A well‐established Early–Middle Pleistocene marine sequence on south‐east Zakynthos island,western Greece: Magneto‐biostratigraphic constraints and palaeoclimatic implications

The chronostratigraphy of a long, onshore Early–Middle Pleistocene marine sedimentary sequence on the south‐east part of Zakynthos island, Greece, is presented. Correlation of the succession with the isotope record of Ocean Drilling Program Site 963 reveals the combined influence of tectonics and eustacy in this area. The sequence is divided into three formations by two main unconformities that apparently relate to sea‐level lowstands associated with two major northern hemisphere glaciations, those of marine isotope stages (MIS) 22 and 12. The Zakynthos sequence in many ways is comparable with the Italian Valle di Manche section. Magnetostratigraphic and rock magnetic analyses, supported by biostratigraphy, document the position of the Matuyama/Brunhes Chron boundary (0.77 Ma), the top and base of the Jaramillo Subchron (0.99–1.07 Ma), the Cobb Mountain Subchron (1.173–1.185 Ma) and the top of the Olduvai Subchron (1.78 Ma). The underlying strata are constrained exclusively by detailed nannofossil biostratigraphy extending at least to the lowermost Pleistocene at around 2.54 Ma and therefore certainly incorporating the base of the Olduvai Subchron (1.95 Ma) and possibly the Gauss/Matuyama Chron boundary (2.58 Ma). In addition, a remarkable increase in sedimentation rate (from 3.2 and 28 cm ka^?1 to 167 cm ka^?1) and hence resolution above the Matuyama/Brunhes boundary (Middle Pleistocene) reveals one short‐lived magnetic excursion, possibly 17a (0.66 Ma), within the normal polarity Brunhes Chron. Copyright © 2011 John Wiley & Sons, Ltd.     

Paleoenvironmental evolution of the Paratethys in the Slovenian Basin during the Late Paleogene

Several sections from the uppermost Eocene and Oligocene of northern Slovenia have been investigated with respect to sedimentary facies, foraminiferal assemblages, stable isotopes, carbonate microfacies, and palynology. The main objective was to reconstruct the paleoenvironmental history of the Paleogene Paratethys in this region of the eastern Alpine realm. The sediments exhibit a transgressive succession beginning with conglomerates, sandstones, and mudstones of fluvial and lacustrine origin followed by carbonates and muddy marls indicating marine conditions. The foraminiferal faunal changes from brackish to shallow marine to deeper marine assemblages and the distribution of the palynofloras corroborate the sedimentological results. Microfacies analysis of the limestones shows a wide variation of shallow water, generally mud-rich facies dominated by coralline algae, foraminifera, and corals. Microfaunas adapted to low-oxygen conditions indicate temporal sluggish bottom-water circulation which can be associated with high fresh-water fluxes. These results are discussed as reflecting both the global sea-level rise during the Early Oligocene and the regional tectonic and climatic evolution.     

Contribution of SHRIMP U–Pb zircon geochronology to unravelling the evolution of Brazilian Neoproterozoic fold belts

The South-American continent is constituted of three major geologic–geotectonic entities: the homonym platform (consolidated at the end of the Cambrian), the Andean chain (essentially Meso-Cenozoic) and the Patagonian terrains, affected by tectonism and magmatism through almost all of the Phanerozoic. The platform is constituted by a series of cratonic nuclei (pre-Tonian, fragments of the Rodinia fission) surrounded by a complex fabric of Neoproterozoic structural provinces.     

The Ferrara hard X-ray facility for testing/calibrating hard X-ray focusing telescopes

We will report on the current configuration of the X-ray facility of the University of Ferrara recently used to perform reflectivity tests of mosaic crystals and to calibrate the experiment JEM–X aboard Integral. The facility is now located in the technological campus of the University of Ferrara in a new building (named LARIX laboratory= ̳LARge ̳Italian ̳X-ray facility) that includes a tunnel 100 m long with, on the sides, two large experimental rooms. The facility is being improved for determining the optical axis of mosaic crystals in Laue configuration, for calibrating Laue lenses and hard X-ray mirror prototypes.     

Magnetic fabrics and rock magnetism of Proterozoic dike swarm from the southern São Francisco Craton, Minas Gerais State, Brazil

Magnetic fabric and rock magnetism studies were performed on 32 mafic dikes of a Proterozoic dike swarm from the southern São Francisco Craton (SFC; Minas Gerais State, SE Brazil). Magnetic anisotropies were determined by applying anisotropy of low-field magnetic susceptibility (AMS) and anisotropy of remanent magnetization (ARM). The latter was performed imposing both anhysteretic (total (AAR) and partial pAAR)) and isothermal remanence magnetizations (AIRM). Partial anhysteretic remanence anisotropy was performed based on remanent coercivity spectra from a pilot specimen of each site. In most sites, AMS is dominantly carried by ferromagnetic minerals, however, in some sites, the paramagnetic contribution exceeds 70% of bulk susceptibility. Rock magnetism and thin section analysis allow classifying the dikes as non-hydrothermalized and hydrothermalized. Magnetic measurement shows that the mean magnetic susceptibility is usually lower than 5×10⁻³ (SI). Ti-poor titanomagnetites up to pure magnetite pseudo-single-domain (PSD) grain sizes carry the majority of magnetic fabrics for non-hydrothermalized dikes whereas coarse to fine grained Ti-poor titanomagnetites carry the majority of magnetic fabrics for hydrothermalized dikes.Three primary AMS fabrics are recognized which are coaxial with ARM fabric, except for two dikes, from both non-hydrothermalized and hydrothermalized dikes. Normal AMS fabric surprisingly is not dominant (31%). The parallelism between AMS, pAAR_0–30, pAAR_30–60 and pAAR_60–90 fabrics in the hydrothermalized dikes indicates that magnetic grains formed due to late-stage crystallization or to remobilization of iron oxides due to hydrothermal alteration after dike emplacement have acquired a mimetic fabric coaxial with the primary fabric given by coarse-grained early crystallized Ti-poor titanomagnetites. This fabric is interpreted as magma flow in which the analysis of K_max inclination permitted the inference that the dikes were fed by horizontal or subhorizontal fluxes (K_max<30°). Intermediate AMS fabric is the most important (41%) in the investigated swarm. It is interpreted as due to vertical compaction of a static magma column with the minimum stress along the dike strike. ARM determinations for these sites also remained intermediate except for two dikes. In one of them, AIRM fabric resulted in normal AMS fabric while for the other AAR fabric resulted in inverse AMS fabric. A combination of AMS and ARM fabrics suggest that magmatic fabric for both dikes were overprinted by some late local event, probably related to Brasiliano orogenic processes after dike emplacement. InverseInverse AMS fabric is a minority (four dikes). ARM determinations also remained inverse suggesting a primary origin for inverse AMS fabric.     

‘Ageing out of place’: Experiences of resettlement and belonging among older Bhutanese refugees in New Zealand

Previous research has suggested that older refugees are particularly vulnerable to the stresses of resettlement in developed countries. However, to date the voices of older refugees have largely been missing from the body of refugee resettlement research. Using in‐depth interviews and thematic analysis, this paper explores the personal resettlement experiences of three former refugee elders from the Bhutanese community in Palmerston North. The findings suggest that culture, religion and social connections are of vital importance to the well‐being of these Bhutanese elders and their ability to foster a sense of self and place in a foreign land.     

Petrography and provenance of Laecanius Amphorae from Istria,northern Adriatic region,Croatia

Amphorae sherds from the Laecanius workshop of Roman Istria (10–5 B.C. and 78 A.D.), Croatia, were studied by integrating archaeological and geological techniques including fabric analysis, thin‐section petrography, X‐ray diffractometry (XRD), and heavy mineral analysis. The fabric of the sherds showed distinctive characteristics, permitting their classification and allocation into nine fabric groupss. Petrography revealed that quartz is the dominant clastic component, whereas carbonate is common as temper; XRD provided information on firing temperatures that ranged between 750 and 900°C. The sherds contain diverse heavy mineral suites with generally high epidote and garnet proportions; zircon is occasionally important. Garnet/epidote ratios and the presence of diagnostic species (pyroxene, hornblende) showed systematic variations that coincided with similar variations in fabric characteristics. Heavy mineral signatures of amphorae produced in other workshops proved essential in differentiating them from Laecanius sherds. A comparative heavy mineral analysis of terra rossa samples from the vicinity of the workshop indicated that terra rossa was the major source for the paste. Differences observed in the heavy mineral composition of the sherds and terra rossa were interpreted by the spatial heterogeneity of the latter and the mixing of the paste with sandy temper. Fresh Adriatic sponge spicules in the majority of Laecanius sherds and the temper‐derived, generally immature heavy mineral assemblages suggest that sandy deposits from the Adriatic were used for the clastic temper. © 2006 Wiley Periodicals, Inc.     

The extension of the parametrization of the radio source coordinates in geodetic VLBI and its impact on the time series analysis

The radio sources within the most recent celestial reference frame (CRF) catalog ICRF2 are represented by a single, time-invariant coordinate pair. The datum sources were chosen mainly according to certain statistical properties of their position time series. Yet, such statistics are not applicable unconditionally, and also ambiguous. However, ignoring systematics in the source positions of the datum sources inevitably leads to a degradation of the quality of the frame and, therefore, also of the derived quantities such as the Earth orientation parameters. One possible approach to overcome these deficiencies is to extend the parametrization of the source positions, similarly to what is done for the station positions. We decided to use the multivariate adaptive regression splines algorithm to parametrize the source coordinates. It allows a great deal of automation, by combining recursive partitioning and spline fitting in an optimal way. The algorithm finds the ideal knot positions for the splines and, thus, the best number of polynomial pieces to fit the data autonomously. With that we can correct the ICRF2 a priori coordinates for our analysis and eliminate the systematics in the position estimates. This allows us to introduce also special handling sources into the datum definition, leading to on average 30 % more sources in the datum. We find that not only the CPO can be improved by more than 10 % due to the improved geometry, but also the station positions, especially in the early years of VLBI, can benefit greatly.     

Detecting the stepwise propagation of the Eastern Sicily thrust belt (Italy): insight from thermal and thermochronological constraints

An extensive dataset of vitrinite reflectance, FTIR parameters on organic matter, illite content in mixed layers illite‐smectite, apatite fission tracks and U‐Th/He dating has been used to reconstruct the stepwise propagation of the Eastern Sicily fold‐and‐thrust belt during Late Palaeogene and Neogene times. The results indicate that the fold‐and‐thrust belt is divisible into two levels of thermal maturity. These levels consist of a less evolved level of thermal maturity that records limited sedimentary burial and minor heating, and a more evolved level of thermal maturity that indicates tectonic burial and exhumation at different times. Deformation and exhumation of shallowly buried units are linked to wedge forward propagation by low‐angle thrusts, whereas the evolution of deeply buried units is associated with tectonic imbrications by duplex formation and steep thrusts. The two tectonic styles alternate during evolution of the fold‐and‐thrust belt under low erosion rates.     

Oxygen isotope composition and geothermometry of granulite to greenschist facies metamorphic rocks: a study from the Neoproterozoic collision-related nappe system, south of São Francisco Craton, SE Brazil

Oxygen isotope studies were carried out across units of a Neoproterozoic nappe system, south of São Francisco Craton. A temperature decrease toward the base of the system is found, consistent with a previously recognized inverted metamorphic pattern. The tectonic contact of the basal unit and the reworked southern São Francisco craton show a steep temperature gradient, suggesting that low temperature thrusting acted as the dominant tectonic process. The contrasts between the δ¹⁸O values of the Três Pontas-Varginha and Carmo da Cachoeira nappes and the differences among the samples and minerals are consistent with the preservation of sedimentary isotopic composition during metamorphism. The small differences in the δ¹⁸O values between the undeformed and the deformed calc-silicate samples (1.6‰) suggest that the δ¹⁸O value of mylonitization fluids was close to that which equilibrated with the metamorphic assemblage. The distinct δ¹⁸O values of metapelitic and calc-silicate samples and the great temperature difference from one type to the other indicate that no large-scale fluid interaction processes occurred during metamorphism. Oxygen isotopic estimations of both Três Pontas-Varginha undeformed rocks and Carmo da Cachoeira unaltered equivalents indicate δ¹⁸O values of up to 18‰. Comparison between these values and those from the ‘basement’ orthogneisses (8.3–8.5‰) indicates the latter are not sources for the metapelites.