Greenstone belt tectonics: Thermal constraints

Archaean rocks provide a record of the early stages of planetary evolution. The interpretation is frustrated by the probable unrepresentative nature of the preserved crust and by the well known ambiguities of tectonic geological synthesis. Broad constraints can be placed on the tectonic processes in the early Earth from global scale modeling of thermal and chemical evolution of the Earth and its hydrosphere and atmosphere. The Archean record is the main test of such models. Available general model constraints are outlined based on the global tectonic setting within which Archaean crust evolved and on the direct evidence the Archaean record provides, particularly the thermal state of the early Earth

Proposed Reforms to Partial Defences and their Implications for Mentally Disordered Defendants

Partial defences are special defences only available in England & Wales to defendants charged with murder. They include provocation, diminished responsibility, infanticide and killing pursuant to a suicide pact. These are known as the ‘voluntary manslaughters’ where homicide with intent otherwise sufficient for murder (‘malice aforethought’) is reduced to manslaughter because of defined mitigating circumstances. Provocation and diminished responsibility have proved most problematic and will be the focus of this article. The mitigating factors arise from abnormal mental states, and psychiatric evidence has been at the centre of disputes regarding these defences. In this journal, Kerrigan set out recent problems that have developed with provocation in case law. The degree to which mental disorder can be considered when deciding the standard of behaviour required of the defendant who pleads ‘provocation’ has fluctuated markedly in recent years. Diminished responsibility, on the other hand, has aroused concern, inter alia, over its expansive use to cover a wide range of mental conditions, and the frequency with which expert psychiatrists comment on the ‘ultimate issue’ of whether all limbs of the test are met. Both problems might be said to arise from vague terms in the statutory definition that are incompatible with contemporary psychiatric practice.Following the controversial case of R v Smith (Morgan James), which permitted mental disorder a much greater effect on provocation, the United Kingdom Government asked the Law Commission to consider and report on the law and practice of the partial defences provided for by the Homicide Act 1957. This progressed to investigation into wider homicide law and a process of consultation and review which has now passed to the Ministry of Justice. This paper will outline briefly the review process before considering in greater detail the current proposals for new definitions of provocation and diminished responsibility. The Commission would like these to exist within a radically re-structured law of homicide. The implications for mentally disordered defendants and therefore expert psychiatric opinion will be considered

The Secretary of State for Justice has a duty to provide Offending Behaviour Programmes in prison – submissions to the contrary are lacking in realism!

R (on the application of Walker) v Secretary of State for Justice; R (on the application of James) v Secretary of State for Justice[2008] EWCA Civ 3

Saskatchewan wheat pool: A profile of one Canadian grain cooperative

Photographs not included in Web versio

The Virtual Armory

This project pioneered the interpretation of the Worcester Art MuseumÂ’s recently acquired collection of arms and armor through digital media. They developed an infrastructure for delivering digital content through the internet, while researching individual objects and analyzing audience data from feedback iPads in the museum galleries. Based on their findings, the team developed an educational, turn-based sword fighting game for deployment on tablets as part of the exhibition of a sixteenth-century training sword and a combat treatise from 1600

The reactive transport of Li as a monitor of weathering processes in kinetically limited weathering regimes

Analytical solutions to reactive-transport equations describing the evolution of Li concentrations and isotopic ratios are presented for one-dimensional flow paths where reaction stoichiometry is constant along the flow path. These solutions are considered appropriate for chemical weathering in rapidly eroding catchments. The solutions may be described by two dimensionless numbers; 1) a Damkӧhler number describing the product of reaction rate and fluid residence time, and 2) a net partition coefficient which describes the fraction of Li re-precipitated in secondary minerals as the product of a fluid-secondary mineral partition coefficient and the mass fraction of secondary mineral precipitates. In settings where water entering flow paths is dilute, Li concentrations will increase along the flow path until they reach a limiting value determined by the net partition coefficient. Simultaneously, 7Li/6Li isotopic ratios will increase to a limiting value of the source rock ratio minus the secondary mineral-fluid Li-isotopic fractionation factor. Waters with Li-isotopic ratios in excess of this limiting value must have evolved with a change of reaction stoichiometry and/or partition coefficient along the flow path such that at some point net removal of Li to secondary minerals exceeds that supplied by dissolution of primary minerals. The modelling shows that the multiple controls on chemical weathering rates (temperature, rainfall, erosion rate, hydrology) cannot be inferred from Li concentration and isotopic ratio data alone which only provide two independent constraints. Caution should be exercised in interpretation of oceanic Li records in terms of potential climatic variables. The model is illustrated by a set of Li concentration and isotopic ratio measurements on river waters and bed sands in the Alaknanda river basin which forms the headwaters of the Ganges. This illustrates how values of the Damkӧhler number and net partition coefficient can be used to trace weathering processes. Water samples from catchments with similar lithologies and climates scatter along contours of approximately constant net partition coefficient, reflecting similar reaction stoichiometries, but with more variable Damkӧhler numbers reflecting variations in flow path length, fluid flux and/or reaction rate. Samples from the lower, warmer and less rapidly eroding catchments have high 7Li/6Li isotopic ratios with lower Li concentrations and must reflect at least a two-stage weathering process where reaction stoichiometry and/or Li fluid-mineral partition coefficients change along the flow path so that net Li is removed in the later stages