare its pedogenic patterns with those of previously studied intra-basaltic profiles from the same succession. Well-defined K-eluviation from the top of the palaeosol is proportionally met by K-illuviation at the base of the profile, a pedogenic behaviour that was masked in the underlying intra-basaltic profiles due to subsequent eodiagenetic K-enrichment associated with rhyolite emplacement. Greater stability of K (and eventually Mg) than Si in the intra-rhyolitic profile suggests high pH soil water at the time of pedogenesis despite the low base contents of the acidic host rock, and despite evidence for humid weathering conditions. We also observe that, at the base and at the top of the profile, Al2O3/Zr ratios are substantially lower than those of the host rock, suggesting Al-leaching and therefore extreme weathering conditions, whereas the middle portion of the profile shows Al2O3/Zr ratios that are similar to those of the host rock, suggesting Al stability and therefore less extreme conditions. We interpret these variations in Al2O3/Zr ratios as signatures of a cyclic change from sub-humid periods during which Al was stable throughout the profile, to more humid periods with a well-defined seasonality, during which only the juvenile zone of weathering at the base of the profile could have developed sufficiently high pH during dry seasons for Al to be leached, leaving the Al2O3/Zr signatures from previous stages untouched higher in the profile.

Description: Systematic lithofacies, palaeocurrent, palaeomorphological and palaeohydrological analyses have provided detailed information about a hitherto unstudied river system of the Siwalik foreland basin of the Himalaya. Three distinct lithofacies associations, each representing a specific depositional setting, have been identified and named as ‘Facies Association A’, ‘Facies Association B’ and ‘Facies Association C’. The ‘Facies Association A’ comprises pebbly sandstone, cross-bedded sandstone, ripple-laminated sandy siltstone and bioturbated mudstone lithofacies and represents deposits of a braided channel. The ‘Facies Association B’ comprises cross-bedded sandstone, bioturbated mudstone, fine sandstone–mudstone alternation and lensoid to prismatic sandstone lithofacies and represents deposits of a channel, natural levee, crevasse-splay and flood plain of a meandering stream. The ‘Facies Association C’ comprises mottled siltstone–mudstone heterolith and fine sandstone lithofacies and represents deposits of the upland interfluve region. The braided stream had a maximum depth of 4.15 m, maximum width of 305 m and maximum discharge of 7045 cumec, whereas the meandering stream had a sinuosity of 1.26, maximum depth of 3.71 m, maximum width of 180 m and maximum discharge of 4070 cumec. The area had a regional radial outward flow pattern, but dominantly towards the SSW. However, the braided river had a bimodal flow pattern due to an active basement-high-induced bend along its course. A comparison of the sediment characters and morphological and hydrological parameters of these streams with those of the modern rivers of the Ganga (Gangetic) basin has enabled us to infer that this river system was located in the medial-distal megafan-interfan setting of the basin.

Description: New petrological and U–Pb zircon geochronological information has been obtained from intrusive plutonic rocks and migmatites from the Cap de Creus massif (Eastern Pyrenees) in order to constrain the timing of the thermal and tectonic evolution of this northeasternmost segment of Iberia during late Palaeozoic time. Zircons from a deformed syntectonic quartz diorite from the northern Cap de Creus Tudela migmatitic complex yield a mean age of 298.8±3.8 Ma. A syntectonic granodiorite from the Roses pluton in the southern area of lowest metamorphic grade of the massif has been dated at 290.8±2.9 Ma. All the analysed zircons from two samples of migmatitic rocks yield inherited ages from the Precambrian metasedimentary protolith (with two main age clusters at c. 730–542 Ma and c. 2.9–2.2 Ga). However, field structural relationships indicate that migmatization occurred synchronously with the emplacement of the quartz dioritic magmas at c. 299 Ma. Thus, the results of this study suggest that subduction-related calc-alkaline magmatic activity in the Cap de Creus was coeval and coupled with D2 dextral transpression involving NNW–SSE crustal shortening during Late Carboniferous – Early Permian time (c. 299–291 Ma). Since these age determinations are within the range of those obtained for undeformed (or slightly deformed) calc-alkaline igneous rocks from NE Iberia, it follows that the Cap de Creus massif would represent a zone of intense localization of D2 transpression and subsequent D3 ductile wrenching that extended into the Lower Permian during a transitional stage between the Variscan and Cimmerian cycles.

Description: D. R. Viete, G. J. H. Oliver and S. A. Wilde comment: First, we would like to commend Aoki et al. (2013) on a careful study and thought-provoking manuscript. Their interpretation of the Barrovian metamorphism as a fundamentally retrograde feature offers a refreshing alternative to the more conventional ‘peak-metamorphic’ models.

Description: At the southern boundary of the Rhodope Massif, NE Greece, the Kavala Shear Zone (KSZ) represents an example of the Eastern Mediterranean deep-seated extensional tectonic setting. During Miocene time, extensional deformation favoured syntectonic emplacement and subsequent exhumation of plutonic bodies. This paper deals with the strain-related changes in macroscopic, geochemical and microstructural properties of the lithotypes collected along the KSZ, comprising granitoids from the pluton, aplitic dykes and host rock gneisses. Moreover, we investigated the evolution of seismic anisotropy on a suite of granitoid mylonites as a result of progressive strain. Isotropic compressional and shear wave velocities (Vp,Vs) and densities calculated from modal proportions and single-crystal elastic properties at given pressure–temperature (P–T) conditions are compared to respective experimental data including the directional dependence (anisotropy) of wave velocities. Compared to the calculated isotropic velocities, which are similar for all of the investigated mylonites (average values:Vp~ 5.87 km s−1,Vs~ 3.4 km s−1,Vp/Vs= 1.73 and density = 2.65 g cm−3), the seismic measurements give evidence for marked P-wave velocity anisotropy up to 6.92% (at 400 MPa) in the most deformed rock due to marked microstructural changes with progressive strain, as highlighted by the alignment of mica, chlorite minerals and quartz ribbons. The highest P- and S-wave velocities are parallel to the foliation plane and lowest normal to the foliation plane. Importantly,Vpremains constant within the foliation with progressive strain, but decreases normal to foliation. The potential of the observed seismic anisotropy of the KSZ mylonites with respect to detectable seismic reflections is briefly discussed.

Description: A variety of host-fabric elements (HE) cut by cross-cutting elements (CE) in rocks defines flanking structures (FS) on mesoscopic and microscopic scales. There has been renewed interest in studying and classifying the FS for their morphologies, useful as shear sense indicators and geneses. Existing non-genetic morphologic parameters for the FS are reviewed, and two new classification schemes are presented. One of these is based on the nature of the CE and whether HE penetrates it. The other scheme takes account of all the potential combinations of drag/no drag and slip/no slip of the HE. Deciphering the shear sense of the rock body from FS is complicated because the angular relationship between the CE and the primary shear planes might be opposite to what is found between S- and C- ductile shear fabrics. Further, single CEs can curve and several similar FS occur in reverse forms. As with mineral fish, the shape asymmetries of microscopic CEs indicate the shear sense. Conjugate FS (with non-parallel CEs) with interfering perturbation fields around the CEs are more reliable shear-sense indicators than FS with single CE. During low but increasing bulk strains, FS may evolve from one type to another, e.g. from a- to s-type. At high strain, FS can resemble intrafolial or sheath fold. Whether the drag is normal or reverse depends fundamentally on the initial angle between the HE and the CE and the relative magnitudes of throw and vertical separation.

Description: The ancient marine limestone beds of the upper part of the Guanling Formation, Panxian County, Guizhou Province, SW China, yielded a wide range of high-diversity well-preserved marine reptiles such as the fully aquatic protorosaur with an extremely long neckDinocephalosaurus orientalis, the oldest mixosaurid ichthyosaurs and lariosaurs. However, there is no precise isotopic age to study the intriguing origin, evolution and emigration history of the important fauna. We report a sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon age for a volcanic tuff bed within the upper part of the Guanling Formation. The result indicates that the age of the fossil horizon is 244.0±1.3 Ma, 14 Ma earlier than the previously estimated age based on conodont evidence. We consider that the marine reptiles had a relatively rapid evolution during Middle Triassic time, some 8 Ma after the end-Permian mass extinction.

Description: Fifteen sandstone samples taken from pre-Cretaceous strata of the Yangtze Block are analysed to constrain the evolution of the South China Block, especially the assembly between the Yangtze and Cathaysia blocks. The results show that the maximum depositional age of the Neoproterozoic Lengjiaxi Group adjacent to the Cathaysia Block isc. 830 Ma, differing from that of the Kunyang and Dahongshan groups (〉 960 Ma) on the southwestern margin of the Yangtze Block. The detrital zircons from Palaeozoic samples from the Yangtze Block have similar age populations to those in the Cathaysia Block, and they may originate from the Cathaysia Block according to palaeogeographic, palaeocurrent and former research data. The detrital zircons of Middle–Upper Jurassic sandstones in the southwestern and central Yangtze Block yield dominant age populations at 2.0–1.7 Ga and subordinate groups of 2.6–2.4 Ga, 0.8–0.7 Ga and 0.6–0.4 Ga. The Upper Triassic strata may be derived from the southern Yangtze and North China blocks due to the collisions between the Indosina, South China and North China blocks, whereas the Jurassic sediments may be partly derived from uplift and erosion of the Jiangnan Orogen due to an intracontinental orogeny induced by Pacific subduction towards the Eurasia Plate. The detrital age spectra and provenance data for basement in the South China Block are analysed and compared with each other. The South China Block has affinity with Australia not only in the Columbia supercontinent but also in the Rodinia supercontinent. We infer the existence of an ancient orogen under the western Jiangnan Orogen, which may have occurred during the Columbia age, earlier than the Sibao orogeny. This is supported by seismic profile proof from the SinoProbe.

Description: C. R. M. Butt comments: In their recent paper, Lacinska & Styles (2013) described in detail the geological setting, mineralogy and petrology of ‘silicified serpentinite’ in the Hajar Mountains, United Arab Emirates (UAE). They note that their ‘silicified serpentinite’ is essentially the same unit as ‘birbirite’ and other informally named quartz-rich outcrops that overlie ultramafic rocks in this and other regions. Some authors have suggested such silicification to be hydrothermal in origin, but it is now generally accepted to be due to weathering. Lacinska & Styles (2013) concluded that ‘silicified serpentinite’ is a silcrete; this is correct, but it is a purely descriptive term and, without qualification, has no specific genetic implications other than being silica-cemented regolith (Butt & Zeegers, 1992; Eggleton, 2001). The materials illustrated are more correctly termed a silicified saprolite as they preserve the fabric of the protolith.