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Zircon and monazite laser-ablation inductively coupled plasma mass spectrometry U–Pb geochronological data for two metasediment samples from the Westing Group, northern Shetland Islands, Scottish Caledonides yield ages between 938 ± 8 and 925 ± 10 Ma (Tonian) for upper amphibolites-facies metamorphism. Texturally early metamorphism is recorded by a migmatitic garnet + sillimanite + plagioclase + muscovite + biotite assemblage, which formed at c . 650–700 °C and 7 kbar. Subsequent reworking resulted in the growth of a secondary garnet + kyanite + plagioclase + muscovite + biotite assemblage at c . 650 °C and 8–9 kbar. In situ electron probe microanalysis (EPMA) U–Th–Pb chemical dating of monazite hosted within garnet grains and the matrix of one sample also give Tonian ages, apparently indicating that all the metamorphism occurred during the Neoproterozoic. However, the dominant structural fabrics appear to have formed during the Ordovician–Silurian Caledonian orogeny, suggesting that the reworking was substantially younger despite the apparent absence of Caledonian monazite or zircon ages. Detrital zircons are consistent with Laurentia–Baltica provenance. Deposition of the Westing Group is constrained to between c . 1030 and 930 Ma. The timing of Tonian metamorphism suggests possible correlations with sequences elsewhere in the northern Caledonides, including the Krummedal Succession of East Greenland and Laurentian-derived successions in Svalbard and northern Norway. Supplementary material: U–Pb LA-ICPMS and EPMA data are available at http://www.geolsoc.org/SUP18379 .

As an alternative to conventional Pb-containing solder material, Sn-Ag-Cu (SAC) based alloys are at the forefront despite limitations associated with relatively poor strength and coarsening of grains/intermetallic compounds (IMCs) during aging/reflow. Accordingly, this study examines the improvement of properties of SAC alloys by incorporating nanoparticles in it. Two different types of nanoparticles were added in monolithic SAC alloy: (1) Al 2 O 3 or (2) Fe and their effect on microstructure and thermal properties were investigated. Addition of Fe nanoparticles leads to the formation of FeSn 2 IMCs alongside Ag 3 Sn and Cu 6 Sn 5 from monolithic SAC alloy. Addition of Al 2 O 3 nano-particles do not contribute to phase formation, however, remains dispersed along primary β-Sn grain boundaries and act as a grain refiner. As the addition of either Fe or Al 2 O 3 nano-particles do not make any significant effect on thermal behavior, these reinforced nanocomposites are foreseen to provide better mechanical characteristics with respect to conventional monolithic SAC solder alloys.

X-Ray photoelectron spectroscopy can be applied to the study of the bonding of highly functionalised silicones on to E-glass fibres. The adsorption of six types of silicones (hydrido, epoxy, unsaturated imino, methacryl, 'terminal' amino and 'pendant' amino) from dilute toluene solutions were compared with that of a standard silane coupling agent. The calcium concentration was found to be an effective determinant of surface coverage by the siloxanes, as well as enabling the thicknesses of the adsorbed layers to be determined.

Traditionally LA-ICP-MS has been used to quantify trace element (wt%-ppb) concentrations in a wide variety of materials via spot analysis. This involves focussing a high energy pulsed UV Nd-YAG laser onto the region of interest on the surface of the sample, upon which the material is ablated. The ablated material is then transported into the argon plasma where it is broken down into constituent atoms and then ionised, whereupon it passes into the mass spectrometer and the elements of interest are analysed. In addition to spot analysis, the software allows rastering of the focussed laser beam in transects whereupon intensity and spatial distribution of elements can be recorded. Post acquisition processing then allows the transect data to be compiled into an image of elemental intensity.Existing instrumentation used to investigate trace element distribution in mineral and biological samples include EPMA, TEM, SEM, Ion Microprobe, Proton Microprobe, and synchrotron XRF analysis. All these techniques have their own benefits, but also their own inherent limitations whether they be high detection limits (>0.1 -1.0 wt%), very small analytical areas, complex sample preparation, and/or prohibitively expensive instrumentation. Imaging via LA-ICP-MS fits a niche in which its spatial resolution will never compare to electron beam techniques, however it has superior detection limits (ppb) over a wide elemental range (7Li to 238U), and can analyse a wide variety of materials with minimal sample preparation required. This study seeks to compare Laser Ablation and Electron Probe mapping. The different paradigm required for mapping using laser ablation ICPMS is discussed. It also demonstrates LAICPMS mapping of a range of samples, which experimentally are very difficult to analyse using traditional electron beam techniques.The ability to map trace elements and specific isotopes offers important information to researchers. Figure 1 following demonstrates different zoning characteristics in a garnet from a shear zone found when comparing major (1-3 wt %) and trace (ppb-ppm) elements found using both EPMA and LAICPMS mapping. These findings provide valuable information on elemental diffusion due to fluid movement in geological shear systems. 200566