The older ultramafic rocks of Aberdeenshire, similarities to SSZ ophiolites and significance for regional tectonics [abstract]

It has long been known that there are at least two phases of mafic-ultramafic magmatism in NE Scotland (Read 1919), the well known Younger Gabbro suite and a lesser known ‘Older suite’. A regional study of the ultramafic rocks (Styles 1994, 1999) showed that they comprised three groups, the Lower Zone of the Newer Gabbros and two closely related ones; a harzburgite group and a group of clinopyroxene-rich rocks referred to as the Succoth-Brown hill type (SBH) that were broadly the same as Reeds’ Older suite. The latter two groups are found along major regional scale shear zones, particularly the Portsoy Lineament. It was suggested that SBH type was the root complex of a volcanic arc (Gunn et al 1996) and that the harzburgite type were fragments of upper mantle (Styles 1999). Mapping of the UAE-Oman ophiolite by BGS (Styles 2006) showed that it consisted of an early mid ocean ridge phase followed by an extensive second phase of hydrous magmatism formed in a supra subduction zone (SSZ) setting that probably formed a proto volcanic arc prior to obduction. It will be shown that the ultramafic rocks of the mantle transition zone formed in this SSZ phase, dunites, olivine-clinopyroxenites, wehrlites and clinopyroxenites are essential the same as those in the SBH type in terms of both rock type and mineral composition. This provides strong supporting evidence that the older suite of ultramafic rocks are remnants of upper mantle and mantle transition zone of SSZ ophiolites and the shear zones where they are found delineate ‘sutures’ within the Dalradian basin. The ‘Newer gabbro’ intrusions are also closely associated with these regional shear zones, which suggests that these zones formed conduits for the extensive later magmatism

Platinum-group element mineralisation in the Unst ophiolite, Shetland

The ophiolitic basic and ultrabasic rocks of the island of Unst, Shetland comprise a sequence of harzburgites, dunites, clinopyroxene-rich cumulates, and gabbro, within tectonic blocks that have been thrust over a migmatite complex during the Laxer Palaeozoic. Concentrations of chromite are found in the harzburgite and dunite, and to a small extent in the pyroxene cumulate rocks. They occur as disseminations, sometimes forming millimetre scale layers, and as more massive schlieren and pods of chromitite. Five alteration or hydrothermal events have been recognised in the ultrabasic rocks. These comprise early pervasive serpentinisation, later fracture controlled serpentinisation, veining and pervasive carbonation, minor late serpentine veining and talc-carbonate alteration controlled by fault zones. Exploration for platinum group element (PGE) mineralisation uas carried out using a combination of drainage, overburden and rock sampling. Analyses of PGE were obtained by fire assay followed by either neutron activation analysis or flameless atomic absorption spectrometry, and up to 20 other elements Here determined by X-ray fluoresence analysis. Panned concentrate samples were taken from 73 drainage sites distributed throughout the complex. Ir, the only PGE determined in all samples, showed a greater concentration in samples derived from the harzburgite unit than those from other units. Lox amplitude anomalies are present in three discrete areas in the harzburgite but the maximum level of 210 ppb Ir is associated with a sample derived from a prominent N-S zone of faulting and hydrothermal activity markedly discordant to the regional trend of layering in the harzburgite and dunite. This discordant zone, which extends for at least 7 km, is also marked by samples containing enrichments in Fe, Co, Ni, Cu and As. The highest Cr levels are associated with an area in the north of the harzburgite with no previous history of chromite working but where many locally derived pieces of chromitite float have been discovered. Relatively high Cr levels are also associated nith the area of dunite containing the greatest concentration of visible chromite and old norkings. A technique of collecting panned heavy mineral concentrates from overburden samples was adopted as a reconnaissance exploration technique after orientation sampling in the harzburgite unit at Cliff, an area with high PGE levels in chromitite and associated dunite. Systematic sampling in the Cliff area outlined a zone of coincident Pd, Pt and Rh enrichment near to but separate from the chromite workings knorrn to be enriched in PGE. In contrast the distribution of Ru was entirely different with scattered lon amplitude anomalous zones and a maximum anomaly 300m from the chromite-rich zone. Reconnaissance lines were sampled at other locations within the harzburgite, dunite and cumulate units. Lore amplitude Pd and Pt anomalies were detected xithin the dunite unit, especially in 'a traverse across the trace of the prominent N-S fault zone at Helliers Uater, adjacent to the outcrop of the cumulate unit. In general the overburden data suggest some association between PGE enrichment and enhanced levels of Ni relative to typical silicate levels apparent when expressed as the ratio Ni/MgC. Rock samples Here collected from all parts of the complex, including most of the main chromitite workings. Very high levels of all PGE occur in samples of chromitite, chromite-rich dunite and dunite from the Cliff area, with a strong positive intercorrelation between all PGE. The proportions of the various PGE are very similar to those present in deposits in major layered basic/ultrabasic complexes like Bushveld and Stillwater, irith strong relative enrichment in Pd and Pt. These PGE proportions are completely different from the Ru-Ir-0s dominant assemblage typical of ophiolitic rocks. Associated with high levels of PGE are enrichments in Ni, Cu, As, Sb and Te. There is no correlation rrith Cr and some samples of chromitite from the Cliff area contain only background levels of PGE. High to moderate levels of PGE with the same proportions of elements as the Cliff samples also occur in samples of chromitite and serpentinised dunite from the dunite unit and in samples of pyroxenite from the cumulate unit, In contrast PGE-rich samples of chromitite from the harzburgite unit near Harold's Grave have entirely different proportions of PGE with Ru and Ir in greatest abundance. This PGE distribution is similar to that in some background samples of harzburgite and closely resembles the pattern found in typical ophiolites. The PGE in the Harold's Grave samples do not exhibit the Ni enhancement noted in the Cliff PGE mineralisation. In samples from the Cliff area the platinum-group minerals (PGM) sperrylite, stibiopalladinite, hollingnorthite, laurite and possibly irarsite have been identified, mostly as grains less than 10 microns in size. In chromite-rich rocks these minerals occur Rithin chlorite haloes around chromite, in the blackened altered rims of chromite grains and in interstitial Ni-rich serpentine/carbonate intergroxths in association with pentlandite, orcellite and other Ni sulphides and arsenides, sometimes spatially related to chlorite-carbonate-magnetite veins. They also occur as fine grains Rithin magnetite rims around chromite and in magnetite or carbonate veins in dunite. The Ni sulphide/arsenide assemblage associated Rith the PGH is characteristic of serpentinisation at temperatures less than 500'C, Rell belox the range of magmatic conditions. A hydrothermal origin for the PGE mineralisation is proposed, probably related to the second phase of serpentinisation. This involved the redistribution of Ni accompanied by the introduction of As, Sb and Te probably with a StrUCtUral Control. Pre-existing concentrations of chromite may have acted as a precipitation barrier causing rich PGH deposition in the alteration haloes around chromite grains. Continuous borehole or trench sections through mineralised zones are required to assess the economic significance of the PGE mineralisation. Nevertheless the high levels of PGE attained and the evidence of xidespread occurrence of the Cliff-type PGE enrichment are favourable indications. The PGE enrichments found in the cumulate complex are of potential interest as they may originally have been of magmatic origin. Larger tonnage targets may therefore be present in this unit compared Rith the likely size of structurally-controlled mineralisation elswhere in the complex

Monitoring and Modelling the Vibrational Effects of Small (<50 kW) Wind Turbines on the Eskdalemuir IMS Station

It is known (Styles et al., 2005) that windfarms generate low frequency vibrations which propagate through the ground and have the potential to adversely affect sensitive installations, most notably seismometer arrays set up to monitor for nuclear tests. Significant work on the effects of large wind turbines has been carried out by Keele University as well as by Schofield (2002) and Fiori et al (2009). For the Eskdalemuir International Monitoring System station in Scotland, a vibration threshold was set, for wind farms within 50 km of Eskdalemuir, at frequencies around the 4 to 5 Hz region. However, with increased development, the threshold is being approached and small wind turbines (less than 50kW), even of the order of 15kW have also been restricted despite the differences in scale and modes of vibration. In order to protect Eskdalemuir a threshold limit was set for any turbine as a holding measure and a programme to try to establish whether they were really problematic has been carried out. Models for two wind turbine types from the manufacturers Proven and Gaia-Wind have been calculated and measurement programmes carried out. It has been possible to demonstrate that in most cases these small turbines do not generate significant energy in the band of concern and that the levels are low enough to be negligible. Small turbines once evaluated and monitored by Keele University and given approval by the UK Ministry of Defence, will receive clearance for deployment around the Eskdalemuir site at distances greater than 10km

Analysis and computations for a model of quasi-static deformation of a thinning sheet arising in superplastic forming

We consider a mathematical model for the quasi-static deformation of a thinning sheet. The model couples a first-order equation for the thickness of the sheet to a prescribed curvature equation for the displacement of the sheet. We prove a local in time existence and uniqueness theorem for this system when the sheet can be written as a graph. A contact problem is formulated for a sheet constrained to be above a mould. Finally we present some computational results

Seismic Expressions of Thermochemical Mantle Plumes

Over the last decade of geophysical research the concepts of hotspots and plumes have taken a central role in discussions of the interior structure of the Earth and global geodynamic plate and convection models. In this study, I focus on the ability of thermal and/or thermochemical plumes to reproduce global and regional seismic observations at hotspot locations on Earth. In order to make meaningful interpretations of seismic images from global tomographic images I begin with an investigation into the physical meaning of seismic reference models and a full exploration of the temperature and compositional sensitivities of mantle seismic velocities, utilising a fully consistent forward modelling approach with up-to-date mineral physics parameters and associated uncertainties. I determine that, despite three-dimensional complexity of the mantle, averaged seismic structure reflects the average radial physical structure of the mantle except near phase boundaries and within thermal boundary layers. In the second half of the study I produce synthetic plume signatures by converting the thermo-chemical strutures of a range of plausible dynamic whole mantle plumes into seismic velocities-including the effect of seismic resolution in global tomographic models by convolution of the seismic structures with a resolution filter for the global model S40RTS. Quantitative comparison of synthetic signatures with global seismic observations beneath a number of hotspots indicates that more than half of all studied locations are underlain by low-velocity anomalies with widths and magnitudes compatible with thermal plumes. Other locations, e.g. Iceland, require plumes with time-dependent morphologies, modified by chemistry or phase buoyancy forces. I next forward model the predicted transition zone seismic structure for a number for thermal and thermochemical whole mantle plume scenarios, before commenting on suitability of using transition zone thickness beneath hotspots as a proxy for temperature. Lastly, I finish with a discussion of how such an analysis might be extended to other terrestrial planets, such as Mars

Inherited body : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Creative Writing at Massey University, Manawatū, New Zealand

Narrative ethics is a useful tool for approaching New Zealand historical fiction about family history because it looks to the risks and losses of appropriating family for the author, their subjects, and readers. In the following critical analysis I discuss three recent New Zealand novels based on family historical narratives, each of which depict characters attempting to write their own stories within power structures that threaten to silence them: Alison Wong’s As The Earth Turns Silver (2009), Paula Morris’s Rangatira (2011), and Kelly Ana Morey’s Bloom (2003). For a writer a narrative ethics analysis ensures they acknowledge the ethical implications of their work, not just for their own family, but for collective understanding. My novel Inherited Body fictionalises an incident from my family’s history about mental health and sits alongside a contemporary narrative that seeks to understand the possible causes of a psychotic break. A narrative ethics analysis has highlighted my dual role as reader/critic and writer. Wayne C. Booth’s discussion of narrative ethics emphasises the connection between writer, character and their readers. Adam Zachary Newton expands on this transactive connection and shows the ethical consequences of narrating story and fictionalising people, and the reciprocal claims connecting teller, listener, witness and reader in that process. As a reader, I took on an ethical responsibility to understand the texts, and as a writer, I attempted to understand the effect of my characters and readers of the book’s content. Connecting my critical and creative components with a narrative ethics framework ensures that I see both sides of narrative ethics

Russia Giving: Research on individual giving in Russia

This report presents the findings of research into individual giving in Russia and analyses the common giving patterns and habits of Russians -- the frequency and size of donations to NGOs, the ways in which donations are made, the main sources of information about NGOs, and which causes attract the most support, as well as the obstacles to and drivers for individual giving. The report draws parallels with the corresponding UK data and provides conclusions and recommendations for promoting individual giving to NGOs in Russia

A preliminary report on the mineralogy of the Tundulu and Songwe carbonatite complexes, Malawi

A group of samples from the Tundulu and Songwe carbonatite complexes in Malawi, supplied by Dr. Appleton, have been studied by various mineralogical techniques. The aim was to characterise them and assess their Usefulness as direct application fertilizers and sources of rare earth metals. A brief summary 9f the results obtained so far is given here and a full report will be made when the work is complete. Polished thin sections were made from 17 samples. These were examined on the optical microscope and 7 were analysed on the electron microprobe. This examination showed that there were three main rock types, apatite rocks, ferruginous carbonatites and calcite carbonatites(sovites) and the following report discusses them under theses broad headings