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Silicic magma flare-up episodes are characterized by the addition of large volumes of evolved magma (>65 wt% SiO2) to the continental crust in geologically short time intervals (106-107 years). Flare-up events are often associated with (trans-)extensional tectonics and contribute to crustal differentiation and critical metal mineralization. Related volcanic aerosol dispersion in the atmosphere can also trigger global environmental changes. During flare-up episodes, long-lived caldera complexes are thought to be primary eruptive sources at the Earth’s surface. However, a substantial proportion of the overall mobile magma can be trapped in extra-caldera dikes, fissures and monogenetic edifices controlled by the extensional stress regime.In the Southern Alps of Northern Italy, a post-Variscan magmatic flare-up is recorded in a ca. 400 km long array of largely undeformed magmatic bodies of Early Permian age (285-275 Ma; [1]), then located along the northern margin of Gondwana. In the Southern Alps this flare-up produced more than 5*104 km3 of rhyolitic volcanic and cogenetic intrusive rocks. Two major caldera complexes (Sesia Caldera; Ora Caldera) were capable of ejecting volumes >103 km3 of magma during individual catastrophic eruptive events. However, magmatic activity also resulted in numerous scattered volcanic centers with relatively small eruptions (0.1 – 1 km3 each) and punctuated by quiescent intervals.In this study we focus on two Early Permian fault-bounded basins, ca. 40 km apart, in the central Southern Alps: the Orobic Basin (Bergamo) and the Collio Basin (Brescia). The stratigraphic records of both basins preserve proximal and distal volcanic products and both successions terminate with erosional unconformities of Middle- to Late Permian age. New zircon LA-ICP-MS U-Pb ages indicate that the onset of explosive, rhyolitic magmatism was essentially coeval at ~284 Ma. The Collio Basin contains just a few ignimbrite sheets dispersed in an essentially (fluvio)-lacustrine sedimentary fill and recording a pulsated volcanic activity of nearly 5 Myr (youngest ignimbrite ~280 Ma). After an initial phase (1-2 Myr) of a similar pulsed nature, the Orobic Basin became the locus of extrusion of much larger volumes of rhyolitic magma (probably in excess of 100 km3) in less than 1 Myr (283-282 Ma). This was followed by a depositional style similar to the Collio but with a scarcer pyroclastic contribution.The contrasting volcanic record in these two basins, which share size and tectonic environment but not magmatic evolution, provides a striking example of magmatic architecture diversity in the midst of a silicic flare-up event. Further investigation into the timing (CA-ID-TIMS U-Pb geochronology) and compositional evolution (e.g., zircon d18O, eHf) of volcanic products in the Collio and Orobic basins is expected to provide a much better resolved comparison and open a window into the combined tectono-magmatic processes that ultimately regulate the size and frequency of catastrophic, caldera-forming eruptions in silicic flare-up provinces.[1] Schaltegger, U., & Brack, P. (2007). International Journal of Earth Sciences, 96(6), 1131-1151.

Victoria was the Australian state most significantly affected by the COVID-19 pandemic in 2020, which caused significant disruption to Victorian health services. The aim of this case study is to describe the experience of the Victorian public health system in adapting to support allied health student education during the pandemic. Factors that affected student education were complex and dynamic, and included a decrease in traditional face-to-face learning opportunities due to a transition to telehealth, social distancing requirements, furlough of staff and travel restrictions. Impacts on placement capacity across allied health professions were highly variable. Strategies used to enable the continuation of student work-integrated learning (WIL) (also referred to as clinical placements or fieldwork) included an increase in remote placements and the use of technology. Enhanced communication between government and health service educators enabled rapid sharing of information and problem solving. At this time, the impacts on student preparedness for practice are unclear but may include deficits in interprofessional learning, clinical skills, increased levels of agility and enhanced resilience. This case study highlights the need for the health system to be adaptable and innovative to maintain the quality of student education, and the future allied health workforce, through the pandemic and beyond. What is known about the topic? The COVID-19 pandemic caused significant disruption to Victorian health services and consequently their ability to support WIL for students during this time. The pandemic created risks for continuity of student learning and future allied health workforce supply. What does this paper add? The challenges that Victorian public health services faced to support student education during the pandemic were complex and dynamic. This paper describes the ways in which health services adapted to optimise the capacity and quality of student education. What are the implications for practitioners? This case study highlights that a focus on student well-being and a high level of problem solving for health services were required to support student learning during the pandemic, and that enhanced communication between government and health services supported the rapid sharing of innovations. These strategies can be used to support quality student WIL through the pandemic and beyond.

Crustal-scale magmatic systems act as filters between the mantle and the atmosphere, and can generate large volcanic eruptions that pose significant hazards while altering Earth’s climate. Quantifying the growth rates, magma fluxes, and duration of storage at different crustal levels is crucial for understanding such systems, but these parameters are poorly constrained due to the scarcity of exposed crustal sections. Here we present the first detailed reconstruction of magma emplacement and differentiation time scales of a complete crustal-scale igneous system exposed in the southern Alps (Ivrea-Sesia region, northern Italy) to quantify the magma fluxes and duration of transcrustal magmatism. Integrated zircon U-Pb petrochronology and numerical modeling provides unprecedented evidence that the volcanic and plutonic bodies are directly related to each other both chemically and temporally, suggesting that the entire magmatic system grew rapidly from its deepest roots to the erupted products. In the entire crustal section, zircons record 4 m.y. of magma accretion, but the bulk of the magma was emplaced within approximately 2 m.y. during an episode of enhanced magma flux from the mantle. Our results show the synchronous growth and differentiation of discrete magma bodies at various crustal levels beneath silicic caldera volcanoes and reconcile modeling and geochronological results on crustal-scale heat and mass transfer.

The Adamello intrusive suite is a composite batholith in Northern Italy, with an estimated 2000 km3 volume, assembled incrementally over a time span of 10 to 12 million years. The history of crystallization has been studied in detail through laser ablation ICP-MS and SIMS U–Pb geochronology of zircon, which records prolonged crystallization of each of the different intrusive units at mid-crustal levels between 43·47 and 33·16 Ma. The magmas were episodically extracted from this storage area and ascended to the final intrusion level at ∼6 km paleo-depth. Each batch of melt cooled very rapidly down to the ambient temperature of 250°C, evidenced by distinct cooling paths recorded by amphibole, biotite and K-feldspar 40Ar/39Ar dates. The magma source area was moving from SW to NE with time, causing increasing thermal maturity in the mid-crustal reservoir. The resulting temporal trend of higher degrees of crustal assimiliation in the course of the evolution of the magmatic system can be traced through Hf and O isotopes in zircon. Rough estimates of magma emplacement rates (‘magma flux’) yield very low values in the range of 10-4 km3/yr, typical of mid-to-upper crustal plutons and increase with time. Although we cannot discern a decrease of magma flux from our own data, we anticipate that a dramatic decrease of magma flux between 33 and 31 Ma along the northern contact lead to cessation of magma emplacement. ISSN:0022-3530 ISSN:1460-2415

The species Chieseiceras dolomiticum n. sp. along with other ammonoid species (Latemarites latemarensis, Halilucites rusticus) helps constraining the age of the cyclic platform interior portion at Latemar (Dolomites, northern Italy). The comparison of ammonoids from the Latemar platform with the fossil record in basinal successions in the Southern Alps (including the Ladinian GSSP section at Bagolino) and Hungary suggests that the entire rhythmically bedded Latemar interval is entirely late Anisian in age. More than 400 stratigraphical metres of bedded shallow water carbonates at Latemar are found to correspond to less than 5 m of siliceous nodular limestone in the pelagic succession at Bagolino. The refined correlation will be significant for the reassessment of the cyclic Latemar stratigraphy in the light of new geochronological calibration of the South Alpine Middle Triassic.

Tracing the origin and evolution of magmas on their pathway through the lithosphere is key to understanding the magmatic processes that eventually produce eruptions. For ancient magmatic provinces, isotope-geochemical tracers are powerful tools to probe the source regions and magma-crust interaction during ascent and storage.We present new hafnium isotopic compositions of ID-TIMS dated zircons to trace the evolution of the Middle Triassic magmatic province in the Southern Alps (northern Italy) at high temporal resolution [1]. Systematic changes in hafnium isotopic composition with time reveal a coherent temporal evolution from depleted mantle signatures towards crust-dominated signatures within less than four million years. This trend can be ascribed to progressive influence of a crustal source, incorporated into the reservoir from which these zircons crystallized. Towards the end of the magmatic episode, the εHf compositions abruptly revert within one-million-years back towards more juvenile compositions mainly recorded by the mafic to intermediate intrusive pulses (e.g. Monzoni and Predazzo), the effusive climax of basaltic lavas and the post-intrusive ash beds (e.g. Punta Grohmann) in the Dolomite region. We interpret the variation of Hf-isotopic signatures over time as a protracted contamination signal induced by interaction of the mantle-derived magmas with the lower crust.The dataset obtained in this study is further implemented into a two-component mixing model employing a range of potential crust and mantle endmember Hf isotope signatures and Hf concentrations which is directly translated into crustal melt/total melt (=sum of crustal and mantle-derived melt) ratios over time. Based on these observations we explored the thermal evolution and crustal melting as a function of time, lithology, water content and magma flux for a lower crustal magmatic system by numerical modelling. Dykes and sills of basaltic composition are incrementally emplaced at the mantle-crust boundary, which leads to changes in crustal over mantle melt ratios over time. Initial intrusions of basaltic dykes into the relatively cold lower crust cause only limited crustal melting and assimilation but ensuing magma injections into progressively hotter crust results in more extensive partial melting and assimilation of crustal material. Subsequent intrusions into the magmatic lower-crustal roots cannibalize previous intrusions with progressively less isotopic contrast due to dilution with mantle-derived magmas. This is potentially accompanied by an increase in magma flux, e.g. by delamination of dense lower crustal cumulates into the subcontinental lithospheric mantle.The observed trends in hafnium isotopic composition therefore do not necessarily require tectonic re-organizations or changes in mantle sources. Instead these trends may trace variations in mantle-crust interaction during thermally induced chemical maturation of the lower crustal magmatic roots progressively replacing ancient pelitic to mafic lower crustal lithologies by juvenile cumulates. [1] Storck, J.-C., Wotzlaw, J.-F., Karakas, O., Brack, P., Gerdes, A., Ulmer, P. Hafnium isotopic record of mantle-crust interaction in an evolving continental magmatic system, Earth and Planetary Science Letters, (in press).

Tracing the origin and evolution of magmas on their pathway through the lithosphere is key to understanding the magmatic processes that eventually produce eruptions. For ancient magmatic provinces, isotope-geochemical tracers are powerful tools to probe the source regions and magma-crust interaction during ascent and storage. Here we present hafnium isotopic compositions of ID-TIMS dated zircons to trace the evolution of the Middle Triassic magmatic province in the Southern Alps (northern Italy) at high temporal resolution. Systematic changes in hafnium isotopic composition with time record progressively stronger crustal assimilation over 3.5 million years, followed by a rapid increase in eHf towards more juvenile compositions for the major pulse of mafic intrusions and post-intrusive volcanic ash beds within one million years. We interpret these trends to reflect variations in mantle-crust interaction through time. Initial intrusions of basaltic dykes into the relatively cold lower crust cause only limited crustal melting and assimilation but an ensuing magma injection into progressively hotter crust results in more extensive partial melting and assimilation of crustal material. Subsequent intrusions into the magmatic lower-crustal roots cannibalize previous intrusions with progressively less isotopic contrast due to dilution with mantle-derived magmas. This is potentially accompanied by an increase in magma flux due to delamination of dense lower crustal cumulates into the subcontinental lithospheric mantle. The observed trends in hafnium isotopic composition therefore do not necessarily require tectonic re-organizations or changes in mantle sources. Instead these trends may trace variations in mantle-crust interaction during thermally induced chemical maturation of the lower crustal magmatic roots progressively replacing ancient pelitic to mafic lower crustal lithologies by juvenile cumulates.

Interprofessional education is important to help prepare and develop a health professional workforce that practices collaboratively. The aim of this systematic review was to examine the benefits of participation in short duration clinically-based interprofessional activities for health care professional students. Eight electronic databases (MEDLINE, CINAHL, PUBMED, EMBASE, PsychINFO, PEDRO, ERIC, OT Seeker) were searched from inception to June 2017. Full-text English-language studies reporting outcomes of short duration clinically-based interprofessional activities involving health professional students from at least two disciplines were included. Studies were excluded if they evaluated longer duration, iterative or simulation-based interprofessional activities. Data were analysed descriptively and using content analysis based on the Core Competencies for Interprofessional Collaborative Practice framework. Of 521 identified articles, 13 were identified for inclusion and assessed for quality independently by two reviewers. The included studies assessed two types of interprofessional activities (shadowing and patient reviews) completed by a range of different student cohorts including those from medicine, pharmacy, nursing, dietetics, physiotherapy, occupational therapy, social work, podiatry, speech pathology, and medical imaging. Students perceived shadowing a health professional from another discipline, for between 2 and 10 hours during the early stages of their training, improved their understanding across all domains of the Core Competencies for Interprofessional Collaborative Practice framework. Students who completed patient review activities with at least one other student or staff member from another discipline, for 2.5 to 4 hours during the later stages of their training, described developing clinical skills in addition to improving their understanding of the roles and responsibilities and teamwork domains of the Core Competencies for Interprofessional Collaborative Practice framework. A low quality body ofevidence suggests short duration clinically-based interprofessional activities may help prepare health professional students to work collaboratively.

Orbitally forced cyclic variations in sedimentary sequences provide evidence for short-term fluctuations of Earth climate and a tool for high-resolution timescale calibration. We here present stratigraphic and geochronological evidence for precession-forcing in Middle Triassic hemipelagic limestones of the Buchenstein Formation (Dolomites, northern Italy). High-resolution stratigraphy of several correlative sections of the Buchenstein Formation documents a coherent cycle pattern. Isotope dilution thermal ionization mass spectrometry zircon U–Pb geochronology of tuffs bracketing the cyclic interval reveals an average cycle duration of 18.5 ± 2.1 kyr, consistent with a shorter climatic precession cycle in the Middle Triassic compared with today. This suggests a predominantly precession-controlled climate in this low-latitude setting of the western Tethys and allows high-precision calibration of the Anisian–Ladinian boundary interval. From integrating cyclostratigraphic and U–Pb geochronological constraints, our best estimate for the age of the Anisian–Ladinian boundary is 241.464 ± 0.064/0.097/0.28 Ma. We also provide precise estimates for lithostratigraphic boundaries, biostratigraphic markers and magnetic reversals within the boundary interval. Stratigraphic intervals with elevated sedimentation rate record a sub-Milankovitch signal that may be equivalent to patterns in adjacent carbonate platforms such as the Latemar platform. The origin of this sub-Milankovitch signal remains unknown but highlights the potential to investigate shorter-term climatic variations in Mesozoic sedimentary sequences. Supplementary material: Isotope dilution thermal ionization mass spectrometry U–Pb and laser ablation inductively coupled plasma mass spectrometry trace element data tables as well as the results of the Bayesian age modelling are available at https://doi.org/10.6084/m9.figshare.c.3861817.

Variations in the sulfur isotope composition of dissolved marine sulfate through time reflect changes in the global sulfur cycle and are intimately related to changes in the carbon and oxygen cycles. A large shift in the sulfur isotope composition of sulfate at the Permian/Triassic boundary has been recognized for long time and a number of studies were carried out to understand the causes and significance of this shift. However, data for the Middle and Late Triassic are very sparse and the stratigraphic evolution of the sulfur isotope composition of seawater is poorly constrained due to the small number of samples analyzed and/or due to the limited stratigraphic intervals studied. Moreover, in the last few years the Triassic timescale has significantly changed due to a wealth of new radiometric and stratigraphic data. In this study we show that for the Late Permian and the Triassic it is possible to obtain a precise reconstruction of the evolution of the sulfur cycle, for parts of it at sub-million year resolution, by analyzing exclusively gypsum and anhydrite deposits. We base our reconstruction on new data from the Middle and Late Triassic evaporites of Northern Switzerland and literature data from evaporites from Germany, Austria, Italy and the Middle East. We propose a revised correlation between the well-dated marine Tethyan sections in northern Italy and the evaporites from Northern Switzerland and from the Germanic Basin calibrated to the newest radiometric absolute age scale. This new correlation allows for a precise dating of the evaporites and constructing a composite sulfur isotope evolution of seawater sulfate from the latest Permian (Lopingian Epoch) to the Norian. We show that a rapid positive shift of approximately 24‰ at the Permian-Triassic boundary can be used to constrain seawater sulfate concentrations in the range of 2–6 mM, thus higher than previous estimates but with less rapid changes. Finally, we discuss two possible evolution scenarios for the Middle Triassic negative shift to values of 15‰ that subsequently remain constant during the Late Triassic.

Journal of the Geological Society, 176 (2), ISSN:0016-7649, ISSN:2041-479X

The Alpine Triassic units of Switzerland, Northern Italy and Western Austria offer an extensive geological archive, in which the enigmatic process of dolomite formation can be studied in a palaeoenvironmental context. Recent studies clearly demonstrate that large amounts of the Alpine Triassic dolomites are late diagenetic or hydrothermal. Nevertheless, as part of multiple generations of diagenetic overprint, some generations of fine-crystalline, Ca-rich dolomite appear strictly confined to their depositional facies and show signs of very early formation at surface temperatures in specific ancient depositional environments. In this review, three cases of Alpine Triassic dolomites are discussed, where dolomite rocks may have formed during or soon after sedimentation. The sedimentary facies indicate contrasting palaeoenvironmental conditions and, hence, document three different possible processes of dolomite formation: (i) In the Dolomite Mountains (Northern Italy), dolomite beds of the partly isolated Middle Triassic (Anisian/Ladinian) Latemar Platform are confined to the very top of shallowing-upward lagoonal facies cycles. (ii) Dolomite beds of the San Giorgio Basin (Southern Switzerland), an intra-platform basin that opened during the Anisian/Ladinian transition, are associated with organic carbon-rich shales, which were deposited in a deeper water environment under anoxic conditions. (iii) In the entirely dolomitized platform facies of the Dolomia Principale (Hauptdolomit Formation), a very early generation of fine-crystalline dolomite occurs in the shallowest part of evaporative peritidal cycles. This platform extended over thousands of square kilometres along the Tethys margin during the Late Triassic (Carnian and Norian) and large amounts of carbonate were deposited under hypersaline sabkha-like conditions. Representing three distinct depositional environments, these three different Triassic systems show features in common with several dolomitization models developed from the study of modern dolomite-forming environments; for example, the sabkha model, the evaporative lagoon/lake model, the organogenic model and the microbial model. Although these actualistic models may be applicable to reconstruct the palaeoenvironmental conditions during dolomite formation, dolomite-forming processes during the Triassic were apparently quite different from the modern world in terms of distribution and scale. Recent developments in stable-isotope geochemistry and high-resolution geochemical probing offer the possibility to make better reconstructions of Triassic palaeoceanographic conditions and suggest a non-actualistic approach to better understand dolomite formation during the Triassic.

Indentation of rigid blocks into rheologically weak orogens is generally associated with spatiotemporally variable vertical and lateral block extrusion. The European Eastern and Southern Alps are a prime example of microplate indentation, where most of the deformation was accommodated north of the crustal indenter within the Tauern Window. However, outside of this window only the broad late-stage exhumation pattern of the indented units as well as of the indenter itself is known. In this study we refine the exhumational pattern with new (U–Th–Sm)/He and fission-track thermochronology data on apatite from the Karawanken Mountains adjacent to the eastern Periadriatic fault and from the central-eastern Southern Alps. Apatite (U–Th–Sm)/He ages from the Karawanken Mountains range between 12 and 5 Ma and indicate an episode of fault-related exhumation leading to the formation of a positive flower structure and an associated peripheral foreland basin. In the Southern Alps, apatite (U–Th–Sm)/He and fission-track data combined with previous data also indicate a pulse of mainly Late Miocene exhumation, which was maximized along thrust systems, with highly differential amounts of displacement along individual structures. Our data contribute to mounting evidence for widespread Late Miocene tectonic activity, which followed a phase of major exhumation during strain localization in the Tauern Window. We attribute this exhumational phase and more distributed deformation during Adriatic indentation to a major change in boundary conditions operating on the orogen, likely due to a shift from a decoupled to a coupled system, possibly enhanced by a shift in convergence direction. Electronic supplementary material The online version of this article (doi:10.1007/s00531-016-1367-3) contains supplementary material, which is available to authorized users.

Geochemical, structural, field, and geochronological data have been used to arrive at very different models for the construction of upper crustal batholiths. Models for pulsed intrusion of small magma batches over long timescales (>1 Ma) versus transfer of larger magma bodies on shorter timescales predict a different thermal, metamorphic, and rheological state of the crust, highlighting the importance of robust time constraints. This study focuses on a well-characterized upper crustal intrusion, the 15 km2 Lago della Vacca complex (LVC), Adamello batholith, N. Italy. Previous studies used structural and petrologic data to argue that the LVC was emplaced through pulsed magma injection and in situ expansion (or, ballooning) of a short lived (∼ 105 yr) magma chamber. We test this model using a dense sampling strategy and high-precision ID-TIMS U-Pb geochronology of zircon and titanite combined with hafnium isotope and trace element analyses of the same volume of dated mineral (U-Pb TIMS-TEA). These data show that the marginal mafic pulses of magma crystallized zircon with primitive Hf isotopes and negligible Eu anomalies during fractional crystallization and ascent through the crust on 10-30 ka timescales. Subsequent, more felsic pulses yield individual zircon dates spanning as much as 200 ka within single handsamples and restrict the total construction time of the LVC to

A review of geochronological data underlying the geological time-scale for the Triassic yields a significantly different time-scale calibration than that published in the most recent compi- lation (Geologic Time Scale 2004). This is partly due to the availability of new radio -isotopic data, but mostly because strict selection criteria are applied and complications arising from biases (both systematic and random) are accounted for in this contribution. The ages for the base and the top of the Triassic are constrained by U- Pb ages to 252.3 and 201.5 Ma, respectively. These dates also constrain the ages of major extinction events at the Permian- Triassic and Triassic- Jurassic bound- aries, and are statistically indistinguishable from ages obtained for the Siberian Traps and volcanic products from the Central Atlantic Magmatic Province, respectively, suggesting a causal link. Ages for these continental volcanics, however, are mostly from the K -Ar ( 40 Ar/ 39 Ar) system, which requires accounting and correcting for a systematic bias of c. 1% between U -Pb and 40 Ar/ 39 Ar isotopic ages (the 40 Ar/ 39 Ar ages being younger). Robust age constraints also exist for the Induan- Olenekian boundary (251.2 Ma) and the Early- Middle Triassic (Olenekian-Anisian) boundary (247.2 Ma), resulting in a surprisingly short dur- ation of the Early Triassic, which has implications for the timing of biotic recovery and major changes in ocean chemistry during this time. Furthermore, the Anisian-Ladinian boundary is con- strained to 242.0 Ma by new U- Pb and 40 Ar/ 39 Ar ages. Radio- isotopic ages for the Late Triassic are scarce, and the only reliable and biostratigraphically-controlled age is from an upper Carnian tuff dated to 230.9 Ma, yielding a duration of more than 35 Ma for the Late Triassic. All of these ages are from U-Pb analyses applied to zircons with uncertainties at the permil level or better. The resulting compilation can only serve as a guideline and must be considered a snapshot, resolving some of the issues mainly associated with inaccurate and misinterpreted data in previous publi- cations. However, further advances will require revision of some of the data presented here.

A set of large strain deformation experiments is presented to better constrain the conditions in which grain size sensitive mechanisms are dominant during deformation of dolomite. Experiments were made on an internally heated gas apparatus equipped with torsion facilities. The rheological data set was fitted to an empirical flow law that allows extrapolation to natural conditions. Fabric evolution with increasing strain was investigated by means of optical and electron microscopy (electron backscattered diffraction). Extrapolation of the laboratory data to geologically relevant conditions of temperature and strain rate was tested on a natural case of a deformed dolomite–calcite sequence across the contact aureole of the Adamello pluton (southern Alps, Italy). Both the geological data and the laboratory measurements indicate that at high temperature an inversion of the relative strength occurs between the two carbonates, with calcite being the weak phase at low temperature and dolomite being the weak phase at high temperature.

Swiss Journal of Geosciences, 100 (3), ISSN:1661-8734, ISSN:1661-8726

In a recent contribution to this journal Preto et al. (2005) present stratigraphic results and correlations of sediments of the Middle Triassic Buchenstein basin (Buchenstein/Livinallongo Fm.) of the Southern Alps. The data are then used for quantifying the rates of pelagic sedimentation and for the interpretation of observed dissolution features. Because we feel that some relevant conclusions presented therein are either not supported by field evidence or have been proposed previously, with this discussion we intend to clarify some aspects of the geology of the hemipelagic Buchenstein basin. The aspects discussed here address the following points: 1) the reliability of the proposed stratigraphic correlations and the importance of the post-depositional diagenetic modification for assessing the variations in rates of sedimentation; 2) the origin and rates of sediment accumulation of the Plattenkalke versus the Knollenkalke; 3) aragonite dissolution versus compation-driven diagenesis and the bias of the fossil record. Graphical logs of the Buchenstein sediments along with stratigraphic and sedimentologic analysis demonstrate that the Buchenstein basin was fed from different sediment sources whose relative importance has changed through time and space (e.g., Ogilvie Gordon, 1927; Viel, 1979; Bosellini and Stefani, 1991; Brack and Rieber, 1993; Maurer and Schlager, 2003). Relevant for the assessment of basinal sedimentation rates proposed in Preto et al. (2005) are the new data presented for two basinal sections (Rio Sacuz, San Marco) along with information mainly adapted from the literature (Seceda, Bagolino).

Based on the palynological study of the Seceda core drilled in the north-western Dolomites and of an outcrop section from Val Gola–Margon (Southern Alps, Northern Italy) we propose a new palynostratigraphic subdivision of the Middle Triassic of the Western Tethyan realm. The six new zones (TrS-A–TrS-F) cover the interval between the late Anisian (Illyrian) and the late Ladinian (Longobardian). The zonation is based on the first and last appearances of individual taxa as well as on the quantitative distribution of major groups of sporomorphs. The presented palynological succession is directly correlated with the precise biostratigraphic, magnetostratigraphic and chronostratigraphic framework of the Seceda section, which represents the principal auxiliary global stratotype section and point (GSSP) section of the Ladinian stage. As an additional record we use the data of Van der Eem (1983) newly calibrated using the detailed lithostratigraphic scheme of the Seceda section and the GSSP section from Bagolino. The reassessment of the data from the late Anisian and the Ladinian of Van der Eem (1983) and Brugman (1986) shows earlier occurrences of some of the major pollen groups, and results in more precise correlations with other areas. The overlapping ranges of the palynological phases and subphases proposed by Van der Eem (1983) and Brugman (1986) make some of these phases obsolete. Within the studied interval the distribution of sporomorphs shows some major changes such as a major reduction of pteridosperms (e.g. taeniate bisaccate pollen), which are abundant in the lower part of the section (zone TrS-A) and are subsequently replaced by conifers (e.g. Triadispora , Ovalipollis and Circumpolles). Palynofacies studies show that the relatively high amount of fluorescent amorphous organic matter (AOM) reflects dysoxic conditions in the lowermost part of the section (“ Plattenkalke ”). The change in palynofacies between the “ Plattenkalke ” and the “ Knollenkalke ” corresponds to a marked change in the depositional environment from dysoxic to well oxygenated conditions in the “ Knollenkalke ”. In contrast to this, the succession of palynofacies from the “ Knollenkalke ” to the “ Breccias ” suggests a continuity of depositional environments reflecting a slight reduction of the oxic conditions. The light coloured pollen grains show no sign of thermal alteration of the organic matter.

Three different electron beam irradiated fluoropolymers (ETFE, FEP, and PVDF) as well as their grafting reactions with styrene in different diluents were investigated by means of electron spin resonance (ESR). Depending on the atmosphere during irradiation, ESR spectra of peroxy and alkyl radicals were observed. Radical decay as a function of time and temperature was investigated in the presence and absence of solvent. Grafting levels and number of monomer units per chain were calculated for both types of radicals. Irradiation atmosphere, grafting temperature, and added solvent affect the morphology of the fluoropolymers, in particular the crystalline versus amorphous fractions and their swelling. They thus influence the rate at which the initial radicals at the polymer backbone are reached during the grafting process. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3323–3336, 2006

New magnetostratigraphic data for the ~470-m-thick Latemar carbonate platform, which includes ~600 shallowing-upward bedding cycles, are consistent with litho- and biostratigraphic correlations of the section to a ~10-m-thick interval in the basinal Buchenstein Beds that most likely represents only ~1 m.y. of deposition according to published U–Pb single-crystal zircon dates. A reappraisal of reported cycle stratigraphic analyses of the Latemar suggests that the visibly obvious meter-scale bedding is not due to Milankovitch precessional forcing but rather reflects tempos an order of magnitude faster that may involve millennial-scale tidal amplitude variations. D 2004 Elsevier B.V. All rights reserved.

Membrane electrode assemblies (MEAs) based on radiation-grafted proton exchange membranes developed at PSI have shown encouraging performance in the past in hydrogen and methanol fuelled polymer electrolyte fuel cells. In this study, the effect of the pre-treatment of crosslinked radiation-grafted FEP membranes prior to lamination with the electrodes on the performance of the MEAs was investigated. Two approaches were assessed separately and in combination: (1) the impregnation of the radiation-grafted membranes with solubilised Nafion®, and (2) the use of a swollen vs. dry membrane. It is found that the combination of coating the membrane with Nafion® ionomer and hot-pressing the MEA with the membrane in the wet state produce the best single cell performance. In the second part of the study, the durability of an MEA, based on a radiation-grafted FEP membrane, was investigated. The performance was stable for 4,000 h at a cell temperature of 80 °C. Then, a notable degradation of the membrane, as well as the electrode material, started to occur as a consequence of either controlled or uncontrolled start-stop cycles of the cell. It is assumed that particular conditions, to which the cell is subjected during such an event, strongly accelerate materials degradation, which leads to the premature failure of the MEA.

The influence of irradiation and grafting on the crystallinity of three base polymers has been investigated with differential scanning calorimetry. Grafting has the largest effect on the base polymer crystallinity and results in a reduction of the crystallinity. The thermal degradation of the base polymers and grafted films has been investigated with thermogravimetric analysis. The extent of the fluorination of the base polymer, the irradiation method, and the graft level all influence the thermal degradation and its activation energy. It is proposed that the variation of the chain lengths of the grafted polystyrene chains is actually a primary underlying factor responsible for the influence of these various parameters on the degradation process. The first results of a comparative thermal analysis of some fuel-cell membranes are also presented, and the promise and shortcomings of this method are discussed.

The Middle Triassic carbonate buildups of the Dolomites show facies similarities with mud mounds but display apparent architectural elements of flat-topped carbonate platforms. In order to test whether the facies similarities to mounds are also reflected in the internal buildup architecture, a three-dimensional modelling study of the Middle Triassic Monte Cernera buildup has been carried out. The Cernera buildup exhibits apparent geometries suggesting a mounded platform in the lower and uppermost part of the buildup, separated by an interval with apparent platform geometry and a retrogradational platform interior, which is difficult to explain with a flat top platform model. For this purpose, a number of three-dimensional models were constructed using the three-dimensional modelling programme petrelTM. Key geological horizons were constructed based on outcrop measurements, intermediate horizons were calculated in the modelling program, and the intersections of the modelled layers with a digital topography surface were displayed and compared with outcrop photographs. The models were refined stepwise until a best fit with the actual bedding architecture was achieved. The best fit model shows that the mounded geometries in the lower and uppermost part of the buildup are real architectural elements. The intermediate platform stage, about 1·5 km across, had probably retained a mounded top with a relief of up to 50 m, which is difficult to distinguish from an absolutely flat top, but necessary to explain the retrogradational platform interior. The present study shows that Monte Cernera was dominated by mounded geometries at all stages of platform development. The mounded geometry plus facies data suggest that the platform is a deep-water accumulation, below the zone of intense wave energy, but within the photic zone. The Cernera represents a tropical buildup type, which did not have the capacity to grow into continuously wave-swept environments because of the small size and the absence of a wave-resistant energy barrier. Such buildup types are probably common after major crises in earth history, when reef organisms were virtually absent.

The pre-drift Wegenerian model of Pangea is almost universally accepted, but debate exists on its pre-Jurassic configuration since TedIrving introd ucedPangea ‘B’ by placing Gond wana farther to the east by V3000 km with respect to Laurasia on the basis of paleomagnetic data. New paleomagnetic data from radiometrically dated Early Permian volcanic rocks from parts of Adria that are tectonically coherent with Africa (Gondwana), integrated with published coeval data from Gondwana and Laurasia, again only from igneous rocks, fully support a Pangea ‘B’ configuration in the Early Permian. The use of paleomagnetic data strictly from igneous rocks excludes artifacts from sedimentary inclination error as a contributing explanation for Pangea ‘B’. The ultimate option to reject Pangea ‘B’ is to abandon the geocentric axial dipole hypothesis by introducing a significant non-dipole (zonal octupole) component in the Late Paleozoic time-averaged geomagnetic field. We demonstrate, however, by using a dataset consisting entirely of paleomagnetic directions with low inclinations from sampling sites confined to one hemisphere from Gondwana as well as Laurasia that the effects of a zonal octupole field contribution would not explain away the paleomagnetic evidence for Pangea ‘B’ in the Early Permian. We therefore regard the paleomagnetic evidence for an Early Permian Pangea ‘B’ as robust. The transformation from Pangea ‘B’ to Pangea ‘A’ took place during the Permian because Late Permian paleomagnetic data allow a Pangea ‘A’ configuration. We therefore review geological evidence from the literature in support of an intra-Pangea dextral megashear system. The transformation occurred after the cooling of the Variscan mega-suture andlasted V20 Myr. In this interval, the Neotethys Ocean opened between India/Arabia and the Cimmerian microcontinents in the east, while widespread lithospheric wrenching and magmatism took place in the west around the Adriatic promontory. The general distribution of plate boundaries and resulting driving forces are qualitatively consistent with a right-lateral shear couple between Gondwana and Laurasia during the Permian. Transcurrent plate boundaries associated with the Pangea transformation reactivated Variscan shear zones andwere subsequently exploitedby the opening of western Neotethyan seaways in the Jurassic.

Sedimentary cycles recorded in young sediments are often attributed to fluctuations of the Earth’s climate on a 10 4 )10 6 year scale which in turn is governed by periodic variations in solar insolation linked to orbital (Milankovitch) parameters. A spectacular example of cyclic stratal patterns in ancient deposits is the Middle Triassic Latemar carbonate platform (W Dolomites, N Italy). Based on spectral analyses from previous studies, a superimposition of precession (� 20 ka) and eccentricity (� 100 ka) controlled sea-level fluctuations has been suggested to account for the stacking hierarchy at Latemar, with � 20 ka being assigned to each highest-order depositional cycle. Zircon U‐Pb isotopic ages from volcanic-ash layers within the cyclic succession, corroborated by biostratigraphic constraints, suggest that the average time interval for every individual cycle is significantly smaller than the shortest Milankovitch period and therefore challenge previously published interpretations relating distinct spectral peaks to the above mentioned hierarchy. However, our new spectral data indicate that cyclicities resembling Milankovitch characteristics might exist, but on an entirely different scale. Our findings show that frequency spectra should only be interpreted in combination with robust age control. They also encourage the search for complementary mechanisms controlling carbonate deposition.

The crosslinking of functionalized polystyrene resins is often of critical importance in determining resin properties and performance in the application of these materials as membranes and supports. In this investigation model systems are developed for quantifying the infrared and Raman spectroscopic properties of copolymers based on poly(styrene-co-divinylbenzene). Analytical curves appropriate for the quantification of para- and metasubstituted species and pendant double bonds are reported, and corrections to previously reported spectroscopic assignments and analytical methods are made. The usefulness of these two analytical methods in characterizing radiation-grafted films and commercial copolymers is compared, and typical characterization results are given. The relative concentrations of the species found in the grafted films are quite different from their concentrations in the grafting solution, and empirical relationships between the two are developed. In addition, the graft composition varies as a function of the base polymer film thickness and type and the penetration depth in the grafted film. Radiation-grafted films are more highly crosslinked in their near surface regions, and thinner films are more extensively crosslinked.

New magnetostratigraphic and lithostratigraphic data are reported from the Pedraces and Belvedere limestone sections from the Dolomites region of northern Italy. These sections are comprised of the Buchenstein Beds of Late Anisian to Ladinian (Middle Triassic) age. The results from Pedraces and Belvedere are compared with data from the biostratigraphically and isotopically constrained Frotschbach and Seceda sections from the literature. A satisfactory magnetostratigraphic correlation is obtained on laterally traceable limestone and volcaniclastic intervals. These marker beds are then used to extend lithostratigraphic correlations to additional key sections from a palaeogeographically coherent area of around 500 km2. The aim of this study is to unravel the spatial and temporal evolution of the Buchenstein basin and the surrounding carbonate platforms. Platforms in the northwestern Dolomites show an early stage of aggradation followed by progradation, whereas in the central Dolomites the Cernera platform, after fast initial aggradation, drowned and became a pelagic seamount. In the intervening Buchenstein basin, the diVerential subsidence between the northwestern and central Dolomites is manifested by the lateral increase of thickness of ''Lower Pietra Verde'' volcaniclastic sediments. Accumulation of volcaniclastic material reworked from adjacent carbonate platform slopes characterised the more subsiding and unstable central Dolomites. In the pelagic carbonate intervals, the persistence over tens of kilometres of bedding patterns suggests that carbonate material presumably washed out from the surrounding, still active carbonate platforms was volumetrically small and homogeneously distributed throughout the uniformly subsiding Buchenstein basin. A Milankovitch precessional origin for the platform interior cycles at Latemar as suggested elsewhere implies a net accumulation rate of 2 m/Ma or less for the correlative interval of pelagic Buchenstein Beds. This value diVers significantly from the average value of around 10 m/Ma as calculated using high-resolution isotopic age data for the Buchenstein Beds. © 2000 Elsevier Science B.V. All rights reserved.

Proton-conducting polymer membranes are utilized as the solid electrolyte in low temperature polymer electrolyte fuel cells (PEFC), which are efficient energy converters. We have selected the process of radiation grafting and subsequent sulfonation to prepare novel membranes because of its feasibility as a low cost production method. Investigations of the two first preparations steps, i.e., irradiation and grafting, lead to insight concerning the optimization of these two steps and the dependence of the final membrane properties on the various preparation parameters.

Magnetostratigrapic and biostratigraphic data across the Anisian/Ladinian (Middle Triassic) boundary were obtained from the Frotschbach/Seceda section from the Dolomites region of northern Italy, and the Vlichos section from the Greek island of Hydra, where the Aghia Triada published section was also resampled. The Frotschbach/Seceda section includes two radiometrically dated (U Pb) tuff levels and covers two of the three chief candidates for the position of the base of the Ladinian, namely at the base of the Secedensis Zone or the subsequent Curionii Zone. The Aghia Triada section yields biochronological evidence for the base of the Secedensis Zone, whose significance is, however, critically discussed in the light of the magnetostratigraphic correlation with Frotschbach/Seceda. The Vlichos section can be correlated with Aghia Triada and Frotschbach/Seceda by means of magnetic polarity stratigraphy and sparse fossil occurrences. The satisfactory correlation of the magnetozones allows us to construct a composite geomagnetic polarity sequence tied to Tethyan ammonoid and conodont biostratigraphy for about a 2.4 Myr interval across the Anisian/Ladinian boundary.

The dielectric properties of selected ion-containing polymers have been studied by specular reflectance spectroscopy through the mid- and far-infrared regions. These reflectance spectra and the resulting dielectric spectra were measured on (1) surface-oxidized and cation-exchanged polyethylene and bulk ionomers based on (2) ethylene-co-methacrylic acid copolymers, and (3) partially para-sulfonated polystyrene. The chemical nature of the near surface region and its response to applied fields was studied for these materials. The far-infrared spectra were studied to examine the interaction of metal cations with anionic sites, and the polarizability in the far-infrared was found to vary systematically with the identity of the cation. Adhesion forces resulting from dispersion interactions due to polarization mechanisms at mid- and far-infrared frequencies were calculated by Lifshitz theory for polymer–Pyrex glass substrate pairs.

We report high-resolution single-zircon UPb age data for Middle Triassic volcaniclastic intercalations in biostratigraphically calibrated pelagic successions of the Southern Alps. The results require a redefinition of the chronometric scale for the Middle Triassic. Moreover, they do not support current models relating cyclic sedimentation in platform carbonates of the Dolomites to orbital tuning. Tight concordant age clusters were obtained for five volcaniclastic layers in three ammonoid biozones of late Anisian to early Ladinian age. Two layers in the (Nevadites) Secedensis Zone yielded identical mean 206 Pb 238 U ages of 241.2 + 0.8/−0.8 Ma and 241.2 + 0.8/−0.6 Ma (errors given at the 95% confidence level). A layer in the Gredleri Zone is dated at 238.8 + 0.5/−0.2 Ma, and two horizons in the Archelaus Zone yield similar ages of 237.9 + 1.0/−0.7 Ma and 238.0 + 0.4/−0.7 Ma. These results are significantly older than the age values of 233–235 Ma assigned to the Anisian/Ladinian boundary by several current time scales [1–4]. Moreover, our estimate of 240.7–241.3 Ma (depending on biostratigraphic collocation) for the Anisian/Ladinian boundary casts doubts on the reliability of age values of 245–250 Ma proposed by most time scales for the Permian/Triassic boundary. The occurrence of pelagic fossils in basinal sediments as well as in age-equivalent shallow marine Middle Triassic platform carbonates in the Dolomites allows the sedimentary sequences of both environments to be correlated. The 800 m thick Latemar platform (western Dolomites) is characterized by cyclic stacking patterns, which have been interpreted as results of Milankovitch-type high-frequency/low-amplitude sea-level fluctuations. The 12 m.y. interval of platform growth postulated from the assignment of orbital periodicities to the platform carbonate cycles [5,6] is in conflict with a maximum time span of 4.7 m.y. allowed by the present zircon data.

Three methods of estimating H20 contents of geologic glasses are compared: (1) ion microprobe analysis (secondary ion mass spectrometry), (2) Fourier-transform infrared spectroscopy(FTIR), and (3) electron microprobe analysis using the Na decay-curve method. Each analytical method has its own advantages under certain conditions, depending on the relative importance of analytical accuracy, precision, sensitivity, spatial resolution, and convenience, and each is capable of providing reasonably accurate estimates of the H20, or total volatile, content of geologicglasses.The accuracy of ion microprobe analyses depends critically on the availability of well-characterized hydrous standard glasses. Precision is often better than 0,2 wt% (10). The method provides good spatial resolution (-15 #m) and the capability to determine simultaneously the abundance of other volatile species of interest (e.g., F, B). FTIR spectroscopy provides excellent analytical sensitivity (-10 ppm), accuracy and precision «0.1 wt%),and the capability to determine the abundance of H20 and C02 species (H20, OH-, C02' eOj-) in analyzed glasses, although the spatial resolution (> 25-35 #m) is not as good as that of the ion microprobe. The main advantages of the estimation of H20 contents of hydrous glasses using the electron microprobe are excellent spatial resolution (- 10 #m) and analytical convenience. The disadvantages are that accuracy and precision (>0.5 wt%) are not as good as those associated with the other methods, but, for certain applications, these uncertainties may be acceptable for the estimation of H20 contents of H20-rich (> 1 wt%) samples.

Blends of polyamide-6 with lithium ionomers of 9.8 and 5.4 mole percent sulfonated polystyrene, formed by combining solutions of these polymers, are miscible over a wide compositional range, but those with the equivalent sodium ionomers are not. The molecular origin of this difference is addressed by studying the far infared and infrared spectra of the blends and pure materials to follow changes in the interactions between the cations and their surroundings, and changes in the interactions between functional groups. Based on analysis of these spectra, a molecular level interpretation of the blending is proposed. The initial step involves both the interaction of one amide carbonyl with an Li + ion and simultaneous hydrogen bonding between an amide N-H and a sulfonate group. This eventually leads to formation of an Li(>CO) n + (n∼4) entity while the sulfonates are converted to the acid form through hydrogen bonding to the amide N-H groups. The Na + ion does not interact strongly enough with the amide groups to leave its sulfonate environment to a significant extent

The dielectric properties of several types of ionic oxide glasses, sodium trisilicate and a series of lithium fluoroborate glasses, have been measured in the infrared and far infrared by reflectance methods and analyzed together with those reported earlier which were obtained in the 1 × 10 2 to 2 × 10 9 Hz region at temperatures from 25 to 300 °C by bridge and time domain reflectance (TDR) techniques, Together, these provide nearly continuous data from low frequency through 1.35 × 10 4 Hz, with a gap from about 2 × 10 9 to 7.5 × 10 11 Hz. Interpolation through this range has been addressed by consideration of the behavior of ϵ′(ω) at the limits of the measured ranges. It has been found that the damped harmonic oscillator-modelled ϵ″ (ω) features in the infrared and far infrared lead to ϵ′(ω) curves which extrapolate to those ϵ′(ω) curves measured at lower frequency and provide the interpolation and effectively continuous spectra from low frequency through the infrared.

This study documents ammonoids with a precise stratigraphic control at the middle/late Anisian (Pelsonian/Illyrian) boundary from a new locality in eastern Lombardy-Giudicarie (Monte Guglielmo) and from classical sections in Giudicarie. These ammonoid faunas allow revising the taxonomic interpretation of Ceratites cimeganus Mojsisovics 1882 and of the genus Paraceratites Hyatt 1900. Ceratites cimeganus is here assigned to the North American genus Rieppelites Monnet & Bucher 2005. In eastern Lombardy-Giudicarie, R. cimeganus is diagnostic of a distinct biochronological unit (cimeganus Zone) bracketed between the older Bulogites zoldianus Zone and the younger Judicarites euryomphalus–Paraceratites trinodosus zones. The recognition of this cimeganus Zone significantly improves worldwide correlation since it is recognized in several other Tethyan basins (Dolomites, Northern Calcareous Alps) as well as in North America (Nevada). These new data allow a redefinition of the middle/late Anisian boundary in the western Tethys, which is here intercalated between the zoldianus and cimeganus zones. This limit is marked by a clear ammonoid turnover (e.g. disappearance of Acrochordiceras and Balatonites, appearance of Rieppelites). Finally, the presence of sections including the cimeganus Zone in eastern Lombardy-Giudicarie allow the establishment of local gaps in sedimentation, which may reflect the regional and important transgression of the pelagic Prezzo Limestone over the shallow water platform carbonates of a “Camorelli-Dosso dei Morti barrier”, as also underlined by the spatial distribution of brachiopod lumachellas.

Swiss Journal of Geosciences, 100 (3), ISSN:1661-8734, ISSN:1661-8726

International Journal of Earth Sciences, 96 (6), ISSN:1437-3254, ISSN:1437-3262

In this work a simple novel method for preparing micro- and nanoscale patterns of polymer chains grafted onto flexible polymer substrates is described. A combination of the two techniques of radiation grafting and “grafting-from” has been made. This combination makes it possible to prepare grafted structures having micro- or nanoscale lateral dimensions that are determined by the electron beam or X-ray irradiation patterns used. The height of the grafted features can be controlled by the irradiation dose or such grafting reaction conditions as time, temperature, or monomer concentration. Our first results for nanopatterned samples demonstrate resolution comparable to those of other polymer-based lithography processes.

a Dipartimento di Scienze della Terra, Universita' di Milano, via Mangiagalli 34, 20133 Milan, Italy b Lamont-Doherty Earth Observatory, Palisades, NY 10964, USA c Department of Geological Sciences, Rutgers University, Piscataway, NJ 08854, USA d Dipartimento di Scienze Geologiche e Geotecnologie, Universita' di Milano-Bicocca, Piazza della Scienza 4, 20126 Milan, Italy e Departement Erdwissenschaften, ETH-Zentrum, CH-8092 Zu«rich, Switzerland f Department of Earth Sciences, Aarhus University, Aarhus, Denmark

Selective exposure of polymer substrates to extreme ultraviolet (EUV) radiation followed by graft polymerization of a second polymer is used to create patterns of polymer brushes. A key feature of this additive structuring process is the possibility to combine the properties of a polymer substrate in precisely predefined regions with the properties of the grafted material. Styrene brushes were grafted onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) substrates after exposure to synchrotron EUV radiation in an interference lithographic setup. The grafted chains are covalently bound to the surface, which allows physical or chemical post-processing without deterioration of the grafted structures.